--- OA_place: repository _id: '17350' abstract: - lang: eng text: "Score-based generative models (SGMs) are powerful tools to sample from\r\ncomplex data distributions. Their underlying idea is to (i) run a forward\r\nprocess for time $T_1$ by adding noise to the data, (ii) estimate its score\r\nfunction, and (iii) use such estimate to run a reverse process. As the reverse\r\nprocess is initialized with the stationary distribution of the forward one, the\r\nexisting analysis paradigm requires $T_1\\to\\infty$. This is however\r\nproblematic: from a theoretical viewpoint, for a given precision of the score\r\napproximation, the convergence guarantee fails as $T_1$ diverges; from a\r\npractical viewpoint, a large $T_1$ increases computational costs and leads to\r\nerror propagation. This paper addresses the issue by considering a version of\r\nthe popular predictor-corrector scheme: after running the forward process, we\r\nfirst estimate the final distribution via an inexact Langevin dynamics and then\r\nrevert the process. Our key technical contribution is to provide convergence\r\nguarantees which require to run the forward process only for a fixed finite\r\ntime $T_1$. Our bounds exhibit a mild logarithmic dependence on the input\r\ndimension and the subgaussian norm of the target distribution, have minimal\r\nassumptions on the data, and require only to control the $L^2$ loss on the\r\nscore approximation, which is the quantity minimized in practice." article_processing_charge: No arxiv: 1 author: - first_name: Francesco full_name: Pedrotti, Francesco id: d3ac8ac6-dc8d-11ea-abe3-e2a9628c4c3c last_name: Pedrotti - first_name: Jan full_name: Maas, Jan id: 4C5696CE-F248-11E8-B48F-1D18A9856A87 last_name: Maas orcid: 0000-0002-0845-1338 - first_name: Marco full_name: Mondelli, Marco id: 27EB676C-8706-11E9-9510-7717E6697425 last_name: Mondelli orcid: 0000-0002-3242-7020 citation: ama: Pedrotti F, Maas J, Mondelli M. Improved convergence of score-based diffusion models via prediction-correction. arXiv. doi:10.48550/arXiv.2305.14164 apa: Pedrotti, F., Maas, J., & Mondelli, M. (n.d.). Improved convergence of score-based diffusion models via prediction-correction. arXiv. https://doi.org/10.48550/arXiv.2305.14164 chicago: Pedrotti, Francesco, Jan Maas, and Marco Mondelli. “Improved Convergence of Score-Based Diffusion Models via Prediction-Correction.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2305.14164. ieee: F. Pedrotti, J. Maas, and M. Mondelli, “Improved convergence of score-based diffusion models via prediction-correction,” arXiv. . ista: Pedrotti F, Maas J, Mondelli M. Improved convergence of score-based diffusion models via prediction-correction. arXiv, 10.48550/arXiv.2305.14164. mla: Pedrotti, Francesco, et al. “Improved Convergence of Score-Based Diffusion Models via Prediction-Correction.” ArXiv, doi:10.48550/arXiv.2305.14164. short: F. Pedrotti, J. Maas, M. Mondelli, ArXiv (n.d.). corr_author: '1' date_created: 2024-07-31T07:56:40Z date_published: 2024-06-06T00:00:00Z date_updated: 2026-04-07T13:00:02Z day: '06' department: - _id: JaMa - _id: MaMo doi: 10.48550/arXiv.2305.14164 external_id: arxiv: - '2305.14164' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2305.14164 month: '06' oa: 1 oa_version: Preprint project: - _id: fc31cba2-9c52-11eb-aca3-ff467d239cd2 grant_number: F6504 name: Taming Complexity in Partial Differential Systems - _id: 059876FA-7A3F-11EA-A408-12923DDC885E name: Prix Lopez-Loretta 2019 - Marco Mondelli publication: arXiv publication_status: draft related_material: record: - id: '18897' relation: later_version status: public - id: '17336' relation: dissertation_contains status: public status: public title: Improved convergence of score-based diffusion models via prediction-correction type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository _id: '17352' abstract: - lang: eng text: "We prove upper bounds on the $L^\\infty$-Wasserstein distance from optimal\r\ntransport between strongly log-concave probability densities and log-Lipschitz\r\nperturbations. In the simplest setting, such a bound amounts to a\r\ntransport-information inequality involving the $L^\\infty$-Wasserstein metric\r\nand the relative $L^\\infty$-Fisher information. We show that this inequality\r\ncan be sharpened significantly in situations where the involved densities are\r\nanisotropic. Our proof is based on probabilistic techniques using Langevin\r\ndynamics. As an application of these results, we obtain sharp exponential rates\r\nof convergence in Fisher's infinitesimal model from quantitative genetics,\r\ngeneralising recent results by Calvez, Poyato, and Santambrogio in dimension 1\r\nto arbitrary dimensions." article_number: '2402.04151' article_processing_charge: No arxiv: 1 author: - first_name: Kseniia full_name: Khudiakova, Kseniia id: 4E6DC800-AE37-11E9-AC72-31CAE5697425 last_name: