[{"corr_author":"1","file_date_updated":"2024-10-24T08:09:13Z","type":"dissertation","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"last_name":"Sisak","id":"44A03D04-AEA4-11E9-B225-EA2DE6697425","full_name":"Sisak, Maria A","first_name":"Maria A"}],"oa":1,"OA_place":"publisher","_id":"18443","ddc":["516"],"file":[{"access_level":"open_access","success":1,"file_size":1672547,"relation":"main_file","date_created":"2024-10-23T14:42:45Z","checksum":"8c4893e726aaa4b3efb82758da9b6851","file_id":"18467","creator":"msisak","file_name":"MASisak_dissertation.pdf","date_updated":"2024-10-23T14:42:45Z","content_type":"application/pdf"},{"content_type":"application/x-zip-compressed","date_updated":"2024-10-24T08:09:13Z","file_name":"MASisak_source.zip","creator":"msisak","file_id":"18468","checksum":"1831b072e861a1e5481024ca9d02b036","date_created":"2024-10-23T14:43:56Z","relation":"source_file","file_size":617913,"access_level":"closed"}],"page":"178","keyword":["hyperkaehler geometry","branes","mirror symmetry","T-duality"],"status":"public","date_created":"2024-10-19T12:00:37Z","supervisor":[{"orcid":"0000-0002-9582-2634","first_name":"Tamás","full_name":"Hausel, Tamás","id":"4A0666D8-F248-11E8-B48F-1D18A9856A87","last_name":"Hausel"}],"language":[{"iso":"eng"}],"has_accepted_license":"1","month":"10","department":[{"_id":"GradSch"},{"_id":"TaHa"}],"date_updated":"2026-04-07T12:42:44Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"title":"T-dual branes on hyperkähler manifolds","citation":{"short":"M.A. Sisak, T-Dual Branes on Hyperkähler Manifolds, Institute of Science and Technology Austria, 2024.","apa":"Sisak, M. A. (2024). <i>T-dual branes on hyperkähler manifolds</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18443\">https://doi.org/10.15479/at:ista:18443</a>","ama":"Sisak MA. T-dual branes on hyperkähler manifolds. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18443\">10.15479/at:ista:18443</a>","chicago":"Sisak, Maria A. “T-Dual Branes on Hyperkähler Manifolds.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18443\">https://doi.org/10.15479/at:ista:18443</a>.","ista":"Sisak MA. 2024. T-dual branes on hyperkähler manifolds. Institute of Science and Technology Austria.","ieee":"M. A. Sisak, “T-dual branes on hyperkähler manifolds,” Institute of Science and Technology Austria, 2024.","mla":"Sisak, Maria A. <i>T-Dual Branes on Hyperkähler Manifolds</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18443\">10.15479/at:ista:18443</a>."},"date_published":"2024-10-24T00:00:00Z","year":"2024","doi":"10.15479/at:ista:18443","article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"]},"publication_status":"published","degree_awarded":"PhD","abstract":[{"lang":"eng","text":"In [KW06] Kapustin and Witten conjectured that there is a mirror symmetry relation between\r\nthe hyperkähler structures on certain Higgs bundle moduli spaces. As a consequence, they\r\nconjecture an equivalence between categories of BBB and BAA-branes. At the classical\r\nlevel, this mirror symmetry is given by T-duality between semi-flat hyperkähler structures on\r\nalgebraic integrable systems.\r\nIn this thesis, we investigate the T-duality relation between hyperkähler structures and the\r\ncorresponding branes on affine torus bundles. We use the techniques of generalized geometry\r\nto show that semi-flat hyperkähler structures are T-dual on algebraic integrable systems.\r\nWe also describe T-duality for generalized branes. Motivated by Fourier-Mukai transform\r\nwe upgrade the T-duality between generalized branes to T-duality of submanifolds endowed\r\nwith U(1)-bundles and connections. This T-duality in the appropriate context specializes to\r\nT-duality between BBB and BAA-branes.\r\n"}],"OA_type":"free access","oa_version":"Published Version","day":"24","alternative_title":["ISTA Thesis"],"project":[{"_id":"6286e8c4-2b32-11ec-9570-f5297902f67f","name":"Branes on hyperkähler manifolds","grant_number":"26069"}]},{"OA_place":"publisher","_id":"17485","oa":1,"related_material":{"record":[{"id":"18062","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"18061","status":"public"},{"status":"public","id":"17378","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"17087","status":"public"},{"status":"public","id":"14458","relation":"part_of_dissertation"}]},"type":"dissertation","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"id":"09a8f98d-ec99-11ea-ae11-c063a7b7fe5f","full_name":"Frantar, Elias","last_name":"Frantar","first_name":"Elias"}],"corr_author":"1","file_date_updated":"2024-09-06T16:24:59Z","language":[{"iso":"eng"}],"has_accepted_license":"1","acknowledged_ssus":[{"_id":"ScienComp"}],"date_created":"2024-09-02T11:01:48Z","status":"public","supervisor":[{"first_name":"Dan-Adrian","orcid":"0000-0003-3650-940X","last_name":"Alistarh","id":"4A899BFC-F248-11E8-B48F-1D18A9856A87","full_name":"Alistarh, Dan-Adrian"}],"page":"129","ddc":["000"],"file":[{"file_name":"thesis-final.zip","date_updated":"2024-09-05T12:04:11Z","content_type":"application/zip","creator":"efrantar","file_id":"17570","date_created":"2024-09-05T12:04:11Z","checksum":"5d785645805a78c5b4ce7cc3df557b09","access_level":"closed","file_size":1615167,"relation":"source_file"},{"date_updated":"2024-09-06T16:24:59Z","file_name":"frantar_thesis_final.pdf","content_type":"application/pdf","creator":"efrantar","file_id":"17880","date_created":"2024-09-06T16:24:59Z","checksum":"a9dd1c2d23734986924eb44ebb55fd8f","success":1,"access_level":"open_access","relation":"main_file","file_size":2376611}],"doi":"10.15479/at:ista:17485","article_processing_charge":"No","publication_identifier":{"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","publication_status":"published","degree_awarded":"PhD","citation":{"ama":"Frantar E. Compressing large neural networks : Algorithms, systems and scaling laws. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17485\">10.15479/at:ista:17485</a>","chicago":"Frantar, Elias. “Compressing Large Neural Networks : Algorithms, Systems and Scaling Laws.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17485\">https://doi.org/10.15479/at:ista:17485</a>.","short":"E. Frantar, Compressing Large Neural Networks : Algorithms, Systems and Scaling Laws, Institute of Science and Technology Austria, 2024.","apa":"Frantar, E. (2024). <i>Compressing large neural networks : Algorithms, systems and scaling laws</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17485\">https://doi.org/10.15479/at:ista:17485</a>","ieee":"E. Frantar, “Compressing large neural networks : Algorithms, systems and scaling laws,” Institute of Science and Technology Austria, 2024.","mla":"Frantar, Elias. <i>Compressing Large Neural Networks : Algorithms, Systems and Scaling Laws</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17485\">10.15479/at:ista:17485</a>.","ista":"Frantar E. 2024. Compressing large neural networks : Algorithms, systems and scaling laws. Institute of Science and Technology Austria."},"year":"2024","date_published":"2024-09-05T00:00:00Z","title":"Compressing large neural networks : Algorithms, systems and scaling laws","month":"09","department":[{"_id":"GradSch"},{"_id":"DaAl"}],"date_updated":"2026-04-07T12:43:04Z","alternative_title":["ISTA Thesis"],"project":[{"call_identifier":"H2020","_id":"268A44D6-B435-11E9-9278-68D0E5697425","name":"Elastic Coordination for Scalable Machine Learning","grant_number":"805223"}],"ec_funded":1,"day":"05","oa_version":"Published Version","abstract":[{"text":"Large language models (LLMs) have made tremendous progress in the past few years, from being able to generate coherent text to matching or surpassing humans in a wide variety of creative, knowledge or reasoning tasks. Much of this can be attributed to massively increased scale, both in the size of the model as well as the amount of training data, from 100s of millions to 100s of billions, or even trillions. This trend is expected to continue, which, although exciting, also raises major practical concerns. Already today's 100+ billion parameter LLMs require top-of-the-line hardware just to run. Hence, it is clear that sustaining these developments will require significant efficiency advances.\r\n\r\nHistorically, one of the most practical ways of improving model efficiency has been compression, especially in the form of sparsity or quantization. While this has been studied extensively in the past, existing accurate methods are all designed for models around 100 million parameters; scaling them up to ones literally 1000x larger is highly challenging. In this thesis, we introduce a new unified sparsification and quantization approach OBC, which through additional algorithmic enhancements leads to GPTQ and SparseGPT, the first techniques fast and accurate enough to compress 100+ billion parameter models to 4- or even 3-bit precision and 50% weight-sparsity, respectively. Additionally, we show how weight-only quantizion does not just bring space savings but also up to 4.5x faster generation speed, via custom GPU kernels.\r\n\r\nIn fact, we show for the first time that it is possible to develop an FP16 times INT4 mixed-precision matrix multiplication kernel, called Marlin, which comes close to simultaneously maximizing both memory and compute utilization, making weight-only quantization highly practical even for multi-user serving. Further, we demonstrate that GPTQ can be scaled to widely overparametrized trillion-parameter models, where extreme sub-1-bit compression rates can be achieved without any inference slow-down, by co-designing a bespoke entropy coding scheme together with an efficient kernel.\r\n\r\nFinally, we also study compression from the perspective of someone with access to massive amounts of compute resources for training large models completely from scratch. Here the key questions evolve around the joint scaling behavior between compression, model size, and amount of training data used. Based on extensive experimental results for both vision and text models, we introduce the first scaling law which accurately captures the relationship between weight-sparsity, number of non-zero weights and data. This further allows us to characterize the optimal sparsity, which we find to increase the longer a fixed cost model is being trained.\r\n\r\nOverall, this thesis presents contributions to three different angles of large model efficiency: affordable but accurate algorithms, highly efficient systems implementations, and fundamental scaling laws for compressed training.","lang":"eng"}]},{"_id":"17208","OA_place":"publisher","oa":1,"related_material":{"record":[{"status":"public","id":"10545","relation":"part_of_dissertation"},{"status":"public","id":"10067","relation":"part_of_dissertation"},{"status":"public","id":"17222","relation":"part_of_dissertation"},{"id":"13125","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"11471"}]},"author":[{"last_name":"Medina Ramos","full_name":"Medina Ramos, Raimel A","id":"CE680B90-D85A-11E9-B684-C920E6697425","first_name":"Raimel A","orcid":"0000-0002-5383-2869"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","type":"dissertation","file_date_updated":"2024-07-17T09:23:24Z","corr_author":"1","has_accepted_license":"1","acknowledged_ssus":[{"_id":"ScienComp"}],"language":[{"iso":"eng"}],"supervisor":[{"orcid":"0000-0002-2399-5827","first_name":"Maksym","id":"47809E7E-F248-11E8-B48F-1D18A9856A87","full_name":"Serbyn, Maksym","last_name":"Serbyn"}],"keyword":["Quantum computing","Variational Quantum Algorithms","Optimization"],"status":"public","date_created":"2024-07-09T09:14:24Z","page":"133","file":[{"date_created":"2024-07-09T09:21:44Z","checksum":"6f45273d04f4418bc2adc018baed0525","access_level":"closed","relation":"source_file","file_size":"14218691","date_updated":"2024-07-10T11:34:09Z","file_name":"Raimel_Thesis-Final.zip","content_type":"application/zip","creator":"rmedinar","file_id":"17212"},{"file_size":11253627,"relation":"main_file","access_level":"open_access","success":1,"checksum":"6724a95bec772dbabc0111b9f08a805e","date_created":"2024-07-17T09:23:24Z","file_id":"17275","creator":"rmedinar","content_type":"application/pdf","file_name":"Raimel_Thesis-20_pdfa.pdf","date_updated":"2024-07-17T09:23:24Z"}],"ddc":["539"],"degree_awarded":"PhD","publication_status":"published","publication_identifier":{"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","article_processing_charge":"No","doi":"10.15479/at:ista:17208","date_published":"2024-07-09T00:00:00Z","year":"2024","citation":{"ista":"Medina Ramos RA. 2024. Exploring the optimization landscape of variational quantum algorithms. Institute of Science and Technology Austria.","ieee":"R. A. Medina Ramos, “Exploring the optimization landscape of variational quantum algorithms,” Institute of Science and Technology Austria, 2024.","mla":"Medina Ramos, Raimel A. <i>Exploring the Optimization Landscape of Variational Quantum Algorithms</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17208\">10.15479/at:ista:17208</a>.","short":"R.A. Medina Ramos, Exploring the Optimization Landscape of Variational Quantum Algorithms, Institute of Science and Technology Austria, 2024.","apa":"Medina Ramos, R. A. (2024). <i>Exploring the optimization landscape of variational quantum algorithms</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17208\">https://doi.org/10.15479/at:ista:17208</a>","ama":"Medina Ramos RA. Exploring the optimization landscape of variational quantum algorithms. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17208\">10.15479/at:ista:17208</a>","chicago":"Medina Ramos, Raimel A. “Exploring the Optimization Landscape of Variational Quantum Algorithms.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17208\">https://doi.org/10.15479/at:ista:17208</a>."},"title":"Exploring the optimization landscape of variational quantum algorithms","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"date_updated":"2026-04-07T12:43:22Z","month":"07","department":[{"_id":"GradSch"},{"_id":"MaSe"}],"project":[{"grant_number":"850899","call_identifier":"H2020","name":"Non-Ergodic Quantum Matter: Universality, Dynamics and Control","_id":"23841C26-32DE-11EA-91FC-C7463DDC885E"}],"alternative_title":["ISTA Thesis"],"day":"09","oa_version":"Published Version","ec_funded":1,"abstract":[{"lang":"eng","text":"Can current quantum computers provide a speedup over their classical counterparts for some kinds of problems? In this thesis, with a focus on ground state search/preparation, we address some of the challenges that both quantum annealing and variational quantum algorithms suffer from, hindering any possible practical speedup in comparison to the best classical counterparts. \r\n\r\nIn the first part of the thesis, we study the performance of quantum annealing for solving a particular combinatorial optimization problem called 3-XOR satisfability (3-XORSAT). The classical problem is mapped into a ground state search of a 3-local classical Hamiltonian $H_C$. We consider how modifying the initial problem, by adding more interaction terms to the corresponding Hamiltonian, leads to the emergence of a first-order phase transition during the annealing process. This phenomenon causes the total annealing duration, $T$, required to prepare the ground state of $H_C$ with a high probability to increase exponentially with the size of the problem. Our findings indicate that with the growing complexity of problem instances, the likelihood of encountering first-order phase transitions also increases, making quantum annealing an impractical solution for these types of combinatorial optimization problems.