Khudiakova orcid: 0000-0002-6246-1465 - first_name: Jan full_name: Maas, Jan id: 4C5696CE-F248-11E8-B48F-1D18A9856A87 last_name: Maas orcid: 0000-0002-0845-1338 - first_name: Francesco full_name: Pedrotti, Francesco id: d3ac8ac6-dc8d-11ea-abe3-e2a9628c4c3c last_name: Pedrotti citation: ama: Khudiakova K, Maas J, Pedrotti F. L∞-optimal transport of anisotropic log-concave measures and exponential convergence in Fisher’s infinitesimal model. arXiv. doi:10.48550/arXiv.2402.04151 apa: Khudiakova, K., Maas, J., & Pedrotti, F. (n.d.). L∞-optimal transport of anisotropic log-concave measures and exponential convergence in Fisher’s infinitesimal model. arXiv. https://doi.org/10.48550/arXiv.2402.04151 chicago: Khudiakova, Kseniia, Jan Maas, and Francesco Pedrotti. “L∞-Optimal Transport of Anisotropic Log-Concave Measures and Exponential Convergence in Fisher’s Infinitesimal Model.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2402.04151. ieee: K. Khudiakova, J. Maas, and F. Pedrotti, “L∞-optimal transport of anisotropic log-concave measures and exponential convergence in Fisher’s infinitesimal model,” arXiv. . ista: Khudiakova K, Maas J, Pedrotti F. L∞-optimal transport of anisotropic log-concave measures and exponential convergence in Fisher’s infinitesimal model. arXiv, 2402.04151. mla: Khudiakova, Kseniia, et al. “L∞-Optimal Transport of Anisotropic Log-Concave Measures and Exponential Convergence in Fisher’s Infinitesimal Model.” ArXiv, 2402.04151, doi:10.48550/arXiv.2402.04151. short: K. Khudiakova, J. Maas, F. Pedrotti, ArXiv (n.d.). corr_author: '1' date_created: 2024-07-31T08:07:40Z date_published: 2024-02-07T00:00:00Z date_updated: 2026-04-07T13:00:02Z day: '07' department: - _id: JaMa doi: 10.48550/arXiv.2402.04151 external_id: arxiv: - '2402.04151' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2402.04151 month: '02' oa: 1 oa_version: Preprint project: - _id: fc31cba2-9c52-11eb-aca3-ff467d239cd2 grant_number: F6504 name: Taming Complexity in Partial Differential Systems - _id: 34d33d68-11ca-11ed-8bc3-ec13763c0ca8 grant_number: '26293' name: The impact of deleterious mutations on small populations publication: arXiv publication_status: draft related_material: record: - id: '20050' relation: later_version status: public - id: '17336' relation: dissertation_contains status: public status: public title: L∞-optimal transport of anisotropic log-concave measures and exponential convergence in Fisher's infinitesimal model type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository _id: '17353' abstract: - lang: eng text: "In this paper we derive estimates for the Hessian of the logarithm\r\n(log-Hessian) for solutions to the heat equation. For initial data in the form\r\nof log-Lipschitz perturbation of strongly log-concave measures, the log-Hessian\r\nadmits an explicit, uniform (in space) lower bound. This yields a new estimate\r\nfor the Lipschitz constant of a transport map pushing forward the standard\r\nGaussian to a measure in this class. Further connections are discussed with\r\nscore-based diffusion models and improved Gaussian logarithmic Sobolev\r\ninequalities. Finally, we show that assuming only fast decay of the tails of\r\nthe initial datum does not suffice to guarantee uniform log-Hessian upper\r\nbounds." article_number: '2404.15205' article_processing_charge: No arxiv: 1 author: - first_name: Giovanni full_name: Brigati, Giovanni id: 63ff57e8-1fbb-11ee-88f2-f558ffc59cf1 last_name: Brigati - first_name: Francesco full_name: Pedrotti, Francesco id: d3ac8ac6-dc8d-11ea-abe3-e2a9628c4c3c last_name: Pedrotti citation: ama: Brigati G, Pedrotti F. Heat flow, log-concavity, and Lipschitz transport maps. arXiv. doi:10.48550/arXiv.2404.15205 apa: Brigati, G., & Pedrotti, F. (n.d.). Heat flow, log-concavity, and Lipschitz transport maps. arXiv. https://doi.org/10.48550/arXiv.2404.15205 chicago: Brigati, Giovanni, and Francesco Pedrotti. “Heat Flow, Log-Concavity, and Lipschitz Transport Maps.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2404.15205. ieee: G. Brigati and F. Pedrotti, “Heat flow, log-concavity, and Lipschitz transport maps,” arXiv. . ista: Brigati G, Pedrotti F. Heat flow, log-concavity, and Lipschitz transport maps. arXiv, 2404.15205. mla: Brigati, Giovanni, and Francesco Pedrotti. “Heat Flow, Log-Concavity, and Lipschitz Transport Maps.” ArXiv, 2404.15205, doi:10.48550/arXiv.2404.15205. short: G. Brigati, F. Pedrotti, ArXiv (n.d.). corr_author: '1' date_created: 2024-07-31T08:17:14Z date_published: 2024-05-08T00:00:00Z date_updated: 2026-04-07T13:00:02Z day: '08' department: - _id: JaMa doi: 10.48550/arXiv.2404.15205 external_id: arxiv: - '2404.15205' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2404.15205 month: '05' oa: 1 oa_version: Preprint publication: arXiv publication_status: draft related_material: record: - id: '20591' relation: later_version status: public - id: '17336' relation: dissertation_contains status: public status: public title: Heat flow, log-concavity, and Lipschitz transport maps type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: publisher _id: '18088' abstract: - lang: eng 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. " alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Guillermo full_name: Pascual Perez, Guillermo id: 2D7ABD02-F248-11E8-B48F-1D18A9856A87 last_name: Pascual Perez orcid: 0000-0001-8630-415X citation: ama: Pascual Perez G. On the efficiency and security of secure group messaging. 2024. doi:10.15479/at:ista:18088 apa: Pascual Perez, G. (2024). On the efficiency and security of secure group messaging. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:18088 chicago: Pascual Perez, Guillermo. “On the Efficiency and Security of Secure Group Messaging.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:18088. 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. mla: Pascual Perez, Guillermo. On the Efficiency and Security of Secure Group Messaging. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:18088. short: G. Pascual Perez, On the Efficiency and Security of Secure Group Messaging, Institute of Science and Technology Austria, 2024. corr_author: '1' date_created: 2024-09-18T12:59:49Z date_published: 2024-09-18T00:00:00Z date_updated: 2026-04-07T13:01:26Z day: '18' ddc: - '000' degree_awarded: PhD department: - _id: KrPi - _id: GradSch doi: 10.15479/at:ista:18088 ec_funded: 1 file: - access_level: closed checksum: ce0dca715b3df48e52e2e891b6ac1bc5 content_type: application/x-zip-compressed creator: gpascual date_created: 2024-09-19T12:35:38Z date_updated: 2024-09-19T12:35:38Z file_id: '18099' file_name: thesis_bundle.zip file_size: 11917734 relation: source_file - access_level: open_access checksum: 4a2c72e90f1a0ef2a13cff800f8d1265 content_type: application/pdf creator: gpascual date_created: 2024-09-19T12:36:08Z date_updated: 2024-09-19T12:36:08Z file_id: '18100' file_name: thesis_gpasper.pdf file_size: 2729427 relation: main_file file_date_updated: 2024-09-19T12:36:08Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '239' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '10408' relation: part_of_dissertation status: public - id: '11476' relation: part_of_dissertation status: public - id: '18086' relation: part_of_dissertation status: public - id: '10049' relation: part_of_dissertation status: public status: public supervisor: - first_name: Krzysztof Z full_name: Pietrzak, Krzysztof Z id: 3E04A7AA-F248-11E8-B48F-1D18A9856A87 last_name: Pietrzak orcid: 0000-0002-9139-1654 title: On the efficiency and security of secure group messaging tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- OA_place: publisher _id: '17490' 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" acknowledged_ssus: - _id: ScienComp alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Ilia full_name: Markov, Ilia id: D0CF4148-C985-11E9-8066-0BDEE5697425 last_name: Markov citation: ama: 'Markov I. Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective. 2024. doi:10.15479/at:ista:17490' apa: 'Markov, I. (2024). Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:17490' chicago: 'Markov, Ilia. “Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:17490.' ieee: 'I. Markov, “Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective,” Institute of Science and Technology Austria, 2024.' 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. Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:17490.' short: 'I. Markov, Communication-Efficient Distributed Training of Deep Neural Networks : An Algorithms and Systems Perspective, Institute of Science and Technology Austria, 2024.' corr_author: '1' date_created: 2024-09-04T08:51:11Z date_published: 2024-09-04T00:00:00Z date_updated: 2026-04-07T13:00:54Z day: '04' ddc: - '000' degree_awarded: PhD department: - _id: GradSch - _id: DaAl doi: 10.15479/at:ista:17490 ec_funded: 1 file: - access_level: closed checksum: 77609f4835d2730e46fa0d42d9134ed9 content_type: application/x-zip-compressed creator: imarkov date_created: 2024-09-04T08:35:35Z date_updated: 2024-09-04T08:35:35Z file_id: '17491' file_name: Thesis.zip file_size: 43327753 relation: source_file - access_level: open_access checksum: 9e68f7217570f756ceb8f70b980938cd content_type: application/pdf creator: imarkov date_created: 2024-09-04T08:36:06Z date_updated: 2024-09-04T08:36:06Z file_id: '17492' file_name: Thesis_final_version_pdfa2.pdf file_size: 2756082 relation: main_file success: 1 file_date_updated: 2024-09-04T08:36:06Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '102' project: - _id: 268A44D6-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '805223' name: Elastic Coordination for Scalable Machine Learning publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '17456' relation: part_of_dissertation status: public - id: '14461' relation: part_of_dissertation status: public - id: '12780' relation: part_of_dissertation status: public status: public supervisor: - first_name: Dan-Adrian full_name: Alistarh, Dan-Adrian id: 4A899BFC-F248-11E8-B48F-1D18A9856A87 last_name: Alistarh orcid: 0000-0003-3650-940X title: 'Communication-efficient distributed training of deep neural networks : An algorithms and systems perspective' tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- _id: '18086' 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." alternative_title: - LNCS article_processing_charge: No author: - first_name: Joel F full_name: Alwen, Joel F id: 2A8DFA8C-F248-11E8-B48F-1D18A9856A87 last_name: Alwen - first_name: Benedikt full_name: Auerbach, Benedikt id: D33D2B18-E445-11E9-ABB7-15F4E5697425 last_name: Auerbach orcid: 0000-0002-7553-6606 - first_name: Miguel full_name: Cueto Noval, Miguel id: ffc563a3-f6e0-11ea-865d-e3cce03d17cc last_name: Cueto Noval orcid: 0000-0002-2505-4246 - first_name: Karen full_name: Klein, Karen id: 3E83A2F8-F248-11E8-B48F-1D18A9856A87 last_name: Klein - first_name: Guillermo full_name: Pascual Perez, Guillermo id: 2D7ABD02-F248-11E8-B48F-1D18A9856A87 last_name: Pascual Perez orcid: 0000-0001-8630-415X - first_name: Krzysztof Z full_name: Pietrzak, Krzysztof Z id: 3E04A7AA-F248-11E8-B48F-1D18A9856A87 last_name: Pietrzak orcid: 0000-0002-9139-1654 citation: 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. Security and Cryptography for Networks: 14th International Conference. Vol 14974. Cham: Springer Nature; 2024:294–313. doi:10.1007/978-3-031-71073-5_14' apa: 'Alwen, J. F., Auerbach, B., Cueto Noval, M., Klein, K., Pascual Perez, G., & Pietrzak, K. Z. (2024). DeCAF: Decentralizable CGKA with fast healing. In C. Galdi & D. H. Phan (Eds.), Security and Cryptography for Networks: 14th International Conference (Vol. 14974, pp. 294–313). Cham: Springer Nature. https://doi.org/10.1007/978-3-031-71073-5_14' 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 Security and Cryptography for Networks: 14th International Conference, edited by Clemente Galdi and Duong Hieu Phan, 14974:294–313. Cham: Springer Nature, 2024. https://doi.org/10.1007/978-3-031-71073-5_14.' 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 Security and Cryptography for Networks: 14th International Conference, Amalfi, Italy, 2024, vol. 14974, pp. 294–313.' 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.' mla: 'Alwen, Joel F., et al. “DeCAF: Decentralizable CGKA with Fast Healing.” Security and Cryptography for Networks: 14th International Conference, edited by Clemente Galdi and Duong Hieu Phan, vol. 14974, Springer Nature, 2024, pp. 294–313, doi:10.1007/978-3-031-71073-5_14.' 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.' conference: end_date: 2024-09-13 location: Amalfi, Italy name: 'SCN: Security and Cryptography for Networks' start_date: 2024-09-11 corr_author: '1' date_created: 2024-09-18T11:35:14Z date_published: 2024-09-10T00:00:00Z date_updated: 2026-04-07T13:01:26Z day: '10' department: - _id: GradSch - _id: KrPi doi: 10.1007/978-3-031-71073-5_14 editor: - first_name: Clemente full_name: Galdi, Clemente last_name: Galdi - first_name: Duong Hieu full_name: Phan, Duong Hieu last_name: Phan external_id: isi: - '001330408000014' intvolume: ' 14974' isi: 1 language: - iso: eng month: '09' oa_version: None page: 294–313 place: Cham publication: 'Security and Cryptography for Networks: 14th International Conference' publication_identifier: eisbn: - '9783031710735' eissn: - 1611-3349 isbn: - '9783031710728' issn: - 0302-9743 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: record: - id: '18088' relation: dissertation_contains status: public status: public title: 'DeCAF: Decentralizable CGKA with fast healing' type: conference user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 14974 year: '2024' ... --- _id: '17456' abstract: - lang: eng text: "Data-parallel distributed training of deep neural networks (DNN) has gained very widespread adoption, but can still experience communication bottlenecks. To address this issue, entire families of compression mechanisms have been developed, including quantization, sparsification, and low-rank approximation, some of which are seeing significant practical adoption. Despite this progress, almost all known compression schemes apply compression uniformly across DNN layers, although layers are heterogeneous in terms of parameter count and their impact on model accuracy.In this work, we provide a general framework for adapting the degree of compression across the model's layers dynamically during training, improving the overall compression, while leading to substantial speedups, without sacrificing accuracy. Our framework, called L-GreCo, is based on an adaptive algorithm, which automatically picks the optimal compression parameters for model layers