\r\n\r\nIn the second part, we focus on the problem of barren plateaus in generic variational quantum algorithms. Barren plateaus correspond to flat regions in the parameter space where the gradient of the cost function is zero in expectation, and with the variance decaying exponentially with the system size, thus obstructing an efficient parameter optimization.  We propose an algorithm to circumvent Barren Plateaus by monitoring the entanglement entropy of k-local reduced density matrices, alongside a method for estimating entanglement entropy via classical shadow tomography. We illustrate the approach with the paradigmatic example of the variational quantum eigensolver, and show that our algorithm effectively avoids barren plateaus in the initialization as well as during the optimization stage. \r\n\r\nLastly, in the last two Chapters of this thesis, we focus on the quantum approximate optimization algorithm (QAOA), originally introduced as an algorithm for solving generic combinatorial optimization problems in near-term quantum devices. Specifically, we focus on how to develop rigorous initialization strategies with guarantee improvement. Our motivation for this study lies in that for random initialization, the optimization typically leads to local minima with poor performance. Our main result corresponds to the analytical construction of index-1 saddle points or transition states, stationary points with a single direction of descent, as a tool for systematically exploring the QAOA optimization landscape. This leads us to propose a novel greedy parameter initialization strategy that guarantees for the energy to decrease with an increasing number of circuit layers. Furthermore, with precise estimates for the negative Hessian eigenvalue and its eigenvector, we establish a lower bound for energy improvement following a QAOA iteration."}]},{"oa":1,"related_material":{"record":[{"status":"public","id":"18293","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"18294"},{"relation":"part_of_dissertation","status":"public","id":"18295"},{"relation":"part_of_dissertation","id":"18173","status":"public"}]},"_id":"18132","OA_place":"publisher","file_date_updated":"2024-09-25T14:08:57Z","corr_author":"1","author":[{"last_name":"Glas","full_name":"Glas, Jakob","id":"d6423cba-dc74-11ea-a0a7-ee61689ff5fb","first_name":"Jakob"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","type":"dissertation","supervisor":[{"first_name":"Timothy D","orcid":"0000-0002-8314-0177","last_name":"Browning","full_name":"Browning, Timothy D","id":"35827D50-F248-11E8-B48F-1D18A9856A87"}],"status":"public","date_created":"2024-09-23T18:58:08Z","has_accepted_license":"1","language":[{"iso":"eng"}],"file":[{"file_id":"18133","creator":"jglas","date_updated":"2024-09-23T18:49:22Z","file_name":"PhDthesis (3).zip","content_type":"application/x-zip-compressed","access_level":"closed","file_size":5382106,"relation":"source_file","date_created":"2024-09-23T18:49:22Z","checksum":"2f8cf5cefdab108b1979caa8146cae9a"},{"content_type":"application/pdf","date_updated":"2024-09-25T14:08:57Z","file_name":"example-phd.pdf","creator":"jglas","file_id":"18140","checksum":"08bb6f14c42b47ff25882a2ce3ea0d8a","date_created":"2024-09-25T14:08:57Z","relation":"main_file","file_size":2380127,"access_level":"open_access","success":1}],"ddc":["512"],"page":"195","date_published":"2024-09-23T00:00:00Z","year":"2024","citation":{"chicago":"Glas, Jakob. “Counting Rational Points over Function Fields.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18132\">https://doi.org/10.15479/at:ista:18132</a>.","ama":"Glas J. Counting rational points over function fields. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18132\">10.15479/at:ista:18132</a>","apa":"Glas, J. (2024). <i>Counting rational points over function fields</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18132\">https://doi.org/10.15479/at:ista:18132</a>","short":"J. Glas, Counting Rational Points over Function Fields, Institute of Science and Technology Austria, 2024.","mla":"Glas, Jakob. <i>Counting Rational Points over Function Fields</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18132\">10.15479/at:ista:18132</a>.","ieee":"J. Glas, “Counting rational points over function fields,” Institute of Science and Technology Austria, 2024.","ista":"Glas J. 2024. Counting rational points over function fields. Institute of Science and Technology Austria."},"publication_status":"published","degree_awarded":"PhD","publication_identifier":{"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","article_processing_charge":"No","doi":"10.15479/at:ista:18132","tmp":{"image":"/images/cc_by_nc.png","legal_code_url":"https://creativecommons.org/licenses/by-nc/4.0/legalcode","name":"Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)","short":"CC BY-NC (4.0)"},"date_updated":"2026-04-07T12:53:54Z","department":[{"_id":"GradSch"},{"_id":"TiBr"}],"month":"09","title":"Counting rational points over function fields","oa_version":"Published Version","day":"23","project":[{"_id":"bd8a4fdc-d553-11ed-ba76-80a0167441a3","name":"Rational curves via function field analytic number theory","grant_number":"P36278"}],"alternative_title":["ISTA Thesis"],"abstract":[{"lang":"eng","text":"In this thesis, we are dealing with both arithmetic and geometric problems coming from the\r\nstudy of rational points with a particular focus on function fields over finite fields:\r\n(1) Using the circle method we produce upper bounds for the number of rational points of\r\nbounded height on diagonal cubic surfaces and fourfolds over Fq(t). This is based on\r\njoint work with Leonhard Hochfilzer.\r\n(2) We study rational points on smooth complete intersections X defined by cubic and\r\nquadratic hypersurfaces over Fq(t). We refine the Farey dissection of the “unit square”\r\ndeveloped by Vishe [202] and use the circle method with a Kloosterman refinement to\r\nestablish an asymptotic formula for the number of rational points of bounded height on\r\nX when dim(X) ≥ 23. Under the same hypotheses, we also verify weak approximation.\r\n(3) In joint work with Hochfilzer, we obtain upper bounds for the number of rational points of\r\nbounded height on del Pezzo surfaces of low degree over any global field. Our approach\r\nis to take hyperplane sections, which reduces the problem to uniform estimates for the\r\nnumber of rational points on curves.\r\n(4) We develop a version of the circle method capable of counting Fq-points on jet schemes\r\nof moduli spaces of rational curves on hypersurfaces. Combining this with a spreading\r\nout argument and a result of Mustaţă [150], this allows us to show that these moduli\r\nspaces only have canonical singularities under suitable assumptions on the degree and the\r\ndimension.\r\nIn addition, we give an overview of guiding questions and conjectures in the field of rational\r\npoints and explain the basic mechanism underlying the circle method.\r\n"}]},{"abstract":[{"text":"Many chemical and physical properties of materials are determined by the material’s shape,\r\nfor example the size of its pores and the width of its tunnels. This makes materials science\r\na prime application area for geometrical and topological methods. Nevertheless many\r\nmethods in topological data analysis have not been satisfyingly extended to the needs of\r\nmaterials science. This thesis provides new methods and new mathematical theorems\r\ntargeted at those specific needs by answering four different research questions. While the\r\nmotivation for each of the research questions arises from materials science, the methods\r\nare versatile and can be applied in different areas as well. \r\n\r\nThe first research question is concerned with image data, for example a three-dimensional\r\ncomputed tomography (CT) scan of a material, like sand or stone. There are two commonly\r\nused topologies for digital images and depending on the application either of them might be\r\nrequired. However, software for computing the topological data analysis method persistence\r\nhomology, usually supports only one of the two topologies. We answer the question how to\r\ncompute persistent homology of an image with respect to one of the two topologies using\r\nsoftware that is intended for the other topology. \r\n\r\nThe second research question is concerned with image data as well, and asks how much\r\nof the topological information of an image is lost when the resolution is coarsened. As\r\ncomputer tomography scanners are more expensive the higher the resolution, it is an\r\nimportant question in materials science to know which resolution is enough to get satisfying\r\npersistent homology. We give theoretical bounds on the information loss based on different\r\ngeometrical properties of the object to be scanned. In addition, we conduct experiments on\r\nsand and stone CT image data. \r\n\r\nThe third research question is motivated by comparing crystalline materials efficiently. As\r\nthe atoms within a crystal repeat periodically, crystalline materials are either modeled by\r\nunmanageable infinite periodic point sets, or by one of their fundamental domains, which is\r\nunstable under perturbation. Therefore a fingerprint of crystalline materials is needed, with\r\nappropriate properties such that comparing the crystals can be eased by comparing the\r\nfingerprints instead. We define the density fingerprint and prove the necessary properties. \r\n\r\nThe fourth research question is motivated by studying the hole-structure or connectedness,\r\ni.e. persistent homology or merge trees, of crystalline materials. A common way to deal\r\nwith periodicity is to take a fundamental domain and identify opposite boundaries to form a\r\ntorus. However, computing persistent homology or merge trees on that torus loses some\r\nof the information materials scientists are interested in and is additionally not stable under\r\ncertain noise. We therefore decorate the merge tree stemming from the torus with additional\r\ninformation describing the density and growth rate of the periodic copies of a component\r\nwithin a growing spherical window. We prove all desired properties, like stability and efficient\r\ncomputability.","lang":"eng"}],"ec_funded":1,"oa_version":"Published Version","day":"17","alternative_title":["ISTA Thesis"],"project":[{"grant_number":"788183","_id":"266A2E9E-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"Alpha Shape Theory Extended"}],"date_updated":"2026-04-07T12:54:10Z","month":"12","department":[{"_id":"GradSch"},{"_id":"HeEd"}],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"title":"New methods for applying topological data analysis to materials science","year":"2024","date_published":"2024-12-17T00:00:00Z","citation":{"ista":"Heiss T. 2024. New methods for applying topological data analysis to materials science. Institute of Science and Technology Austria.","ieee":"T. Heiss, “New methods for applying topological data analysis to materials science,” Institute of Science and Technology Austria, 2024.","mla":"Heiss, Teresa. <i>New Methods for Applying Topological Data Analysis to Materials Science</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18667\">10.15479/at:ista:18667</a>.","short":"T. Heiss, New Methods for Applying Topological Data Analysis to Materials Science, Institute of Science and Technology Austria, 2024.","apa":"Heiss, T. (2024). <i>New methods for applying topological data analysis to materials science</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18667\">https://doi.org/10.15479/at:ista:18667</a>","ama":"Heiss T. New methods for applying topological data analysis to materials science. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18667\">10.15479/at:ista:18667</a>","chicago":"Heiss, Teresa. “New Methods for Applying Topological Data Analysis to Materials Science.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18667\">https://doi.org/10.15479/at:ista:18667</a>."},"article_processing_charge":"No","publication_identifier":{"isbn":["978-3-99078-052-7"],"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","doi":"10.15479/at:ista:18667","publication_status":"published","degree_awarded":"PhD","ddc":["514","516","004"],"file":[{"date_created":"2024-12-19T10:24:46Z","checksum":"247bb057aed2fba1cd4711917aaa2d77","success":1,"access_level":"open_access","relation":"main_file","file_size":7752253,"file_name":"Teresa_Heiss_PhD_Thesis_final.pdf","date_updated":"2024-12-19T10:24:46Z","content_type":"application/pdf","file_id":"18686","creator":"theiss"},{"file_id":"18687","creator":"theiss","content_type":"application/zip","file_name":"PhD_Thesis.zip","date_updated":"2024-12-19T10:24:50Z","file_size":17197731,"relation":"source_file","access_level":"closed","checksum":"9648b45c07a008ee11a07f99856a139d","date_created":"2024-12-19T10:24:50Z"}],"page":"111","status":"public","date_created":"2024-12-17T16:17:55Z","keyword":["persistent homology","topological data analysis","periodic","crystalline materials","images","fingerprint"],"supervisor":[{"orcid":"0000-0002-9823-6833","first_name":"Herbert","full_name":"Edelsbrunner, Herbert","id":"3FB178DA-F248-11E8-B48F-1D18A9856A87","last_name":"Edelsbrunner"}],"language":[{"iso":"eng"}],"has_accepted_license":"1","corr_author":"1","file_date_updated":"2024-12-19T10:24:50Z","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","acknowledgement":"I was supported by the European Research Council (ERC) Horizon 2020 project\r\n“Alpha Shape Theory Extended” No. 788183 and by the Pöttinger Scholarship. In addition,\r\nI am very thankful for having been able to attend the second Workshop for Women in\r\nComputational Topology in July 2019, funded by the Mathematical Sciences Institute at\r\nANU, the US National Science Foundation through the award CCF-1841455, the Australian\r\nMathematical Sciences Institute and the Association for Women in Mathematics. Two of the\r\nprojects presented in this thesis started there. One of them reached completion thanks to\r\nfunding from the MSRI Summer Research in Mathematics program awarded to me and my\r\ncollaborators in 2020.","author":[{"last_name":"Heiss","id":"4879BB4E-F248-11E8-B48F-1D18A9856A87","full_name":"Heiss, Teresa","orcid":"0000-0002-1780-2689","first_name":"Teresa"}],"type":"dissertation","oa":1,"related_material":{"record":[{"id":"10828","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"11440","status":"public"},{"id":"18673","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"9345"}]},"_id":"18667","OA_place":"publisher"},{"_id":"14711","OA_place":"publisher","oa":1,"related_material":{"record":[{"status":"public","id":"10787","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"10658"},{"relation":"part_of_dissertation","status":"public","id":"14732"}]},"author":[{"first_name":"Oluwafunmilola O","orcid":"0000-0003-1971-8314","last_name":"Olusanya","id":"41AD96DC-F248-11E8-B48F-1D18A9856A87","full_name":"Olusanya, Oluwafunmilola O"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","type":"dissertation","corr_author":"1","file_date_updated":"2024-01-03T18:31:34Z","language":[{"iso":"eng"}],"acknowledged_ssus":[{"_id":"SSU"}],"has_accepted_license":"1","status":"public","date_created":"2023-12-26T22:49:53Z","supervisor":[{"last_name":"Barton","id":"4880FE40-F248-11E8-B48F-1D18A9856A87","full_name":"Barton, Nicholas H","orcid":"0000-0002-8548-5240","first_name":"Nicholas H"},{"first_name":"Jitka","full_name":"Polechova, Jitka","last_name":"Polechova"},{"full_name":"Sachdeva, Himani","last_name":"Sachdeva","first_name":"Himani"}],"page":"183","ddc":["576"],"file":[{"creator":"oolusany","file_id":"14730","content_type":"application/zip","file_name":"FinalSubmission_Thesis_OLUSANYA.zip","date_updated":"2024-01-03T18:30:13Z","relation":"source_file","file_size":16986244,"access_level":"closed","checksum":"de179b1c6758f182ff0c70d8b38c1501","date_created":"2024-01-03T18:30:13Z"},{"date_updated":"2024-01-03T18:31:34Z","file_name":"FinalSubmission2_Thesis_OLUSANYA.pdf","content_type":"application/pdf","creator":"oolusany","file_id":"14731","date_created":"2024-01-03T18:31:34Z","checksum":"0e331585e3cd4823320aab4e69e64ccf","success":1,"access_level":"open_access","relation":"main_file","file_size":6460403}],"publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","doi":"10.15479/at:ista:14711","degree_awarded":"PhD","publication_status":"published","year":"2024","date_published":"2024-01-19T00:00:00Z","citation":{"ista":"Olusanya OO. 2024. Local adaptation, genetic load and extinction in metapopulations. Institute of Science and Technology Austria.","ieee":"O. O. Olusanya, “Local adaptation, genetic load and extinction in metapopulations,” Institute of Science and Technology Austria, 2024.","mla":"Olusanya, Oluwafunmilola O. <i>Local Adaptation, Genetic Load and Extinction in Metapopulations</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:14711\">10.15479/at:ista:14711</a>.","short":"O.O. Olusanya, Local Adaptation, Genetic Load and Extinction in Metapopulations, Institute of Science and Technology Austria, 2024.","apa":"Olusanya, O. O. (2024). <i>Local adaptation, genetic load and extinction in metapopulations</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:14711\">https://doi.org/10.15479/at:ista:14711</a>","ama":"Olusanya OO. Local adaptation, genetic load and extinction in metapopulations. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:14711\">10.15479/at:ista:14711</a>","chicago":"Olusanya, Oluwafunmilola O. “Local Adaptation, Genetic Load and Extinction in Metapopulations.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:14711\">https://doi.org/10.15479/at:ista:14711</a>."},"title":"Local adaptation, genetic load and extinction in metapopulations","date_updated":"2026-04-07T12:54:29Z","month":"01","department":[{"_id":"NiBa"},{"_id":"GradSch"}],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"alternative_title":["ISTA Thesis"],"project":[{"grant_number":"665385","call_identifier":"H2020","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","name":"International IST Doctoral Program"},{"grant_number":"P32896","_id":"c08d3278-5a5b-11eb-8a69-fdb09b55f4b8","name":"Causes and consequences of population fragmentation"},{"name":"Polygenic Adaptation in a Metapopulation","_id":"34c872fe-11ca-11ed-8bc3-8534b82131e6","grant_number":"26380"}],"ec_funded":1,"oa_version":"Published Version","day":"19","abstract":[{"text":"In nature, different species find their niche in a range of environments, each with its unique characteristics. While some thrive in uniform (homogeneous) landscapes where environmental conditions stay relatively consistent across space, others traverse the complexities of spatially heterogeneous terrains. Comprehending how species are distributed and how they interact within these landscapes holds the key to gaining insights into their evolutionary dynamics while also informing conservation and management strategies.\r\n\r\nFor species inhabiting heterogeneous landscapes, when the rate of dispersal is low compared to spatial fluctuations in selection pressure, localized adaptations may emerge. Such adaptation in response to varying selection strengths plays an important role in the persistence of populations in our rapidly changing world. Hence, species in nature are continuously in a struggle to adapt to local environmental conditions, to ensure their continued survival. Natural populations can often adapt in time scales short enough for evolutionary changes to influence ecological dynamics and vice versa, thereby creating a feedback between evolution and demography. The analysis of this feedback and the relative contributions of gene flow, demography, drift, and natural selection to genetic variation and differentiation has remained a recurring theme in evolutionary biology. Nevertheless, the effective role of these forces in maintaining variation and shaping patterns of diversity is not fully understood. Even in homogeneous environments devoid of local adaptations, such understanding remains elusive. Understanding this feedback is crucial, for example in determining the conditions under which extinction risk can be mitigated in peripheral populations subject to deleterious mutation accumulation at the edges of species’ ranges\r\nas well as in highly fragmented populations.\r\n\r\nIn this thesis we explore both uniform and spatially heterogeneous metapopulations, investigating and providing theoretical insights into the dynamics of local adaptation in the latter and examining the dynamics of load and extinction as well as the impact of joint ecological and evolutionary (eco-evolutionary) dynamics in the former. The thesis is divided into 5 chapters.\r\n\r\nChapter 1 provides a general introduction into the subject matter, clarifying concepts and ideas used throughout the thesis. In chapter 2, we explore how fast a species distributed across a heterogeneous landscape adapts to changing conditions marked by alterations in carrying capacity, selection pressure, and migration rate.\r\n\r\nIn chapter 3, we investigate how migration selection and drift influences adaptation and the maintenance of variation in a metapopulation with three habitats, an extension of previous models of adaptation in two habitats. We further develop analytical approximations for the critical threshold required for polymorphism to persist.\r\n\r\nThe focus of chapter 4 of the thesis is on understanding the interplay between ecology and evolution as coupled processes. We investigate how eco-evolutionary feedback between migration, selection, drift, and demography influences eco-evolutionary outcomes in marginal populations subject to deleterious mutation accumulation. Using simulations as well as theoretical approximations of the coupled dynamics of population size and allele frequency, we analyze how gene flow from a large mainland source influences genetic load and population size on an island (i.e., in a marginal population) under genetically realistic assumptions. Analyses of this sort are important because small isolated populations, are repeatedly affected by complex interactions between ecological and evolutionary processes, which can lead to their death. Understanding these interactions can therefore provide an insight into the conditions under which extinction risk can be mitigated in peripheral populations thus, contributing to conservation and restoration efforts.\r\n\r\nChapter 5 extends the analysis in chapter 4 to consider the dynamics of load (due to deleterious mutation accumulation) and extinction risk in a metapopulation. We explore the role of gene flow, selection, and dominance on load and extinction risk and further pinpoint critical thresholds required for metapopulation persistence.\r\n\r\nOverall this research contributes to our understanding of ecological and evolutionary mechanisms that shape species’ persistence in fragmented landscapes, a crucial foundation for successful conservation efforts and biodiversity management.","lang":"eng"}]},{"_id":"17156","OA_place":"publisher","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"17157"}]},"oa":1,"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"full_name":"Rychlewicz, Kamil P","id":"85A07246-A8BF-11E9-B4FA-D9E3E5697425","last_name":"Rychlewicz","first_name":"Kamil P"}],"type":"dissertation","file_date_updated":"2024-06-26T21:00:14Z","corr_author":"1","has_accepted_license":"1","language":[{"iso":"eng"}],"supervisor":[{"orcid":"0000-0002-9582-2634","first_name":"Tamás","last_name":"Hausel","id":"4A0666D8-F248-11E8-B48F-1D18A9856A87","full_name":"Hausel, Tamás"}],"status":"public","keyword":["equivariant cohomology","zero schemes","algebraic groups","Lie algebras"],"date_created":"2024-06-23T15:07:06Z","page":"117","file":[{"access_level":"closed","relation":"source_file","file_size":2761814,"date_created":"2024-06-26T20:56:27Z","checksum":"1610063569f5452f8a5acef728c2fc26","creator":"krychlew","file_id":"17179","file_name":"thesis.zip","date_updated":"2024-06-26T21:00:14Z","content_type":"application/zip"},{"date_created":"2024-06-26T20:58:24Z","checksum":"7bbadb1fbc9ed2a1ecf54597f88af99c","access_level":"open_access","relation":"main_file","file_size":3695952,"file_name":"thesis.pdf","date_updated":"2024-06-26T20:58:24Z","content_type":"application/pdf","file_id":"17180","creator":"krychlew"}],"ddc":["516"],"publication_status":"published","degree_awarded":"PhD","publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","doi":"10.15479/at:ista:17156","date_published":"2024-06-25T00:00:00Z","year":"2024","citation":{"ieee":"K. P. Rychlewicz, “Equivariant cohomology and rings of functions,” Institute of Science and Technology Austria, 2024.","mla":"Rychlewicz, Kamil P. <i>Equivariant Cohomology and Rings of Functions</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17156\">10.15479/at:ista:17156</a>.","ista":"Rychlewicz KP. 2024. Equivariant cohomology and rings of functions. Institute of Science and Technology Austria.","ama":"Rychlewicz KP. Equivariant cohomology and rings of functions. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17156\">10.15479/at:ista:17156</a>","chicago":"Rychlewicz, Kamil P. “Equivariant Cohomology and Rings of Functions.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17156\">https://doi.org/10.15479/at:ista:17156</a>.","short":"K.P. Rychlewicz, Equivariant Cohomology and Rings of Functions, Institute of Science and Technology Austria, 2024.","apa":"Rychlewicz, K. P. (2024). <i>Equivariant cohomology and rings of functions</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17156\">https://doi.org/10.15479/at:ista:17156</a>"},"title":"Equivariant cohomology and rings of functions","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"date_updated":"2026-04-07T12:55:46Z","month":"06","department":[{"_id":"TaHa"},{"_id":"GradSch"}],"project":[{"name":"Topology of open smooth varieties with a torus action","_id":"34cd0f74-11ca-11ed-8bc3-bf0492a14a24","grant_number":"26525"}],"alternative_title":["ISTA Thesis"],"day":"25","oa_version":"Published Version","abstract":[{"text":"This dissertation is the summary of the author’s work, concerning the relations between\r\ncohomology rings of algebraic varieties and rings of functions on zero schemes and fixed\r\npoint schemes. For most of the thesis, the focus is on smooth complex varieties with\r\nan action of a principally paired group, e.g. a parabolic subgroup of a reductive group.\r\nThe fundamental theorem 5.2.11 from co-authored article [66] says that if the principal\r\nnilpotent has a unique zero, then the zero scheme over the Kostant section is isomorphic\r\nto the spectrum of the equivariant cohomology ring, remembering the grading in terms of\r\na C^* action. A similar statement is proved also for the G-invariant functions on the total\r\nzero scheme over the whole Lie algebra. Additionally, we are able to prove an analogous\r\nresult for the GKM spaces, which poses the question on a joint generalisation.\r\nWe also tackle the situation of a singular variety. As long as it is embedded in a smooth\r\nvariety with regular action, we are able to study its cohomology as well by means of\r\nthe zero scheme. In case of e.g. Schubert varieties this determines the cohomology ring\r\ncompletely. In largest generality, this allows us to see a significant part of the cohomology\r\nring.\r\nWe also show (Theorem 6.2.1) that the cohomology ring of spherical varieties appears as\r\nthe ring of functions on the zero scheme. The computational aspect is not easy, but one\r\ncan hope that this can bring some concrete information about such cohomology rings.\r\nLastly, the K-theory conjecture 6.3.1 is studied, with some results attained for GKM\r\nspaces.\r\nThe thesis includes also an introduction to group actions on algebraic varieties. In\r\nparticular, the vector fields associated to the actions are extensively studied. We also\r\nprovide a version of the Kostant section for arbitrary principally paired group, which\r\nparametrises the regular orbits in the Lie algebra of an algebraic group. Before proving\r\nthe main theorem, we also include a historical overview of the field. In particular we bring\r\ntogether the results of Akyildiz, Carrell and Lieberman on non-equivariant cohomology\r\nrings.","lang":"eng"}]},{"alternative_title":["ISTA Thesis"],"project":[{"grant_number":"P32166","name":"Snapdragon Speciation","_id":"05959E1C-7A3F-11EA-A408-12923DDC885E"},{"grant_number":"101055327","_id":"bd6958e0-d553-11ed-ba76-86eba6a76c00","name":"Understanding the evolution of continuous genomes"}],"oa_version":"Published Version","day":"07","OA_type":"gold","abstract":[{"text":"Understanding the role of evolutionary processes in shaping genetic variation has been a\r\nprimary goal in evolutionary genetics. In this regard, a key question is how genetically\r\ndistinct populations evolve in the face of gene flow, thereby generating genetic and\r\nphenotypic divergence and reproductive isolation (RI). This requires quantifying the role\r\nand relative contributions of prezygotic and postzygotic isolating mechanisms on the\r\nreduction of gene exchange between populations, and identifying regions in the genome\r\nthat mediate RI, which is often polygenic. Further, this needs distinguishing neutral and\r\nselected regions in the genome, and discerning how selection influences patterns of neutral\r\ndivergence.\r\nPopulation structure, defined as any deviation from panmixia, such as geographic distribution, movement and mating patterns of individuals, influences how genetic variation is\r\nstructured in space and shapes the neutral null model. Availability of large scale spatial\r\ngenomic datasets now enables us to detect signatures of population structure in genetic\r\ndata and infer population genetic parameters. Such inferences are crucial and have wide\r\napplications in biodiversity, conservation genetics, population management and medical\r\ngenetics. However, inferences are based on assumptions that do not always match the\r\ncomplex reality, thus leading to erroneous conclusions. Moreover, the role and interaction\r\nof heterogeneous population density and dispersal, which are ubiquitous in nature, has\r\nbeen challenging to study owing to their mathematical complexity. In such scenarios,\r\nfeedback between theory, data and simulations can prove to be useful.\r\nIn this thesis, I examine the effect of population structure on neutral genetic variation\r\nand barriers to gene exchange in hybridising populations, thereby bridging together the\r\nfields of spatial population genetics and speciation.\r\nDespite being a key concept in speciation, reproductive isolation (RI) lacks a quantitative\r\ndefinition and has been used and measured differently across different fields. Chapter 2\r\ngives a quantitative definition of RI, in terms of the effect of genetic differences on gene\r\nflow. We give analytical predictions for RI in a range of scenarios, in terms of effective migration rates for discrete populations and barrier strength for continuous populations.