guaranteeing the best compression ratio while satisfying an error constraint. Extensive experiments over image classification and language modeling tasks shows that L-GreCo is effective across all existing families of compression methods, and achieves up to 2.5\r\n×\r\n training speedup and up to 5\r\n×\r\n compression improvement over efficient implementations of existing approaches, while recovering full accuracy. Moreover, L-GreCo is complementary to existing adaptive algorithms, improving their compression ratio by 50\\% and practical throughput by 66\\%. An anonymized implementation is available at https://github.com/LGrCo/L-GreCo." article_processing_charge: No arxiv: 1 author: - first_name: Ilia full_name: Markov, Ilia id: D0CF4148-C985-11E9-8066-0BDEE5697425 last_name: Markov - first_name: Kaveh full_name: Alimohammadi, Kaveh last_name: Alimohammadi - first_name: Elias full_name: Frantar, Elias id: 09a8f98d-ec99-11ea-ae11-c063a7b7fe5f last_name: Frantar - first_name: Dan-Adrian full_name: Alistarh, Dan-Adrian id: 4A899BFC-F248-11E8-B48F-1D18A9856A87 last_name: Alistarh orcid: 0000-0003-3650-940X citation: ama: 'Markov I, Alimohammadi K, Frantar E, Alistarh D-A. L-GreCo: Layerwise-adaptive gradient compression for efficient data-parallel deep learning. In: Gibbons P, Pekhimenko G, De Sa C, eds. Proceedings of Machine Learning and Systems . Vol 6. Association for Computing Machinery; 2024.' apa: 'Markov, I., Alimohammadi, K., Frantar, E., & Alistarh, D.-A. (2024). L-GreCo: Layerwise-adaptive gradient compression for efficient data-parallel deep learning. In P. Gibbons, G. Pekhimenko, & C. De Sa (Eds.), Proceedings of Machine Learning and Systems (Vol. 6). Athens, Greece: Association for Computing Machinery.' chicago: 'Markov, Ilia, Kaveh Alimohammadi, Elias Frantar, and Dan-Adrian Alistarh. “L-GreCo: Layerwise-Adaptive Gradient Compression for Efficient Data-Parallel Deep Learning.” In Proceedings of Machine Learning and Systems , edited by P. Gibbons, G. Pekhimenko, and C. De Sa, Vol. 6. Association for Computing Machinery, 2024.' ieee: 'I. Markov, K. Alimohammadi, E. Frantar, and D.-A. Alistarh, “L-GreCo: Layerwise-adaptive gradient compression for efficient data-parallel deep learning,” in Proceedings of Machine Learning and Systems , Athens, Greece, 2024, vol. 6.' ista: 'Markov I, Alimohammadi K, Frantar E, Alistarh D-A. 2024. L-GreCo: Layerwise-adaptive gradient compression for efficient data-parallel deep learning. Proceedings of Machine Learning and Systems . MLSys: Machine Learning and Systems vol. 6.' mla: 'Markov, Ilia, et al. “L-GreCo: Layerwise-Adaptive Gradient Compression for Efficient Data-Parallel Deep Learning.” Proceedings of Machine Learning and Systems , edited by P. Gibbons et al., vol. 6, Association for Computing Machinery, 2024.' short: I. Markov, K. Alimohammadi, E. Frantar, D.-A. Alistarh, in:, P. Gibbons, G. Pekhimenko, C. De Sa (Eds.), Proceedings of Machine Learning and Systems , Association for Computing Machinery, 2024. conference: end_date: 2024-04-22 location: Athens, Greece name: 'MLSys: Machine Learning and Systems' start_date: 2024-04-22 corr_author: '1' date_created: 2024-08-22T08:29:25Z date_published: 2024-04-01T00:00:00Z date_updated: 2026-04-07T13:00:54Z day: '01' department: - _id: DaAl editor: - first_name: P. full_name: Gibbons, P. last_name: Gibbons - first_name: G. full_name: Pekhimenko, G. last_name: Pekhimenko - first_name: C. full_name: De Sa, C. last_name: De Sa external_id: arxiv: - '2210.17357' intvolume: ' 6' language: - iso: eng main_file_link: - open_access: '1' url: https://proceedings.mlsys.org/paper_files/paper/2024/hash/9069a8976ff06f6443e7f4172990a580-Abstract-Conference.html month: '04' oa: 1 oa_version: Published Version publication: 'Proceedings of Machine Learning and Systems ' publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' related_material: record: - id: '17490' relation: dissertation_contains status: public status: public title: 'L-GreCo: Layerwise-adaptive gradient compression for efficient data-parallel deep learning' type: conference user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 volume: 6 year: '2024' ... --- OA_place: publisher OA_type: hybrid _id: '14542' 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." 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. article_number: '2360005 ' article_processing_charge: Yes (in subscription journal) article_type: original arxiv: 1 author: - first_name: Sven Joscha full_name: Henheik, Sven Joscha id: 31d731d7-d235-11ea-ad11-b50331c8d7fb last_name: Henheik orcid: 0000-0003-1106-327X - first_name: Asbjørn Bækgaard full_name: Lauritsen, Asbjørn Bækgaard id: e1a2682f-dc8d-11ea-abe3-81da9ac728f1 last_name: Lauritsen orcid: 0000-0003-4476-2288 - first_name: Barbara full_name: Roos, Barbara id: 5DA90512-D80F-11E9-8994-2E2EE6697425 last_name: Roos orcid: 0000-0002-9071-5880 citation: ama: Henheik SJ, Lauritsen AB, Roos B. Universality in low-dimensional BCS theory. Reviews in Mathematical Physics. 2024;36(9). doi:10.1142/s0129055x2360005x apa: Henheik, S. J., Lauritsen, A. B., & Roos, B. (2024). Universality in low-dimensional BCS theory. Reviews in Mathematical Physics. World Scientific Publishing. https://doi.org/10.1142/s0129055x2360005x chicago: Henheik, Sven Joscha, Asbjørn Bækgaard Lauritsen, and Barbara Roos. “Universality in Low-Dimensional BCS Theory.” Reviews in Mathematical Physics. World Scientific Publishing, 2024. https://doi.org/10.1142/s0129055x2360005x. ieee: S. J. Henheik, A. B. Lauritsen, and B. Roos, “Universality in low-dimensional BCS theory,” Reviews in Mathematical Physics, 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. mla: Henheik, Sven Joscha, et al. “Universality in Low-Dimensional BCS Theory.” Reviews in Mathematical Physics, vol. 36, no. 9, 2360005, World Scientific Publishing, 2024, doi:10.1142/s0129055x2360005x. short: S.J. Henheik, A.B. Lauritsen, B. Roos, Reviews in Mathematical Physics 36 (2024). corr_author: '1' date_created: 2023-11-15T23:48:14Z date_published: 2024-10-01T00:00:00Z date_updated: 2026-04-07T13:01:40Z day: '01' ddc: - '510' department: - _id: GradSch - _id: LaEr - _id: RoSe doi: 10.1142/s0129055x2360005x ec_funded: 1 external_id: arxiv: - '2301.05621' isi: - '001099640300002' file: - access_level: open_access checksum: 2b053a4223b4db14b90520999ec56054 content_type: application/pdf creator: dernst date_created: 2025-01-09T07:56:28Z date_updated: 2025-01-09T07:56:28Z file_id: '18786' file_name: 2024_ReviewsmathPhysics_Henheik.pdf file_size: 503910 relation: main_file success: 1 file_date_updated: 2025-01-09T07:56:28Z has_accepted_license: '1' intvolume: ' 36' isi: 1 issue: '9' language: - iso: eng month: '10' oa: 1 oa_version: Published Version project: - _id: 62796744-2b32-11ec-9570-940b20777f1d call_identifier: H2020 grant_number: '101020331' name: Random matrices beyond Wigner-Dyson-Mehta - _id: bda63fe5-d553-11ed-ba76-a16e3d2f256b grant_number: I06427 name: Mathematical Challenges in BCS Theory of Superconductivity publication: Reviews in Mathematical Physics publication_identifier: eissn: - 1793-6659 issn: - 0129-055X publication_status: published publisher: World Scientific Publishing quality_controlled: '1' related_material: record: - id: '19540' relation: dissertation_contains status: public - id: '18135' relation: dissertation_contains status: public scopus_import: '1' status: public title: Universality in low-dimensional BCS theory tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 36 year: '2024' ... --- _id: '18107' 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). 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.' article_number: e78 article_processing_charge: Yes article_type: original arxiv: 1 author: - first_name: Asbjørn Bækgaard full_name: Lauritsen, Asbjørn Bækgaard id: e1a2682f-dc8d-11ea-abe3-81da9ac728f1 last_name: Lauritsen orcid: 0000-0003-4476-2288 - first_name: Robert full_name: Seiringer, Robert id: 4AFD0470-F248-11E8-B48F-1D18A9856A87 last_name: Seiringer orcid: 0000-0002-6781-0521 citation: ama: 'Lauritsen AB, Seiringer R. Pressure of a dilute spin-polarized Fermi gas: Lower bound. Forum of Mathematics, Sigma. 2024;12. doi:10.1017/fms.2024.56' apa: 'Lauritsen, A. B., & Seiringer, R. (2024). Pressure of a dilute spin-polarized Fermi gas: Lower bound. Forum of Mathematics, Sigma. Cambridge University Press. https://doi.org/10.1017/fms.2024.56' chicago: 'Lauritsen, Asbjørn Bækgaard, and Robert Seiringer. “Pressure of a Dilute Spin-Polarized Fermi Gas: Lower Bound.” Forum of Mathematics, Sigma. Cambridge University Press, 2024. https://doi.org/10.1017/fms.2024.56.' ieee: 'A. B. Lauritsen and R. Seiringer, “Pressure of a dilute spin-polarized Fermi gas: Lower bound,” Forum of Mathematics, Sigma, 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.' mla: 'Lauritsen, Asbjørn Bækgaard, and Robert Seiringer. “Pressure of a Dilute Spin-Polarized Fermi Gas: Lower Bound.” Forum of Mathematics, Sigma, vol. 12, e78, Cambridge University Press, 2024, doi:10.1017/fms.2024.56.' short: A.B. Lauritsen, R. Seiringer, Forum of Mathematics, Sigma 12 (2024). corr_author: '1' date_created: 2024-09-20T12:25:25Z date_published: 2024-09-09T00:00:00Z date_updated: 2026-04-07T13:01:40Z day: '09' ddc: - '510' department: - _id: GradSch - _id: RoSe doi: 10.1017/fms.2024.56 external_id: arxiv: - '2407.05990' isi: - '001307817400001' file: - access_level: open_access checksum: 330b881240013213a8e08538fec13d29 content_type: application/pdf creator: dernst date_created: 2024-09-23T09:56:17Z date_updated: 2024-09-23T09:56:17Z file_id: '18126' file_name: 2024_ForumMath_Lauritsen.pdf file_size: 599886 relation: main_file success: 1 file_date_updated: 2024-09-23T09:56:17Z has_accepted_license: '1' intvolume: ' 