\r\nIn addition to this, we discuss current measures of RI and their limitations, and propose\r\nthe need for new measures that combine organismal and genetic perspectives of RI.\r\nIn chapter 3, I examine the combined effect of assortative mating, sexual selection\r\nand viability selection on RI. For this, we consider a polygenic ‘magic’ trait under a\r\nmainland-island model. We obtain novel theoretical predictions for molecular divergence\r\nin terms of effective migration rates, which bears a simple relationship to measurable\r\nfitness components of migrants and various early generation hybrids. We explore the\r\nconditions under which local adaptation can be maintained despite maladaptive gene flow\r\nand quantify the relative contributions of viability and sexual selection to genome-wide\r\nbarriers to gene flow.\r\nThe next two chapters of the thesis focus on a hybrid zone of Antirrhinum majus that\r\nconsist of two subspecies- the magenta flowered A. m. pseudomajus and the yellow\r\nflowered A.m. striatum. Previous studies have suggested that flower colour is target of\r\npollinator mediated selection and is influenced only by few genes. While these regions\r\nshow high genetic differentiation between the subspecies, the rest of the genome is seen\r\nto be well mixed. Chapter 4 examines the effects of heterogeneous population density\r\nand leptokurtic dispersal on isolation by distance and the distribution of heterozygosity\r\nby focusing on non-flower colour markers.\r\nChapter 5 analyses cline shapes and associations among 6 focal flower colour markers to\r\nunderstand how selection and dispersal maintain this hybrid zone. We see sharp coincident\r\nstepped clines at all loci and positive associations throughout the hybrid zone, contrary to\r\nthe expected patterns from diffusive gene flow. With a novel scheme of inferring dispersal\r\ncombined with multilocus simulations, we show that stepped clines do not reflect genetic\r\nbarriers to gene flow, but are rather a result of long-distance migration. This framework\r\nallows us to get realistic estimates gene flow and selection and shows how traditional cline\r\nanalysis may lead to inaccurate conclusions when assumptions of the theory are not met.\r\nOverall, this thesis investigates how different features of population structure leave\r\ndetectable signatures in genetic variation, namely in patterns of isolation by distance,\r\nlinkage disequilibrium and genetic divergence. It also highlights how effective migration\r\nrates provide useful way of analysing polygenic architectures and shed new light into\r\nhybrid zones. In doing so, I identify scenarios when simple models become insufficient\r\nand suggest possibe directions by combining genetic data with simulations.","lang":"eng"}],"publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","doi":"10.15479/at:ista:18515","degree_awarded":"PhD","publication_status":"published","year":"2024","date_published":"2024-11-07T00:00:00Z","citation":{"ieee":"P. Surendranadh, “Effect of population structure on neutral genetic variation and barriers to gene exchange,” Institute of Science and Technology Austria, 2024.","mla":"Surendranadh, Parvathy. <i>Effect of Population Structure on Neutral Genetic Variation and Barriers to Gene Exchange</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18515\">10.15479/at:ista:18515</a>.","ista":"Surendranadh P. 2024. Effect of population structure on neutral genetic variation and barriers to gene exchange. Institute of Science and Technology Austria.","ama":"Surendranadh P. Effect of population structure on neutral genetic variation and barriers to gene exchange. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18515\">10.15479/at:ista:18515</a>","chicago":"Surendranadh, Parvathy. “Effect of Population Structure on Neutral Genetic Variation and Barriers to Gene Exchange.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18515\">https://doi.org/10.15479/at:ista:18515</a>.","short":"P. Surendranadh, Effect of Population Structure on Neutral Genetic Variation and Barriers to Gene Exchange, Institute of Science and Technology Austria, 2024.","apa":"Surendranadh, P. (2024). <i>Effect of population structure on neutral genetic variation and barriers to gene exchange</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18515\">https://doi.org/10.15479/at:ista:18515</a>"},"title":"Effect of population structure on neutral genetic variation and barriers to gene exchange","date_updated":"2026-04-07T12:56:52Z","department":[{"_id":"GradSch"},{"_id":"NiBa"}],"month":"11","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"language":[{"iso":"eng"}],"has_accepted_license":"1","acknowledged_ssus":[{"_id":"ScienComp"}],"status":"public","date_created":"2024-11-06T21:25:37Z","supervisor":[{"last_name":"Barton","id":"4880FE40-F248-11E8-B48F-1D18A9856A87","full_name":"Barton, Nicholas H","orcid":"0000-0002-8548-5240","first_name":"Nicholas H"}],"page":"219","ddc":["576"],"file":[{"success":1,"access_level":"open_access","file_size":37019760,"relation":"main_file","date_created":"2024-11-07T10:59:29Z","checksum":"c32cf7bc75748d9c551d8eb70178bbec","file_id":"18519","creator":"psurendr","date_updated":"2024-11-07T10:59:29Z","file_name":"PhD_Thesis__Parvathy_071124_PDFA.pdf","content_type":"application/pdf"},{"date_updated":"2024-11-07T10:59:42Z","file_name":"PhD Thesis- Parvathy_071124.zip","content_type":"application/zip","creator":"psurendr","file_id":"18520","date_created":"2024-11-07T10:59:42Z","checksum":"4417e02d54084d89e75734e18caaa96d","access_level":"closed","relation":"source_file","file_size":41198857}],"_id":"18515","OA_place":"publisher","oa":1,"author":[{"last_name":"Surendranadh","full_name":"Surendranadh, Parvathy","id":"455235B8-F248-11E8-B48F-1D18A9856A87","first_name":"Parvathy","orcid":"0000-0001-6395-386X"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","acknowledgement":"I also acknowledge the funding agencies Marie Curie COFUND Doctoral Fellowship,\r\nAustrian Science Fund FWF (grant P32166) and ERC (grant PR1000ERC02) for financially\r\nsupporting my research over the years.","type":"dissertation","corr_author":"1","file_date_updated":"2024-11-07T10:59:42Z"},{"file":[{"file_name":"Thesis_Mojtaba Tavakoli_.docx","date_updated":"2024-12-20T10:31:37Z","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_id":"18699","creator":"mtavakol","date_created":"2024-12-20T10:23:17Z","checksum":"b61651d417cafddd740a8528f46068c5","access_level":"closed","relation":"source_file","file_size":118593521},{"access_level":"closed","file_size":63885521,"relation":"main_file","date_created":"2024-12-20T10:25:12Z","checksum":"c80bcfd1a34c23afc3538052325283e5","file_id":"18700","creator":"mtavakol","embargo_to":"open_access","file_name":"Thesis_Mojtaba Tavakoli_.pdf","date_updated":"2024-12-20T10:25:12Z","content_type":"application/pdf","embargo":"2026-08-01"}],"ddc":["600","570"],"page":"230","supervisor":[{"first_name":"Johann G","orcid":"0000-0001-8559-3973","last_name":"Danzl","id":"42EFD3B6-F248-11E8-B48F-1D18A9856A87","full_name":"Danzl, Johann G"}],"date_created":"2024-12-19T02:30:39Z","status":"public","has_accepted_license":"1","acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"},{"_id":"LifeSc"}],"language":[{"iso":"eng"}],"file_date_updated":"2024-12-20T10:31:37Z","corr_author":"1","type":"dissertation","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"last_name":"Tavakoli","full_name":"Tavakoli, Mojtaba","id":"3A0A06F4-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-7667-6854","first_name":"Mojtaba"}],"related_material":{"record":[{"status":"public","id":"11160","relation":"part_of_dissertation"},{"id":"18688","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"18677","status":"public"},{"relation":"part_of_dissertation","id":"18689","status":"public"}]},"OA_place":"publisher","_id":"18681","OA_embargo":"20","oa_version":"Published Version","day":"20","project":[{"grant_number":"26137","name":"Studying Organelle Structure and Function at Nanoscale Resolution with Expansion Microscopy","_id":"6285a163-2b32-11ec-9570-8e204ca2dba5"},{"grant_number":"W1232-B24","call_identifier":"FWF","name":"Molecular Drug Targets","_id":"26AA4EF2-B435-11E9-9278-68D0E5697425"}],"alternative_title":["ISTA Thesis"],"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png","short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)"},"month":"12","department":[{"_id":"GradSch"},{"_id":"JoDa"}],"date_updated":"2026-04-07T12:56:37Z","title":"Developing molecular and structural tools for studying brain architecture with super resolution expansion microscopy. LICONN: Molecularly-informed connectomics reconstruction with light microscopy","citation":{"ama":"Tavakoli M. Developing molecular and structural tools for studying brain architecture with super resolution expansion microscopy. LICONN: Molecularly-informed connectomics reconstruction with light microscopy. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18681\">10.15479/at:ista:18681</a>","chicago":"Tavakoli, Mojtaba. “Developing Molecular and Structural Tools for Studying Brain Architecture with Super Resolution Expansion Microscopy. LICONN: Molecularly-Informed Connectomics Reconstruction with Light Microscopy.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18681\">https://doi.org/10.15479/at:ista:18681</a>.","short":"M. Tavakoli, Developing Molecular and Structural Tools for Studying Brain Architecture with Super Resolution Expansion Microscopy. LICONN: Molecularly-Informed Connectomics Reconstruction with Light Microscopy, Institute of Science and Technology Austria, 2024.","apa":"Tavakoli, M. (2024). <i>Developing molecular and structural tools for studying brain architecture with super resolution expansion microscopy. LICONN: Molecularly-informed connectomics reconstruction with light microscopy</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18681\">https://doi.org/10.15479/at:ista:18681</a>","ieee":"M. Tavakoli, “Developing molecular and structural tools for studying brain architecture with super resolution expansion microscopy. LICONN: Molecularly-informed connectomics reconstruction with light microscopy,” Institute of Science and Technology Austria, 2024.","mla":"Tavakoli, Mojtaba. <i>Developing Molecular and Structural Tools for Studying Brain Architecture with Super Resolution Expansion Microscopy. LICONN: Molecularly-Informed Connectomics Reconstruction with Light Microscopy</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18681\">10.15479/at:ista:18681</a>.","ista":"Tavakoli M. 2024. Developing molecular and structural tools for studying brain architecture with super resolution expansion microscopy. LICONN: Molecularly-informed connectomics reconstruction with light microscopy. Institute of Science and Technology Austria."},"year":"2024","date_published":"2024-12-20T00:00:00Z","publication_status":"published","degree_awarded":"PhD","doi":"10.15479/at:ista:18681","article_processing_charge":"No","publication_identifier":{"isbn":["978-3-99078-048-0"],"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria"},{"publication_status":"published","degree_awarded":"PhD","article_processing_charge":"No","publication_identifier":{"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","doi":"10.15479/at:ista:15094","date_published":"2024-03-08T00:00:00Z","year":"2024","citation":{"ieee":"S. Cultrera di Montesano, “Persistence and Morse theory for discrete geometric structures,” Institute of Science and Technology Austria, 2024.","mla":"Cultrera di Montesano, Sebastiano. <i>Persistence and Morse Theory for Discrete Geometric Structures</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:15094\">10.15479/at:ista:15094</a>.","ista":"Cultrera di Montesano S. 2024. Persistence and Morse theory for discrete geometric structures. Institute of Science and Technology Austria.","ama":"Cultrera di Montesano S. Persistence and Morse theory for discrete geometric structures. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:15094\">10.15479/at:ista:15094</a>","chicago":"Cultrera di Montesano, Sebastiano. “Persistence and Morse Theory for Discrete Geometric Structures.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:15094\">https://doi.org/10.15479/at:ista:15094</a>.","short":"S. Cultrera di Montesano, Persistence and Morse Theory for Discrete Geometric Structures, Institute of Science and Technology Austria, 2024.","apa":"Cultrera di Montesano, S. (2024). <i>Persistence and Morse theory for discrete geometric structures</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:15094\">https://doi.org/10.15479/at:ista:15094</a>"},"title":"Persistence and Morse theory for discrete geometric structures","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"date_updated":"2026-04-07T12:58:48Z","department":[{"_id":"GradSch"},{"_id":"HeEd"}],"month":"03","project":[{"grant_number":"788183","call_identifier":"H2020","_id":"266A2E9E-B435-11E9-9278-68D0E5697425","name":"Alpha Shape Theory Extended"},{"call_identifier":"FWF","_id":"268116B8-B435-11E9-9278-68D0E5697425","name":"Mathematics, Computer Science","grant_number":"Z00342"},{"name":"Persistent Homology, Algorithms and Stochastic Geometry","_id":"0aa4bc98-070f-11eb-9043-e6fff9c6a316","grant_number":"I4887"},{"grant_number":"I02979-N35","_id":"2561EBF4-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","name":"Persistence and stability of geometric complexes"}],"alternative_title":["ISTA Thesis"],"day":"08","oa_version":"Published Version","ec_funded":1,"abstract":[{"text":"Point sets, geometric networks, and arrangements of hyperplanes are fundamental objects in\r\ndiscrete geometry that have captivated mathematicians for centuries, if not millennia. This\r\nthesis seeks to cast new light on these structures by illustrating specific instances where a\r\ntopological perspective, specifically through discrete Morse theory and persistent homology,\r\nprovides valuable insights.\r\n\r\nAt first glance, the topology of these geometric objects might seem uneventful: point sets\r\nessentially lack of topology, arrangements of hyperplanes are a decomposition of Rd, which\r\nis a contractible space, and the topology of a network primarily involves the enumeration\r\nof connected components and cycles within the network. However, beneath this apparent\r\nsimplicity, there lies an array of intriguing structures, a small subset of which will be uncovered\r\nin this thesis.\r\n\r\nFocused on three case studies, each addressing one of the mentioned objects, this work\r\nwill showcase connections that intertwine topology with diverse fields such as combinatorial\r\ngeometry, algorithms and data structures, and emerging applications like spatial biology.