12' isi: 1 language: - iso: eng month: '09' oa: 1 oa_version: Published Version project: - _id: bda63fe5-d553-11ed-ba76-a16e3d2f256b grant_number: I06427 name: Mathematical Challenges in BCS Theory of Superconductivity publication: Forum of Mathematics, Sigma publication_identifier: issn: - 2050-5094 publication_status: published publisher: Cambridge University Press quality_controlled: '1' related_material: record: - id: '18135' relation: dissertation_contains status: public scopus_import: '1' status: public title: 'Pressure of a dilute spin-polarized Fermi gas: Lower bound' tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 12 year: '2024' ... --- OA_place: publisher _id: '17164' 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." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Jana full_name: Reker, Jana id: e796e4f9-dc8d-11ea-abe3-97e26a0323e9 last_name: Reker citation: ama: 'Reker J. Central limit theorems for random matrices: From resolvents to free probability. 2024. doi:10.15479/at:ista:17164' apa: 'Reker, J. (2024). Central limit theorems for random matrices: From resolvents to free probability. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:17164' chicago: 'Reker, Jana. “Central Limit Theorems for Random Matrices: From Resolvents to Free Probability.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:17164.' ieee: 'J. Reker, “Central limit theorems for random matrices: From resolvents to free probability,” Institute of Science and Technology Austria, 2024.' ista: 'Reker J. 2024. Central limit theorems for random matrices: From resolvents to free probability. Institute of Science and Technology Austria.' mla: 'Reker, Jana. Central Limit Theorems for Random Matrices: From Resolvents to Free Probability. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:17164.' short: 'J. Reker, Central Limit Theorems for Random Matrices: From Resolvents to Free Probability, Institute of Science and Technology Austria, 2024.' corr_author: '1' date_created: 2024-06-24T11:23:29Z date_published: 2024-06-26T00:00:00Z date_updated: 2026-04-07T13:02:13Z day: '26' ddc: - '519' degree_awarded: PhD department: - _id: GradSch - _id: LaEr doi: 10.15479/at:ista:17164 ec_funded: 1 file: - access_level: open_access checksum: fb16d86e1f2753dc3a9e14d2bdfd84cd content_type: application/pdf creator: jreker date_created: 2024-06-26T12:39:36Z date_updated: 2024-06-26T12:44:53Z file_id: '17176' file_name: ISTA_Thesis_JReker.pdf file_size: 2783027 relation: main_file - access_level: closed checksum: cb1e54009d47c1dcf5b866c4566fa27f content_type: application/zip creator: jreker date_created: 2024-06-26T12:39:42Z date_updated: 2024-06-26T12:44:53Z file_id: '17177' file_name: ISTA_Thesis_JReker_SourceFiles.zip file_size: 3054878 relation: source_file file_date_updated: 2024-06-26T12:44:53Z has_accepted_license: '1' keyword: - Random Matrices - Spectrum - Central Limit Theorem - Resolvent - Free Probability language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: '206' project: - _id: 62796744-2b32-11ec-9570-940b20777f1d call_identifier: H2020 grant_number: '101020331' name: Random matrices beyond Wigner-Dyson-Mehta publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '17173' relation: part_of_dissertation status: public - id: '11135' relation: part_of_dissertation status: public - id: '17047' relation: part_of_dissertation status: public - id: '17154' relation: part_of_dissertation status: public - id: '17174' relation: part_of_dissertation status: public status: public supervisor: - first_name: László full_name: Erdös, László id: 4DBD5372-F248-11E8-B48F-1D18A9856A87 last_name: Erdös orcid: 0000-0001-5366-9603 title: 'Central limit theorems for random matrices: From resolvents to free probability' tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- OA_place: publisher OA_type: hybrid _id: '17219' abstract: - lang: eng text: 'We introduce a multi-material non-manifold mesh-based surface tracking algorithm that converts self-intersections into topological changes. Our algorithm generalizes prior work on manifold surface tracking with topological changes: it preserves surface features like mesh-based methods, and it robustly handles topological changes like level set methods. Our method also offers improved efficiency and robustness over the state of the art. We demonstrate the effectiveness of the approach on a range of examples, including complex soap film simulations with thousands of interacting bubbles, and boolean unions of non-manifold meshes consisting of millions of triangles.' acknowledgement: Peter Heiss-Synak helped conceive the project, helped formulate the algorithm structure, contributed ideas and code to Sections 6 & 8, the mesh data structure, algorithm robustness and benchmarks, helped write the paper, and provided supervision and conceptual solutions throughout the project. Aleksei Kalinov contributed