\r\n\r\n","lang":"eng"}],"_id":"15094","OA_place":"publisher","related_material":{"record":[{"relation":"part_of_dissertation","id":"15091","status":"public"},{"id":"11660","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"15090","status":"public"},{"id":"15093","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"13182","status":"public"},{"status":"public","id":"11658","relation":"part_of_dissertation"}]},"oa":1,"author":[{"id":"34D2A09C-F248-11E8-B48F-1D18A9856A87","full_name":"Cultrera di Montesano, Sebastiano","last_name":"Cultrera di Montesano","orcid":"0000-0001-6249-0832","first_name":"Sebastiano"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","type":"dissertation","file_date_updated":"2024-03-14T14:14:35Z","corr_author":"1","has_accepted_license":"1","language":[{"iso":"eng"}],"supervisor":[{"first_name":"Herbert","orcid":"0000-0002-9823-6833","last_name":"Edelsbrunner","full_name":"Edelsbrunner, Herbert","id":"3FB178DA-F248-11E8-B48F-1D18A9856A87"}],"status":"public","date_created":"2024-03-08T15:28:10Z","page":"108","file":[{"creator":"scultrer","file_id":"15112","content_type":"application/pdf","date_updated":"2024-03-14T08:55:07Z","file_name":"Thesis Sebastiano.pdf","file_size":4106872,"relation":"main_file","success":1,"access_level":"open_access","checksum":"1e468bfa42a7dcf04d89f4dadc621c87","date_created":"2024-03-14T08:55:07Z"},{"file_id":"15113","creator":"scultrer","date_updated":"2024-03-14T14:14:35Z","file_name":"Thesis (1).zip","content_type":"application/zip","access_level":"closed","relation":"source_file","file_size":4746234,"date_created":"2024-03-14T08:56:24Z","checksum":"bcbd213490f5a7e68855a092bbce93f1"}],"ddc":["514","500","516"]},{"has_accepted_license":"1","acknowledged_ssus":[{"_id":"EM-Fac"},{"_id":"LifeSc"},{"_id":"ScienComp"}],"language":[{"iso":"eng"}],"supervisor":[{"first_name":"Florian KM","orcid":"0000-0003-4790-8078","last_name":"Schur","id":"48AD8942-F248-11E8-B48F-1D18A9856A87","full_name":"Schur, Florian KM"}],"date_created":"2025-01-07T10:23:12Z","status":"public","keyword":["cryo-EM","cryo-ET","cryo-SPA","Structural Virology","Poxvirus","Vaccinia Virus","Structural Biology"],"page":"106","file":[{"relation":"source_file","file_size":38814932,"access_level":"closed","checksum":"3e51cab327c754045c3d29c1a50cc9a9","date_created":"2025-01-07T12:15:11Z","creator":"jstanger","file_id":"18769","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_name":"PhD_thesis_Julia_Datler.docx","date_updated":"2025-01-07T12:15:11Z"},{"date_updated":"2025-01-07T12:15:14Z","file_name":"PhD_thesis_Julia_Datler.pdf","content_type":"application/pdf","file_id":"18770","creator":"jstanger","date_created":"2025-01-07T12:15:14Z","checksum":"22fabe5b97950bf852212f6edb555173","access_level":"open_access","success":1,"relation":"main_file","file_size":12044865}],"ddc":["570"],"_id":"18766","OA_place":"publisher","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"12334"},{"relation":"part_of_dissertation","status":"public","id":"14979"}]},"oa":1,"author":[{"full_name":"Datler, Julia","id":"3B12E2E6-F248-11E8-B48F-1D18A9856A87","last_name":"Datler","orcid":"0000-0002-3616-8580","first_name":"Julia"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","acknowledgement":"This work was funded by the Austrian Science Fund (FWF) grant P31445 and ISTA. I\r\nwould like to express my gratitude to the Scientific Service Units, particularly the Lab\r\nSupport Facility, the Scientific Computing Facility and the Electron Microscopy Facility\r\nfor their tremendous support. I want to especially thank Alois for assisting me with the\r\ninstallation of countless new software and for troubleshooting cluster issues. A special\r\nthanks goes to Valentin for his outstanding support in cryo-EM data acquisition and\r\nhis ongoing help in improving the process to ensure that I obtained the best possible\r\ndata from my sample.","type":"dissertation","file_date_updated":"2025-01-07T12:15:14Z","corr_author":"1","project":[{"grant_number":"P31445","_id":"26736D6A-B435-11E9-9278-68D0E5697425","name":"Structural conservation and diversity in retroviral capsid","call_identifier":"FWF"}],"alternative_title":["ISTA thesis"],"day":"30","oa_version":"Published Version","abstract":[{"text":"Poxviruses are large pleomorphic double-stranded DNA viruses that include well known members such as variola virus, the causative agent of smallpox, Mpox virus, as well as Vaccinia virus (VACV), which serves as a vaccination strain for formerly mentioned viruses. VACV is a valuable model for studying large pleomorphic DNA viruses in general and poxviruses specifically, as many features, such as core morphology and structural proteins, are well conserved within this family. Despite decades of research, our understanding of the structural components and proteins that comprise the poxvirus core in mature virions remains limited. Although major core proteins were identified via indirect experimental evidence, the core's complexity, with its large size, structure and number of involved proteins, has hindered efforts to achieve high-resolution insights and to define the roles of the individual proteins. The specific protein composition of the core's individual layers, including the palisade layer and the inner core wall, has remained unclear. In this study, we have merged multiple approaches, including single particle cryo electron microscopy of purified virus cores, cryo-electron tomography and subtomogram averaging of mature virions and molecular modeling to elucidate the structural determinants of the VACV core. Due to the lack of experimentally derived structures, either in situ or reconstituted in vitro, we used Alphafold to predict models of the putative major core protein candidates, A10, 23k, A3, A4, and L4. Our results show that the VACV core is composed of several layers with varying local symmetries, forming more intricate interactions than observed previously. This allowed us to identify several molecular building blocks forming the viral core lattice. In particular, we identified trimers of protein A10 as a major core structure that forms the palisade layer of the viral core. Additionally, we revealed that six petals of a flower shaped core pore within the core wall are composed of A10 trimers. Furthermore, we obtained a cryo-EM density for the inner core wall that could potentially accommodate an A3 dimer. Integrating descriptions of protein interactions from previous studies enabled us to provide a detailed structural model of the poxvirus core wall, and our findings indicate that the interactions within A10 trimers are likely consistent across orthopox- and parapoxviruses. This combined application of cryo-SPA and cryo-ET can help overcome obstacles in studying complex virus structures in the future, including their key assembly proteins, interactions, and the formation into a core lattice. Our work provides important fundamental new insights into poxvirus core architecture, also considering the recent re-emergence of poxviruses.","lang":"eng"}],"publication_status":"published","degree_awarded":"PhD","article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-049-7"]},"doi":"10.15479/at:ista:18766","year":"2024","date_published":"2024-12-30T00:00:00Z","citation":{"apa":"Datler, J. (2024). <i>Elucidating the structural determinants of the poxvirus core using multi-modal cryo-EM</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18766\">https://doi.org/10.15479/at:ista:18766</a>","short":"J. Datler, Elucidating the Structural Determinants of the Poxvirus Core Using Multi-Modal Cryo-EM, Institute of Science and Technology Austria, 2024.","chicago":"Datler, Julia. “Elucidating the Structural Determinants of the Poxvirus Core Using Multi-Modal Cryo-EM.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18766\">https://doi.org/10.15479/at:ista:18766</a>.","ama":"Datler J. Elucidating the structural determinants of the poxvirus core using multi-modal cryo-EM. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18766\">10.15479/at:ista:18766</a>","ista":"Datler J. 2024. Elucidating the structural determinants of the poxvirus core using multi-modal cryo-EM. Institute of Science and Technology Austria.","mla":"Datler, Julia. <i>Elucidating the Structural Determinants of the Poxvirus Core Using Multi-Modal Cryo-EM</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18766\">10.15479/at:ista:18766</a>.","ieee":"J. Datler, “Elucidating the structural determinants of the poxvirus core using multi-modal cryo-EM,” Institute of Science and Technology Austria, 2024."},"title":"Elucidating the structural determinants of the poxvirus core using multi-modal cryo-EM","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png","short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)"},"date_updated":"2026-04-07T12:59:44Z","department":[{"_id":"GradSch"},{"_id":"FlSc"}],"month":"12"},{"type":"dissertation","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"first_name":"Michal","last_name":"Hledik","id":"4171253A-F248-11E8-B48F-1D18A9856A87","full_name":"Hledik, Michal"}],"file_date_updated":"2024-02-23T14:20:16Z","corr_author":"1","OA_place":"publisher","_id":"15020","oa":1,"related_material":{"record":[{"relation":"part_of_dissertation","id":"7606","status":"public"},{"id":"12081","status":"public","relation":"part_of_dissertation"},{"status":"public","id":"7553","relation":"part_of_dissertation"}]},"page":"158","file":[{"file_name":"hledik thesis pdfa 2b.pdf","date_updated":"2024-02-23T13:50:53Z","content_type":"application/pdf","file_id":"15021","creator":"mhledik","date_created":"2024-02-23T13:50:53Z","checksum":"b2d3da47c98d481577a4baf68944fe41","success":1,"access_level":"open_access","relation":"main_file","file_size":7102089},{"checksum":"eda9b9430da2610fee7ce1c1419a479a","date_created":"2024-02-23T13:50:54Z","relation":"source_file","file_size":14014790,"access_level":"closed","content_type":"application/zip","date_updated":"2024-02-23T14:20:16Z","file_name":"hledik thesis source.zip","file_id":"15022","creator":"mhledik"}],"ddc":["576","519"],"acknowledged_ssus":[{"_id":"ScienComp"}],"has_accepted_license":"1","language":[{"iso":"eng"}],"supervisor":[{"orcid":"0000-0002-8548-5240","first_name":"Nicholas H","id":"4880FE40-F248-11E8-B48F-1D18A9856A87","full_name":"Barton, Nicholas H","last_name":"Barton"},{"first_name":"Gašper","orcid":"0000-0002-6699-1455","last_name":"Tkačik","full_name":"Tkačik, Gašper","id":"3D494DCA-F248-11E8-B48F-1D18A9856A87"}],"status":"public","date_created":"2024-02-23T14:02:04Z","keyword":["Theoretical biology","Optimality","Evolution","Information"],"title":"Genetic information and biological optimization","department":[{"_id":"GradSch"},{"_id":"NiBa"},{"_id":"GaTk"}],"month":"02","date_updated":"2026-04-07T12:59:25Z","degree_awarded":"PhD","publication_status":"published","doi":"10.15479/at:ista:15020","publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","citation":{"ama":"Hledik M. Genetic information and biological optimization. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:15020\">10.15479/at:ista:15020</a>","chicago":"Hledik, Michal. “Genetic Information and Biological Optimization.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:15020\">https://doi.org/10.15479/at:ista:15020</a>.","short":"M. Hledik, Genetic Information and Biological Optimization, Institute of Science and Technology Austria, 2024.","apa":"Hledik, M. (2024). <i>Genetic information and biological optimization</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:15020\">https://doi.org/10.15479/at:ista:15020</a>","ieee":"M. Hledik, “Genetic information and biological optimization,” Institute of Science and Technology Austria, 2024.","mla":"Hledik, Michal. <i>Genetic Information and Biological Optimization</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:15020\">10.15479/at:ista:15020</a>.","ista":"Hledik M. 2024. Genetic information and biological optimization. Institute of Science and Technology Austria."},"date_published":"2024-02-23T00:00:00Z","year":"2024","abstract":[{"text":"This thesis consists of four distinct pieces of work within theoretical biology, with two themes in common: the concept of optimization in biological systems, and the use of information-theoretic tools to quantify biological stochasticity and statistical uncertainty.\r\nChapter 2 develops a statistical framework for studying biological systems which we believe to be optimized for a particular utility function, such as retinal neurons conveying information about visual stimuli. We formalize such beliefs as maximum-entropy Bayesian priors, constrained by the expected utility. We explore how such priors aid inference of system parameters with limited data and enable optimality hypothesis testing: is the utility higher than by chance?\r\nChapter 3 examines the ultimate biological optimization process: evolution by natural selection. As some individuals survive and reproduce more successfully than others, populations evolve towards fitter genotypes and phenotypes. We formalize this as accumulation of genetic information, and use population genetics theory to study how much such information can be accumulated per generation and maintained in the face of random mutation and genetic drift. We identify the population size and fitness variance as the key quantities that control information accumulation and maintenance.\r\nChapter 4 reuses the concept of genetic information from Chapter 3, but from a different perspective: we ask how much genetic information organisms actually need, in particular in the context of gene regulation. For example, how much information is needed to bind transcription factors at correct locations within the genome? Population genetics provides us with a refined answer: with an increasing population size, populations achieve higher fitness by maintaining more genetic information. Moreover, regulatory parameters experience selection pressure to optimize the fitness-information trade-off, i.e. minimize the information needed for a given fitness. This provides an evolutionary derivation of the optimization priors introduced in Chapter 2.\r\nChapter 5 proves an upper bound on mutual information between a signal and a communication channel output (such as neural activity). Mutual information is an important utility measure for biological systems, but its practical use can be difficult due to the large dimensionality of many biological channels. Sometimes, a lower bound on mutual information is computed by replacing the high-dimensional channel outputs with decodes (signal estimates). Our result provides a corresponding upper bound, provided that the decodes are the maximum posterior estimates of the signal.","lang":"eng"}],"project":[{"name":"International IST Doctoral Program","call_identifier":"H2020","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","grant_number":"665385"},{"_id":"2665AAFE-B435-11E9-9278-68D0E5697425","name":"Can evolution minimize spurious signaling crosstalk to reach optimal performance?","grant_number":"RGP0034/2018"},{"name":"Understanding the evolution of continuous genomes","_id":"bd6958e0-d553-11ed-ba76-86eba6a76c00","grant_number":"101055327"}],"alternative_title":["ISTA Thesis"],"oa_version":"Published Version","day":"23","ec_funded":1},{"ec_funded":1,"day":"20","oa_version":"Published Version","alternative_title":["ISTA Thesis"],"project":[{"grant_number":"665385","call_identifier":"H2020","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","name":"International IST Doctoral Program"}],"abstract":[{"text":"Locomotion is ubiquitous in the animal kingdom because an animal's survival depends on its ability to navigate its environment to find food, avoid predators and locate potential mates. These behaviours require control mechanisms that can extract information from the environment, particularly visual cues. Selective evolutionary pressures have thus refined such visuomotor transformations in a species-specific manner to meet the specific ecological and ethological challenges of each organism. However, a common challenge across organisms as visual information processing\r\nbecomes increasingly detailed is the mechanisms required to synthesise disparate pieces of information into a coherent percept or unified picture of the world. In this thesis, I investigate how disparate visual information is combined in the brain of Drosophila melanogaster to effectively guide locomotion.\r\nFor this, I first designed and built a behavioural setup to record locomotion and present visual stimuli to freely-walking fruit flies in a closed-loop manner. This setup allowed the investigation of innate visually-guided behaviours, including the optomotor reflex and courtship.\r\nSecond, taking advantage of my system I investigated the optomotor response, a reflexive visual stabilisation behaviour in which flies turn in the direction of global motion to minimise retinal slip. This behaviour is thought to be mediated by Lobula plate tangential cells (LPTCs); a complex network of optic-flow-sensitive neurons essential for self-motion estimation. Using a novel genetic mutant, I demonstrate that electrical coupling between two LPTC subtypes, contralateral HS and H2 neurons, regulates the balance between smooth optomotor turning and saccadic anti-optomotor responses. These findings underscore the critical role of binocular motion cue integration in guiding course control. Finally, I developed a novel behavioural paradigm in which a sexually aroused male fruit fly is presented with an optomotor distractor. This setup creates competition between two visual behaviours, courtship tracking and the  optomotor response, enabling me to explore how the visual system resolves this conflict. In this setting, males\r\nengaged in courtship selectively suppress their optomotor response based on the female's location. Furthermore, when this experiment is replicated with an “artificial female”, optogenetically aroused males alternate between tracking and optomotor responses. The probability and dynamics of this switching are determined by the relative strengths of the two competing stimuli. In summary, the results presented in this thesis explore two mechanisms – integration and competition - through which visual information is combined in the brain of the fruit fly to drive locomotion.","lang":"eng"}],"date_published":"2024-11-20T00:00:00Z","year":"2024","citation":{"chicago":"Satapathy, Roshan K. “Mechanisms of Visual Integration and Competition in Innate Behaviours in Drosophila Melanogaster.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18568\">https://doi.org/10.15479/at:ista:18568</a>.","ama":"Satapathy RK. Mechanisms of visual integration and competition in innate behaviours in Drosophila melanogaster. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18568\">10.15479/at:ista:18568</a>","apa":"Satapathy, R. K. (2024). <i>Mechanisms of visual integration and competition in innate behaviours in Drosophila melanogaster</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18568\">https://doi.org/10.15479/at:ista:18568</a>","short":"R.K. Satapathy, Mechanisms of Visual Integration and Competition in Innate Behaviours in Drosophila Melanogaster, Institute of Science and Technology Austria, 2024.","mla":"Satapathy, Roshan K. <i>Mechanisms of Visual Integration and Competition in Innate Behaviours in Drosophila Melanogaster</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18568\">10.15479/at:ista:18568</a>.","ieee":"R. K. Satapathy, “Mechanisms of visual integration and competition in innate behaviours in Drosophila melanogaster,” Institute of Science and Technology Austria, 2024.","ista":"Satapathy RK. 2024. Mechanisms of visual integration and competition in innate behaviours in Drosophila melanogaster. Institute of Science and Technology Austria."},"publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-047-3"]},"publisher":"Institute of Science and Technology Austria","article_processing_charge":"No","doi":"10.15479/at:ista:18568","degree_awarded":"PhD","publication_status":"published","date_updated":"2026-04-07T13:00:36Z","department":[{"_id":"GradSch"},{"_id":"MaJö"}],"month":"11","license":"https://creativecommons.org/licenses/by-sa/4.0/","tmp":{"image":"/images/cc_by_sa.png","legal_code_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","short":"CC BY-SA (4.0)","name":"Creative Commons Attribution-ShareAlike 4.0 International Public License (CC BY-SA 4.0)"},"title":"Mechanisms of visual integration and competition in innate behaviours in Drosophila melanogaster","status":"public","date_created":"2024-11-19T12:34:30Z","supervisor":[{"full_name":"Jösch, Maximilian A","id":"2BD278E6-F248-11E8-B48F-1D18A9856A87","last_name":"Jösch","first_name":"Maximilian A","orcid":"0000-0002-3937-1330"}],"language":[{"iso":"eng"}],"acknowledged_ssus":[{"_id":"M-Shop"}],"has_accepted_license":"1","ddc":["573"],"file":[{"relation":"main_file","file_size":10960975,"success":1,"access_level":"open_access","checksum":"340f2bfe882c8a85e11ec0687ca15f5e","date_created":"2024-11-19T12:39:55Z","creator":"rsatapat","file_id":"18570","content_type":"application/pdf","date_updated":"2024-11-19T12:39:55Z","file_name":"Roshan PhD thesis-Final.pdf"},{"relation":"source_file","file_size":36695917,"access_level":"closed","checksum":"0f846fce60d6ea511e07f77eff59a6a1","date_created":"2024-11-19T12:46:47Z","creator":"rsatapat","file_id":"18571","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","date_updated":"2024-12-13T10:27:25Z","file_name":"Roshan PhD thesis-Final.docx"}],"page":"114","oa":1,"related_material":{"record":[{"id":"18444","status":"public","relation":"part_of_dissertation"}]},"_id":"18568","OA_place":"publisher","corr_author":"1","file_date_updated":"2024-12-13T10:27:25Z","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","author":[{"full_name":"Satapathy, Roshan K","id":"46046B7A-F248-11E8-B48F-1D18A9856A87","last_name":"Satapathy","orcid":"0009-0006-2974-5075","first_name":"Roshan K"}],"acknowledgement":"I am incredibly thankful for the outstanding support provided by ISTA, especially the Machine Shop team, who made conducting research much easier and more efficient. I am also grateful for the funding provided by European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie programme (665385) and The German Research Foundation grant DFG (SPP2205) “Evolutionary optimization of neuronal processing”.","type":"dissertation"},{"OA_place":"publisher","_id":"17336","oa":1,"related_material":{"record":[{"relation":"part_of_dissertation","id":"17351","status":"public"},{"status":"public","id":"17353","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"17350"},{"relation":"part_of_dissertation","status":"public","id":"17352"},{"relation":"part_of_dissertation","id":"17143","status":"public"}]},"type":"dissertation","author":[{"first_name":"Francesco","id":"d3ac8ac6-dc8d-11ea-abe3-e2a9628c4c3c","full_name":"Pedrotti, Francesco","last_name":"Pedrotti"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","file_date_updated":"2024-08-02T09:27:15Z","corr_author":"1","has_accepted_license":"1","language":[{"iso":"eng"}],"supervisor":[{"orcid":"0000-0002-0845-1338","first_name":"Jan","full_name":"Maas, Jan","id":"4C5696CE-F248-11E8-B48F-1D18A9856A87","last_name":"Maas"}],"status":"public","date_created":"2024-07-29T09:14:14Z","page":"183","file":[{"creator":"fpedrott","file_id":"17366","content_type":"application/pdf","date_updated":"2024-08-02T09:23:26Z","file_name":"thesis_final.pdf","file_size":2941599,"relation":"main_file","success":1,"access_level":"open_access","checksum":"11650bab714ef85ad43a287060850523","date_created":"2024-08-02T09:23:26Z"},{"content_type":"application/x-zip-compressed","file_name":"thesis_final_source.zip","date_updated":"2024-08-02T09:27:15Z","file_id":"17367","creator":"fpedrott","checksum":"c30ba5611941226cf1bfc867c25b1e80","date_created":"2024-08-02T09:27:15Z","relation":"source_file","file_size":6293375,"access_level":"closed"}],"ddc":["500","510","515","519"],"degree_awarded":"PhD","publication_status":"published","doi":"10.15479/at:ista:17336","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","citation":{"ista":"Pedrotti F. 2024. Functional inequalities and convergence of stochastic processes. Institute of Science and Technology Austria.","mla":"Pedrotti, Francesco. <i>Functional Inequalities and Convergence of Stochastic Processes</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17336\">10.15479/at:ista:17336</a>.","ieee":"F. Pedrotti, “Functional inequalities and convergence of stochastic processes,” Institute of Science and Technology Austria, 2024.","apa":"Pedrotti, F. (2024). <i>Functional inequalities and convergence of stochastic processes</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17336\">https://doi.org/10.15479/at:ista:17336</a>","short":"F. Pedrotti, Functional Inequalities and Convergence of Stochastic Processes, Institute of Science and Technology Austria, 2024.","chicago":"Pedrotti, Francesco. “Functional Inequalities and Convergence of Stochastic Processes.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17336\">https://doi.org/10.15479/at:ista:17336</a>.","ama":"Pedrotti F. Functional inequalities and convergence of stochastic processes. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17336\">10.15479/at:ista:17336</a>"},"date_published":"2024-07-31T00:00:00Z","year":"2024","title":"Functional inequalities and convergence of stochastic processes","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode","image":"/images/cc_by_nc_nd.png","short":"CC BY-NC-ND (4.0)","name":"Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)"},"department":[{"_id":"GradSch"},{"_id":"JaMa"}],"month":"07","date_updated":"2026-04-07T13:00:03Z","project":[{"grant_number":"716117","_id":"256E75B8-B435-11E9-9278-68D0E5697425","name":"Optimal Transport and Stochastic Dynamics","call_identifier":"H2020"},{"name":"Taming Complexity in Partial Differential Systems","_id":"fc31cba2-9c52-11eb-aca3-ff467d239cd2","grant_number":"F6504"}],"alternative_title":["ISTA Thesis"],"oa_version":"Published Version","day":"31","ec_funded":1,"abstract":[{"lang":"eng","text":"This thesis deals with the study of stochastic processes and their ergodicity properties. The\r\nvariety of problems encountered calls for a set of different approaches, ranging from classical to\r\nmodern ones: a special place is held by probabilistic methods based on couplings, by functional\r\ninequalities, and by the theory of gradient flows in the space of measures.\r\n\r\nThe material is organized as follows. Chapter 1 contains the introduction to this thesis, starting\r\nwith a general presentation of some of the relevant topics. Section 1.1 is dedicated to the\r\ntheory of gradient flows in metric spaces, and introduces the first contribution of this thesis\r\n[DSMP24], which is presented in detail in Chapter 2. Section 1.2 moves to the topic of\r\ncurvature of Markov chains, concluding with a brief description of our second contribution\r\n[Ped23], which is included in Chapter 3. Section 1.3 discusses applications of stochastic\r\nprocesses to the theory of sampling, in particular the recent framework of score-based diffusion\r\nmodels, and our contribution [PMM24], which is contained in Chapter 4. Section 1.4 discusses\r\nsome related problems, concerning the regularization properties of the heat flow. It serves\r\nas a motivation for the work [BP24], which we report in Chapter 5. Finally, Section 1.5\r\ndiscusses the last contribution of this thesis, which can be found in Chapter 6. It deals with\r\nthe convergence to equilibrium of a particular stochastic model from quantitative genetics:\r\nthis is established via some functional inequalities, which we prove with probabilistic arguments\r\nbased on couplings.\r\n"}]},{"ec_funded":1,"day":"18","oa_version":"Published Version","alternative_title":["ISTA Thesis"],"project":[{"call_identifier":"H2020","name":"International IST Doctoral Program","_id":"2564DBCA-B435-11E9-9278-68D0E5697425","grant_number":"665385"}],"abstract":[{"text":"Instant messaging applications like Whatsapp, Signal or Telegram have become ubiquitous in today's society.\r\nMany of them provide not only end-to-end encryption, but also security guarantees even when the key material gets compromised.\r\nThese are achieved through frequent key update performed by users.\r\nIn particular, the compromise of a group key should preserve confidentiality of previously exchanged messages (forward secrecy), and a subsequent key update will ensure security for future ones (post-compromise security).\r\nThough great protocols for one-on-one communication have been known for some time, the design of ones that scale efficiently for larger groups while achieving akin security guarantees is a hard problem.\r\nA great deal of research has been aimed at this topic, much of it under the umbrella of the Messaging Layer Security (MLS) working group at the IETF. \r\nStarted in 2018, this joint effort by academics and industry culminated in 2023 with the publication of the first standard for secure group messaging [IETF, RFC9420].\r\n\r\nAt the core of secure group messaging is a cryptographic primitive termed Continuous Group Key Agreement, or CGKA [Alwen et al. 2021], that essentially allows a changing group of users to agree on a common key with the added functionality security against compromises is achieved by users asynchronously issuing a key update. In this thesis we contribute to the understanding of CGKA across different angles.\r\nFirst, we present a new technique to effect dynamic operations in groups, i.e., add or remove members, that can be more efficient that the one employed by MLS in certain settings.\r\nConsidering the setting of users belonging to multiple overlapping groups, we then show lowerbounds on the communication cost of constructions that leverage said overlap, at the same time showing protocols that are asymptotically optimal and efficient for practical settings, respectively. Along the way, we show that the communication cost of key updates in MLS is average-cost optimal.\r\nAn important feature in CGKA protocols, particularly for big groups, is the possibility of executing several group operations concurrently. While later versions of MLS support this, they do at the cost of worsening the communication efficiency of future group operations.\r\nIn this thesis we introduce two new protocols that permit concurrency without any negative effect on efficiency. Our protocols circumvent previously existing lower bounds by satisfying a new notion of post-compromise security that only asks for security to be re-established after a certain number of key updates have taken place. While this can be slower than MLS in terms of rounds of communication, we show that it leads to more efficient overall communication. \r\nAdditionally, we introduce a new technique that allows group members to decrease the information they need to store and download, which makes one of our protocols enjoy much lower download cost than any other existing CGKA constructions. ","lang":"eng"}],"citation":{"mla":"Pascual Perez, Guillermo. <i>On the Efficiency and Security of Secure Group Messaging</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18088\">10.15479/at:ista:18088</a>.","ieee":"G. Pascual Perez, “On the efficiency and security of secure group messaging,” Institute of Science and Technology Austria, 2024.","ista":"Pascual Perez G. 2024. On the efficiency and security of secure group messaging. Institute of Science and Technology Austria.","chicago":"Pascual Perez, Guillermo. “On the Efficiency and Security of Secure Group Messaging.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18088\">https://doi.org/10.15479/at:ista:18088</a>.","ama":"Pascual Perez G. On the efficiency and security of secure group messaging. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18088\">10.15479/at:ista:18088</a>","apa":"Pascual Perez, G. (2024). <i>On the efficiency and security of secure group messaging</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18088\">https://doi.org/10.15479/at:ista:18088</a>","short":"G. Pascual Perez, On the Efficiency and Security of Secure Group Messaging, Institute of Science and Technology Austria, 2024."},"year":"2024","date_published":"2024-09-18T00:00:00Z","doi":"10.15479/at:ista:18088","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","degree_awarded":"PhD","publication_status":"published","department":[{"_id":"KrPi"},{"_id":"GradSch"}],"month":"09","date_updated":"2026-04-07T13:01:26Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"title":"On the efficiency and security of secure group messaging","date_created":"2024-09-18T12:59:49Z","status":"public","supervisor":[{"first_name":"Krzysztof Z","orcid":"0000-0002-9139-1654","last_name":"Pietrzak","full_name":"Pietrzak, Krzysztof Z","id":"3E04A7AA-F248-11E8-B48F-1D18A9856A87"}],"language":[{"iso":"eng"}],"has_accepted_license":"1","ddc":["000"],"file":[{"access_level":"closed","relation":"source_file","file_size":11917734,"date_created":"2024-09-19T12:35:38Z","checksum":"ce0dca715b3df48e52e2e891b6ac1bc5","file_id":"18099","creator":"gpascual","file_name":"thesis_bundle.zip","date_updated":"2024-09-19T12:35:38Z","content_type":"application/x-zip-compressed"},{"access_level":"open_access","file_size":2729427,"relation":"main_file","date_created":"2024-09-19T12:36:08Z","checksum":"4a2c72e90f1a0ef2a13cff800f8d1265","creator":"gpascual","file_id":"18100","date_updated":"2024-09-19T12:36:08Z","file_name":"thesis_gpasper.pdf","content_type":"application/pdf"}],"page":"239","related_material":{"record":[{"relation":"part_of_dissertation","status":"public","id":"10408"},{"id":"11476","status":"public","relation":"part_of_dissertation"},{"status":"public","id":"18086","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"10049","status":"public"}]},"oa":1,"OA_place":"publisher","_id":"18088","corr_author":"1","file_date_updated":"2024-09-19T12:36:08Z","type":"dissertation","author":[{"first_name":"Guillermo","orcid":"0000-0001-8630-415X","last_name":"Pascual Perez","full_name":"Pascual Perez, Guillermo","id":"2D7ABD02-F248-11E8-B48F-1D18A9856A87"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd"},{"corr_author":"1","file_date_updated":"2024-09-04T08:36:06Z","author":[{"first_name":"Ilia","last_name":"Markov","full_name":"Markov, Ilia","id":"D0CF4148-C985-11E9-8066-0BDEE5697425"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","type":"dissertation","oa":1,"related_material":{"record":[{"id":"17456","status":"public","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","status":"public","id":"14461"},{"relation":"part_of_dissertation","id":"12780","status":"public"}]},"_id":"17490","OA_place":"publisher","ddc":["000"],"file":[{"relation":"source_file","file_size":43327753,"access_level":"closed","checksum":"77609f4835d2730e46fa0d42d9134ed9","date_created":"2024-09-04T08:35:35Z","creator":"imarkov","file_id":"17491","content_type":"application/x-zip-compressed","date_updated":"2024-09-04T08:35:35Z","file_name":"Thesis.zip"},{"creator":"imarkov","file_id":"17492","content_type":"application/pdf","file_name":"Thesis_final_version_pdfa2.pdf","date_updated":"2024-09-04T08:36:06Z","relation":"main_file","file_size":2756082,"access_level":"open_access","success":1,"checksum":"9e68f7217570f756ceb8f70b980938cd","date_created":"2024-09-04T08:36:06Z"}],"page":"102","date_created":"2024-09-04T08:51:11Z","status":"public","supervisor":[{"id":"4A899BFC-F248-11E8-B48F-1D18A9856A87","full_name":"Alistarh, Dan-Adrian","last_name":"Alistarh","first_name":"Dan-Adrian","orcid":"0000-0003-3650-940X"}],"language":[{"iso":"eng"}],"has_accepted_license":"1","acknowledged_ssus":[{"_id":"ScienComp"}],"date_updated":"2026-04-07T13:00:54Z","department":[{"_id":"GradSch"},{"_id":"DaAl"}],"month":"09","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"title":"Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective","year":"2024","date_published":"2024-09-04T00:00:00Z","citation":{"ista":"Markov I. 2024. Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective. Institute of Science and Technology Austria.","mla":"Markov, Ilia. <i>Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17490\">10.15479/at:ista:17490</a>.","ieee":"I. Markov, “Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective,” Institute of Science and Technology Austria, 2024.","apa":"Markov, I. (2024). <i>Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17490\">https://doi.org/10.15479/at:ista:17490</a>","short":"I. Markov, Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective, Institute of Science and Technology Austria, 2024.","chicago":"Markov, Ilia. “Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17490\">https://doi.org/10.15479/at:ista:17490</a>.","ama":"Markov I. Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17490\">10.15479/at:ista:17490</a>"},"article_processing_charge":"No","publication_identifier":{"issn":["2663-337X"]},"publisher":"Institute of Science and Technology Austria","doi":"10.15479/at:ista:17490","degree_awarded":"PhD","publication_status":"published","abstract":[{"lang":"eng","text":"Deep learning is essential in numerous applications nowadays, with many recent advancements made possible by training very large models. Despite their broad applicability, training neural networks is often time-intensive, and it is usually impractical to manage large models and datasets on a single machine. To address these issues, distributed deep learning training has become increasingly important. However, distributed training requires synchronization among nodes, and the mini-batch stochastic gradient descent algorithm places a significant load on network connections. A possible solution to tackle the synchronization bottleneck is to reduce a message size by lossy compression.\r\n\r\nIn this thesis, we investigate systems and algorithmic approaches to communication compression during training. From the systems perspective, we demonstrate that a common approach of expensive hardware overprovisioning can be replaced through a thorough system design. We introduce a framework that introduces efficient software support for compressed communication in machine learning applications, applicable to both multi-GPU single-node training and larger-scale multi-node training. Our framework integrates with popular ML frameworks, providing up to 3x speedups for multi-GPU nodes based on commodity hardware and order-of-magnitude improvements in the multi-node setting, with negligible impact on accuracy.\r\n\r\nAlso, we consider an application of our framework to different communication schemes, such as Fully Sharded Data Parallel. We provide strong convergence guarantees for the compression in such a setup. Empirical validation shows that our method preserves model accuracy for GPT-family models with up to 1.3 billion parameters, while completely removing the communication bottlenecks of non-compressed alternatives, providing up to 2.2x speedups end-to-end.\r\n\r\nFrom the algorithmic side, we propose a general framework that dynamically adjusts the degree of compression across a model's layers during training. This approach enhances overall compression and results in significant speedups without compromising accuracy. Our algorithm utilizes an adaptive algorithm that automatically selects the optimal compression parameters for model layers, ensuring the best compression ratio while adhering to an error constraint. Our method is effective across all existing families of compression methods. It achieves up to 2.5x faster training and up to a 5x improvement in compression compared to efficient implementations of current approaches. Additionally, LGreCo can complement existing adaptive algorithms.\r\n"}],"ec_funded":1,"oa_version":"Published Version","day":"04","alternative_title":["ISTA Thesis"],"project":[{"call_identifier":"H2020","_id":"268A44D6-B435-11E9-9278-68D0E5697425","name":"Elastic Coordination for Scalable Machine Learning","grant_number":"805223"}]},{"date_created":"2024-09-18T11:35:14Z","status":"public","language":[{"iso":"eng"}],"publication":"Security and Cryptography for Networks: 14th International Conference","page":"294–313","intvolume":"     14974","editor":[{"first_name":"Clemente","full_name":"Galdi, Clemente","last_name":"Galdi"},{"first_name":"Duong Hieu","last_name":"Phan","full_name":"Phan, Duong Hieu"}],"related_material":{"record":[{"relation":"dissertation_contains","id":"18088","status":"public"}]},"_id":"18086","place":"Cham","corr_author":"1","type":"conference","author":[{"last_name":"Alwen","full_name":"Alwen, Joel F","id":"2A8DFA8C-F248-11E8-B48F-1D18A9856A87","first_name":"Joel F"},{"first_name":"Benedikt","orcid":"0000-0002-7553-6606","last_name":"Auerbach","full_name":"Auerbach, Benedikt","id":"D33D2B18-E445-11E9-ABB7-15F4E5697425"},{"first_name":"Miguel","orcid":"0000-0002-2505-4246","full_name":"Cueto Noval, Miguel","id":"ffc563a3-f6e0-11ea-865d-e3cce03d17cc","last_name":"Cueto Noval"},{"id":"3E83A2F8-F248-11E8-B48F-1D18A9856A87","full_name":"Klein, Karen","last_name":"Klein","first_name":"Karen"},{"id":"2D7ABD02-F248-11E8-B48F-1D18A9856A87","full_name":"Pascual Perez, Guillermo","last_name":"Pascual Perez","first_name":"Guillermo","orcid":"0000-0001-8630-415X"},{"orcid":"0000-0002-9139-1654","first_name":"Krzysztof Z","id":"3E04A7AA-F248-11E8-B48F-1D18A9856A87","full_name":"Pietrzak, Krzysztof Z","last_name":"Pietrzak"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","oa_version":"None","day":"10","volume":14974,"external_id":{"isi":["001330408000014"]},"quality_controlled":"1","alternative_title":["LNCS"],"abstract":[{"lang":"eng","text":"Abstract. Continuous group key agreement (CGKA) allows a group of\r\nusers to maintain a continuously updated shared key in an asynchronous\r\nsetting where parties only come online sporadically and their messages\r\nare relayed by an untrusted server. CGKA captures the basic primitive\r\nunderlying group messaging schemes.\r\nCurrent solutions including TreeKEM (“Messaging Layer Security”\r\n(MLS) IETF RFC 9420) cannot handle concurrent requests while retaining low communication complexity. The exception being CoCoA, which\r\nis concurrent while having extremely low communication complexity (in\r\ngroups of size n and for m concurrent updates the communication per\r\nuser is log(n), i.e., independent of m). The main downside of CoCoA\r\nis that in groups of size n, users might have to do up to log(n) update\r\nrequests to the server to ensure their (potentially corrupted) key material has been refreshed.\r\nIn this work we present a “fast healing” concurrent CGKA protocol,\r\nnamed DeCAF, where users will heal after at most log(t) requests, with\r\nt being the number of corrupted users. While also suitable for the standard central-server setting, our protocol is particularly interesting for\r\nrealizing decentralized group messaging, where protocol messages (add,\r\nremove, update) are being posted on some append-only data structure\r\nrather than sent to a server. In this setting, concurrency is crucial once\r\nthe rate of requests exceeds, say, the rate at which new blocks are added\r\nto a blockchain.\r\nIn the central-server setting, CoCoA (the only alternative with concurrency, sub-linear communication and basic post-compromise security)\r\nenjoys much lower download communication. However, in the decentralized setting – where there is no server which can craft specific messages\r\nfor different users to reduce their download communication – our protocol\r\nsignificantly outperforms CoCoA. DeCAF heals in fewer epochs (log(t)\r\nvs. log(n)) while incurring a similar per epoch per user communication\r\ncost."}],"conference":{"start_date":"2024-09-11","location":"Amalfi, Italy","name":"SCN: Security and Cryptography for Networks","end_date":"2024-09-13"},"citation":{"short":"J.F. Alwen, B. Auerbach, M. Cueto Noval, K. Klein, G. Pascual Perez, K.Z. Pietrzak, in:, C. Galdi, D.H. Phan (Eds.), Security and Cryptography for Networks: 14th International Conference, Springer Nature, Cham, 2024, pp. 294–313.","apa":"Alwen, J. F., Auerbach, B., Cueto Noval, M., Klein, K., Pascual Perez, G., &#38; Pietrzak, K. Z. (2024). DeCAF: Decentralizable CGKA with fast healing. In C. Galdi &#38; D. H. Phan (Eds.), <i>Security and Cryptography for Networks: 14th International Conference</i> (Vol. 14974, pp. 294–313). Cham: Springer Nature. <a href=\"https://doi.org/10.1007/978-3-031-71073-5_14\">https://doi.org/10.1007/978-3-031-71073-5_14</a>","ama":"Alwen JF, Auerbach B, Cueto Noval M, Klein K, Pascual Perez G, Pietrzak KZ. DeCAF: Decentralizable CGKA with fast healing. In: Galdi C, Phan DH, eds. <i>Security and Cryptography for Networks: 14th International Conference</i>. Vol 14974. Cham: Springer Nature; 2024:294–313. doi:<a href=\"https://doi.org/10.1007/978-3-031-71073-5_14\">10.1007/978-3-031-71073-5_14</a>","chicago":"Alwen, Joel F, Benedikt Auerbach, Miguel Cueto Noval, Karen Klein, Guillermo Pascual Perez, and Krzysztof Z Pietrzak. “DeCAF: Decentralizable CGKA with Fast Healing.” In <i>Security and Cryptography for Networks: 14th International Conference</i>, edited by Clemente Galdi and Duong Hieu Phan, 14974:294–313. Cham: Springer Nature, 2024. <a href=\"https://doi.org/10.1007/978-3-031-71073-5_14\">https://doi.org/10.1007/978-3-031-71073-5_14</a>.","ista":"Alwen JF, Auerbach B, Cueto Noval M, Klein K, Pascual Perez G, Pietrzak KZ. 2024. DeCAF: Decentralizable CGKA with fast healing. Security and Cryptography for Networks: 14th International Conference. SCN: Security and Cryptography for Networks, LNCS, vol. 14974, 294–313.","ieee":"J. F. Alwen, B. Auerbach, M. Cueto Noval, K. Klein, G. Pascual Perez, and K. Z. Pietrzak, “DeCAF: Decentralizable CGKA with fast healing,” in <i>Security and Cryptography for Networks: 14th International Conference</i>, Amalfi, Italy, 2024, vol. 14974, pp. 294–313.","mla":"Alwen, Joel F., et al. “DeCAF: Decentralizable CGKA with Fast Healing.” <i>Security and Cryptography for Networks: 14th International Conference</i>, edited by Clemente Galdi and Duong Hieu Phan, vol. 14974, Springer Nature, 2024, pp. 294–313, doi:<a href=\"https://doi.org/10.1007/978-3-031-71073-5_14\">10.1007/978-3-031-71073-5_14</a>."},"date_published":"2024-09-10T00:00:00Z","year":"2024","publication_status":"published","doi":"10.1007/978-3-031-71073-5_14","publisher":"Springer Nature","publication_identifier":{"isbn":["9783031710728"],"issn":["0302-9743"],"eisbn":["9783031710735"],"eissn":["1611-3349"]},"article_processing_charge":"No","department":[{"_id":"GradSch"},{"_id":"KrPi"}],"month":"09","date_updated":"2026-04-07T13:01:26Z","title":"DeCAF: Decentralizable CGKA with fast healing","isi":1},{"status":"public","date_created":"2023-11-15T23:48:14Z","scopus_import":"1","language":[{"iso":"eng"}],"publication":"Reviews in Mathematical Physics","has_accepted_license":"1","ddc":["510"],"file":[{"file_id":"18786","creator":"dernst","file_name":"2024_ReviewsmathPhysics_Henheik.pdf","date_updated":"2025-01-09T07:56:28Z","content_type":"application/pdf","access_level":"open_access","success":1,"file_size":503910,"relation":"main_file","date_created":"2025-01-09T07:56:28Z","checksum":"2b053a4223b4db14b90520999ec56054"}],"intvolume":"        36","related_material":{"record":[{"id":"19540","status":"public","relation":"dissertation_contains"},{"status":"public","id":"18135","relation":"dissertation_contains"}]},"oa":1,"arxiv":1,"OA_place":"publisher","_id":"14542","issue":"9","corr_author":"1","file_date_updated":"2025-01-09T07:56:28Z","type":"journal_article","author":[{"orcid":"0000-0003-1106-327X","first_name":"Sven Joscha","full_name":"Henheik, Sven Joscha","id":"31d731d7-d235-11ea-ad11-b50331c8d7fb","last_name":"Henheik"},{"orcid":"0000-0003-4476-2288","first_name":"Asbjørn Bækgaard","id":"e1a2682f-dc8d-11ea-abe3-81da9ac728f1","full_name":"Lauritsen, Asbjørn Bækgaard","last_name":"Lauritsen"},{"full_name":"Roos, Barbara","id":"5DA90512-D80F-11E9-8994-2E2EE6697425","last_name":"Roos","first_name":"Barbara","orcid":"0000-0002-9071-5880"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"We thank Robert Seiringer for comments on the paper. J. H. gratefully acknowledges  partial  financial  support  by  the  ERC  Advanced  Grant  “RMTBeyond”No. 101020331.This research was funded in part by the Austrian Science Fund (FWF) grantnumber I6427.","ec_funded":1,"oa_version":"Published Version","day":"01","volume":36,"project":[{"call_identifier":"H2020","name":"Random matrices beyond Wigner-Dyson-Mehta","_id":"62796744-2b32-11ec-9570-940b20777f1d","grant_number":"101020331"},{"grant_number":"I06427","_id":"bda63fe5-d553-11ed-ba76-a16e3d2f256b","name":"Mathematical Challenges in BCS Theory of Superconductivity"}],"external_id":{"arxiv":["2301.05621"],"isi":["001099640300002"]},"quality_controlled":"1","article_type":"original","abstract":[{"lang":"eng","text":"It is a remarkable property of BCS theory that the ratio of the energy gap at zero temperature Ξ\r\n and the critical temperature Tc is (approximately) given by a universal constant, independent of the microscopic details of the fermionic interaction. This universality has rigorously been proven quite recently in three spatial dimensions and three different limiting regimes: weak coupling, low density and high density. The goal of this short note is to extend the universal behavior to lower dimensions d=1,2 and give an exemplary proof in the weak coupling limit."}],"OA_type":"hybrid","citation":{"chicago":"Henheik, Sven Joscha, Asbjørn Bækgaard Lauritsen, and Barbara Roos. “Universality in Low-Dimensional BCS Theory.” <i>Reviews in Mathematical Physics</i>. World Scientific Publishing, 2024. <a href=\"https://doi.org/10.1142/s0129055x2360005x\">https://doi.org/10.1142/s0129055x2360005x</a>.","ama":"Henheik SJ, Lauritsen AB, Roos B. Universality in low-dimensional BCS theory. <i>Reviews in Mathematical Physics</i>. 2024;36(9). doi:<a href=\"https://doi.org/10.1142/s0129055x2360005x\">10.1142/s0129055x2360005x</a>","apa":"Henheik, S. J., Lauritsen, A. B., &#38; Roos, B. (2024). Universality in low-dimensional BCS theory. <i>Reviews in Mathematical Physics</i>. World Scientific Publishing. <a href=\"https://doi.org/10.1142/s0129055x2360005x\">https://doi.org/10.1142/s0129055x2360005x</a>","short":"S.J. Henheik, A.B. Lauritsen, B. Roos, Reviews in Mathematical Physics 36 (2024).","mla":"Henheik, Sven Joscha, et al. “Universality in Low-Dimensional BCS Theory.” <i>Reviews in Mathematical Physics</i>, vol. 36, no. 9, 2360005, World Scientific Publishing, 2024, doi:<a href=\"https://doi.org/10.1142/s0129055x2360005x\">10.1142/s0129055x2360005x</a>.","ieee":"S. J. Henheik, A. B. Lauritsen, and B. Roos, “Universality in low-dimensional BCS theory,” <i>Reviews in Mathematical Physics</i>, vol. 36, no. 9. World Scientific Publishing, 2024.","ista":"Henheik SJ, Lauritsen AB, Roos B. 2024. Universality in low-dimensional BCS theory. Reviews in Mathematical Physics. 36(9), 2360005."},"date_published":"2024-10-01T00:00:00Z","year":"2024","doi":"10.1142/s0129055x2360005x","article_processing_charge":"Yes (in subscription journal)","publisher":"World Scientific Publishing","publication_identifier":{"issn":["0129-055X"],"eissn":["1793-6659"]},"publication_status":"published","department":[{"_id":"GradSch"},{"_id":"LaEr"},{"_id":"RoSe"}],"month":"10","date_updated":"2026-04-07T13:01:40Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_number":"2360005 ","isi":1,"title":"Universality in low-dimensional BCS theory"},{"article_number":"e78","isi":1,"title":"Pressure of a dilute spin-polarized Fermi gas: Lower bound","month":"09","department":[{"_id":"GradSch"},{"_id":"RoSe"}],"date_updated":"2026-04-07T13:01:40Z","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"doi":"10.1017/fms.2024.56","article_processing_charge":"Yes","publisher":"Cambridge University Press","publication_identifier":{"issn":["2050-5094"]},"publication_status":"published","citation":{"mla":"Lauritsen, Asbjørn Bækgaard, and Robert Seiringer. “Pressure of a Dilute Spin-Polarized Fermi Gas: Lower Bound.” <i>Forum of Mathematics, Sigma</i>, vol. 12, e78, Cambridge University Press, 2024, doi:<a href=\"https://doi.org/10.1017/fms.2024.56\">10.1017/fms.2024.56</a>.","ieee":"A. B. Lauritsen and R. Seiringer, “Pressure of a dilute spin-polarized Fermi gas: Lower bound,” <i>Forum of Mathematics, Sigma</i>, vol. 12. Cambridge University Press, 2024.","ista":"Lauritsen AB, Seiringer R. 2024. Pressure of a dilute spin-polarized Fermi gas: Lower bound. Forum of Mathematics, Sigma. 12, e78.","chicago":"Lauritsen, Asbjørn Bækgaard, and Robert Seiringer. “Pressure of a Dilute Spin-Polarized Fermi Gas: Lower Bound.” <i>Forum of Mathematics, Sigma</i>. Cambridge University Press, 2024. <a href=\"https://doi.org/10.1017/fms.2024.56\">https://doi.org/10.1017/fms.2024.56</a>.","ama":"Lauritsen AB, Seiringer R. Pressure of a dilute spin-polarized Fermi gas: Lower bound. <i>Forum of Mathematics, Sigma</i>. 2024;12. doi:<a href=\"https://doi.org/10.1017/fms.2024.56\">10.1017/fms.2024.56</a>","apa":"Lauritsen, A. B., &#38; Seiringer, R. (2024). Pressure of a dilute spin-polarized Fermi gas: Lower bound. <i>Forum of Mathematics, Sigma</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/fms.2024.56\">https://doi.org/10.1017/fms.2024.56</a>","short":"A.B. Lauritsen, R. Seiringer, Forum of Mathematics, Sigma 12 (2024)."},"date_published":"2024-09-09T00:00:00Z","year":"2024","article_type":"original","abstract":[{"lang":"eng","text":"We consider a dilute fully spin-polarized Fermi gas at positive temperature in dimensions  d∈{1,2,3} . We show that the pressure of the interacting gas is bounded from below by that of the free gas plus, to leading order, an explicit term of order  adρ2+2/d, where a is the p-wave scattering length of the repulsive interaction and  ρ  is the particle density. The results are valid for a wide range of repulsive interactions, including that of a hard core, and uniform in temperatures at most of the order of the Fermi temperature. A central ingredient in the proof is a rigorous implementation of the fermionic cluster expansion of Gaudin, Gillespie and Ripka (Nucl. Phys. A, 176.2 (1971), pp. 237–260)."}],"project":[{"name":"Mathematical Challenges in BCS Theory of Superconductivity","_id":"bda63fe5-d553-11ed-ba76-a16e3d2f256b","grant_number":"I06427"}],"external_id":{"isi":["001307817400001"],"arxiv":["2407.05990"]},"quality_controlled":"1","day":"09","oa_version":"Published Version","volume":12,"type":"journal_article","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","author":[{"last_name":"Lauritsen","full_name":"Lauritsen, Asbjørn Bækgaard","id":"e1a2682f-dc8d-11ea-abe3-81da9ac728f1","first_name":"Asbjørn Bækgaard","orcid":"0000-0003-4476-2288"},{"first_name":"Robert","orcid":"0000-0002-6781-0521","last_name":"Seiringer","full_name":"Seiringer, Robert","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87"}],"acknowledgement":"Financial support by the Austrian Science Fund (FWF) through grant DOI: 10.55776/I6427 (as part of the SFB/TRR 352) is gratefully acknowledged.","corr_author":"1","file_date_updated":"2024-09-23T09:56:17Z","arxiv":1,"_id":"18107","oa":1,"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"18135"}]},"intvolume":"        12","ddc":["510"],"file":[{"access_level":"open_access","success":1,"relation":"main_file","file_size":599886,"date_created":"2024-09-23T09:56:17Z","checksum":"330b881240013213a8e08538fec13d29","creator":"dernst","file_id":"18126","date_updated":"2024-09-23T09:56:17Z","file_name":"2024_ForumMath_Lauritsen.pdf","content_type":"application/pdf"}],"language":[{"iso":"eng"}],"publication":"Forum of Mathematics, Sigma","has_accepted_license":"1","date_created":"2024-09-20T12:25:25Z","status":"public","scopus_import":"1"},{"publication_status":"published","degree_awarded":"PhD","doi":"10.15479/at:ista:17164","publication_identifier":{"issn":["2663-337X"]},"article_processing_charge":"No","publisher":"Institute of Science and Technology Austria","citation":{"apa":"Reker, J. (2024). <i>Central limit theorems for random matrices: From resolvents to free probability</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:17164\">https://doi.org/10.15479/at:ista:17164</a>","short":"J. Reker, Central Limit Theorems for Random Matrices: From Resolvents to Free Probability, Institute of Science and Technology Austria, 2024.","chicago":"Reker, Jana. “Central Limit Theorems for Random Matrices: From Resolvents to Free Probability.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:17164\">https://doi.org/10.15479/at:ista:17164</a>.","ama":"Reker J. Central limit theorems for random matrices: From resolvents to free probability. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:17164\">10.15479/at:ista:17164</a>","ista":"Reker J. 2024. Central limit theorems for random matrices: From resolvents to free probability. Institute of Science and Technology Austria.","mla":"Reker, Jana. <i>Central Limit Theorems for Random Matrices: From Resolvents to Free Probability</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:17164\">10.15479/at:ista:17164</a>.","ieee":"J. Reker, “Central limit theorems for random matrices: From resolvents to free probability,” Institute of Science and Technology Austria, 2024."},"year":"2024","date_published":"2024-06-26T00:00:00Z","title":"Central limit theorems for random matrices: From resolvents to free probability","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"department":[{"_id":"GradSch"},{"_id":"LaEr"}],"month":"06","date_updated":"2026-04-07T13:02:13Z","project":[{"grant_number":"101020331","_id":"62796744-2b32-11ec-9570-940b20777f1d","call_identifier":"H2020","name":"Random matrices beyond Wigner-Dyson-Mehta"}],"alternative_title":["ISTA Thesis"],"oa_version":"Published Version","day":"26","ec_funded":1,"abstract":[{"lang":"eng","text":"This thesis is structured into two parts. In the first part, we consider the random\r\nvariable X := Tr(f1(W)A1 . . . fk(W)Ak) where W is an N × N Hermitian Wigner matrix, k ∈ N, and we choose (possibly N-dependent) regular functions f1, . . . , fk as well as\r\nbounded deterministic matrices A1, . . . , Ak. In this context, we prove a functional central\r\nlimit theorem on macroscopic and mesoscopic scales, showing that the fluctuations of X\r\naround its expectation are Gaussian and that the limiting covariance structure is given\r\nby a deterministic recursion. We further give explicit error bounds in terms of the scaling\r\nof f1, . . . , fk and the number of traceless matrices among A1, . . . , Ak, thus extending\r\nthe results of Cipolloni, Erdős and Schröder [40] to products of arbitrary length k ≥ 2.\r\nAnalyzing the underlying combinatorics leads to a non-recursive formula for the variance\r\nof X as well as the covariance of X and Y := Tr(fk+1(W)Ak+1 . . . fk+ℓ(W)Ak+ℓ) of similar\r\nbuild. When restricted to polynomials, these formulas reproduce recent results of Male,\r\nMingo, Peché, and Speicher [107], showing that the underlying combinatorics of noncrossing partitions and annular non-crossing permutations continue to stay valid beyond\r\nthe setting of second-order free probability theory. As an application, we consider the\r\nfluctuation of Tr(eitW A1e\r\n−itW A2)/N around its thermal value Tr(A1) Tr(A2)/N2 when t\r\nis large and give an explicit formula for the variance.\r\nThe second part of the thesis collects three smaller projects focusing on different random\r\nmatrix models. In the first project, we show that a class of weakly perturbed Hamiltonians\r\nof the form Hλ = H0 + λW, where W is a Wigner matrix, exhibits prethermalization.\r\nThat is, the time evolution generated by Hλ relaxes to its ultimate thermal state via an\r\nintermediate prethermal state with a lifetime of order λ\r\n−2\r\n. As the main result, we obtain\r\na general relaxation formula, expressing the perturbed dynamics via the unperturbed\r\ndynamics and the ultimate thermal state. The proof relies on a two-resolvent global law\r\nfor the deformed Wigner matrix Hλ.\r\nThe second project focuses on correlated random matrices, more precisely on a correlated N × N Hermitian random matrix with a polynomially decaying metric correlation\r\nstructure. A trivial a priori bound shows that the operator norm of this model is stochastically dominated by √\r\nN. However, by calculating the trace of the moments of the matrix\r\nand using the summable decay of the cumulants, the norm estimate can be improved to a\r\nbound of order one.\r\nIn the third project, we consider a multiplicative perturbation of the form UA(t) where U\r\nis a unitary random matrix and A = diag(t, 1, ..., 1). This so-called UA model was\r\nfirst introduced by Fyodorov [73] for its applications in scattering theory. We give a\r\ngeneral description of the eigenvalue trajectories obtained by varying the parameter t and\r\nintroduce a flow of deterministic domains that separates the outlier resulting from the\r\nrank-one perturbation from the typical eigenvalues for all sub-critical timescales. The\r\nresults are obtained under generic assumptions on U that hold for various unitary random\r\nmatrices, including the circular unitary ensemble (CUE) in the original formulation of\r\nthe model."}],"OA_place":"publisher","_id":"17164","related_material":{"record":[{"relation":"part_of_dissertation","id":"17173","status":"public"},{"relation":"part_of_dissertation","id":"11135","status":"public"},{"id":"17047","status":"public","relation":"part_of_dissertation"},{"id":"17154","status":"public","relation":"part_of_dissertation"},{"id":"17174","status":"public","relation":"part_of_dissertation"}]},"oa":1,"type":"dissertation","author":[{"first_name":"Jana","last_name":"Reker","id":"e796e4f9-dc8d-11ea-abe3-97e26a0323e9","full_name":"Reker, Jana"}],"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","file_date_updated":"2024-06-26T12:44:53Z","corr_author":"1","has_accepted_license":"1","language":[{"iso":"eng"}],"supervisor":[{"first_name":"László","orcid":"0000-0001-5366-9603","last_name":"Erdös","full_name":"Erdös, László","id":"4DBD5372-F248-11E8-B48F-1D18A9856A87"}],"status":"public","date_created":"2024-06-24T11:23:29Z","keyword":["Random Matrices","Spectrum","Central Limit Theorem","Resolvent","Free Probability"],"page":"206","file":[{"file_size":2783027,"relation":"main_file","access_level":"open_access","checksum":"fb16d86e1f2753dc3a9e14d2bdfd84cd","date_created":"2024-06-26T12:39:36Z","creator":"jreker","file_id":"17176","content_type":"application/pdf","file_name":"ISTA_Thesis_JReker.pdf","date_updated":"2024-06-26T12:44:53Z"},{"content_type":"application/zip","date_updated":"2024-06-26T12:44:53Z","file_name":"ISTA_Thesis_JReker_SourceFiles.zip","creator":"jreker","file_id":"17177","checksum":"cb1e54009d47c1dcf5b866c4566fa27f","date_created":"2024-06-26T12:39:42Z","relation":"source_file","file_size":3054878,"access_level":"closed"}],"ddc":["519"]}]