ideas and code to Sections 7, 8.5, and 5, the sparse grid data structure, algorithm robustness and benchmarks, optimized the performance, produced all results, most figures, and the supplementary video, helped write the text, and provided conceptual solutions throughout the project. Malina Strugaru helped implement the mesh data structure and designed re-meshing operations for non-manifold triangle meshes. Arian Etemadi developed early prototypes for ideas in Sections 8.1 and 8.3 and helped write the paper. Huidong Yang developed early prototypes for isosurface extraction and visualization. Chris Wojtan helped conceive the project, helped write the paper, and provided supervision, prototype grid data structure code, and conceptual solutions throughout the project. We thank the anonymous reviewers for their helpful comments, the members of the Visual Computing Group at ISTA for their feedback, Christopher Batty for discussions about LosTopos, and SideFX for the Houdini Education software licenses. This research was funded in part by the European Union (ERC-2021-COG 101045083 CoDiNA). article_number: '54' article_processing_charge: Yes (via OA deal) article_type: original author: - first_name: Peter full_name: Synak, Peter id: 331776E2-F248-11E8-B48F-1D18A9856A87 last_name: Synak - first_name: Aleksei full_name: Kalinov, Aleksei id: 44b7120e-eb97-11eb-a6c2-e1557aa81d02 last_name: Kalinov orcid: 0000-0003-2189-3904 - first_name: Irina-Malina full_name: Strugaru, Irina-Malina id: 2afc607f-f128-11eb-9611-8f2a0dfcf074 last_name: Strugaru - first_name: Arian full_name: Etemadihaghighi, Arian id: 36cea3aa-f38e-11ec-8ae0-c65ae6f6098f last_name: Etemadihaghighi - first_name: Huidong full_name: Yang, Huidong last_name: Yang - first_name: Christopher J full_name: Wojtan, Christopher J id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87 last_name: Wojtan orcid: 0000-0001-6646-5546 citation: ama: Synak P, Kalinov A, Strugaru I-M, Etemadi A, Yang H, Wojtan C. Multi-material mesh-based surface tracking with implicit topology changes. ACM Transactions on Graphics. 2024;43(4). doi:10.1145/3658223 apa: Synak, P., Kalinov, A., Strugaru, I.-M., Etemadi, A., Yang, H., & Wojtan, C. (2024). Multi-material mesh-based surface tracking with implicit topology changes. ACM Transactions on Graphics. Association for Computing Machinery. https://doi.org/10.1145/3658223 chicago: Synak, Peter, Aleksei Kalinov, Irina-Malina Strugaru, Arian Etemadi, Huidong Yang, and Chris Wojtan. “Multi-Material Mesh-Based Surface Tracking with Implicit Topology Changes.” ACM Transactions on Graphics. Association for Computing Machinery, 2024. https://doi.org/10.1145/3658223. ieee: P. Synak, A. Kalinov, I.-M. Strugaru, A. Etemadi, H. Yang, and C. Wojtan, “Multi-material mesh-based surface tracking with implicit topology changes,” ACM Transactions on Graphics, vol. 43, no. 4. Association for Computing Machinery, 2024. ista: Synak P, Kalinov A, Strugaru I-M, Etemadi A, Yang H, Wojtan C. 2024. Multi-material mesh-based surface tracking with implicit topology changes. ACM Transactions on Graphics. 43(4), 54. mla: Synak, Peter, et al. “Multi-Material Mesh-Based Surface Tracking with Implicit Topology Changes.” ACM Transactions on Graphics, vol. 43, no. 4, 54, Association for Computing Machinery, 2024, doi:10.1145/3658223. short: P. Synak, A. Kalinov, I.-M. Strugaru, A. Etemadi, H. Yang, C. Wojtan, ACM Transactions on Graphics 43 (2024). corr_author: '1' date_created: 2024-07-10T12:24:00Z date_published: 2024-07-01T00:00:00Z date_updated: 2026-04-07T13:02:36Z day: '01' ddc: - '004' department: - _id: GradSch - _id: ChWo doi: 10.1145/3658223 external_id: isi: - '001289270900021' file: - access_level: open_access checksum: 1917067d4b52d7729019b03560004e43 content_type: application/pdf creator: dernst date_created: 2024-07-23T06:35:15Z date_updated: 2024-07-23T06:35:15Z file_id: '17317' file_name: 2024_ACMToG_HeissSynak.pdf file_size: 48763368 relation: main_file success: 1 - access_level: open_access checksum: a4f0e293184bfa034c0c585848806b17 content_type: video/mp4 creator: akalinov date_created: 2024-07-10T12:23:44Z date_updated: 2024-07-10T12:23:44Z file_id: '17221' file_name: sdtopofixer_final.mp4 file_size: 48021463 relation: main_file success: 1 - access_level: open_access checksum: 18fc310a78ec91651148c45a8b89fa44 content_type: application/pdf creator: akalinov date_created: 2025-11-11T09:50:52Z date_updated: 2025-11-11T09:50:52Z file_id: '20633' file_name: SuperDuperTopoFixer.pdf file_size: 48639581 relation: preprint title: Authors' version of the text file_date_updated: 2025-11-11T09:50:52Z has_accepted_license: '1' intvolume: ' 43' isi: 1 issue: '4' keyword: - surface tracking - topology change - non- manifold meshes - multi-material flows - solid modeling language: - iso: eng month: '07' oa: 1 oa_version: Published Version project: - _id: 34bc2376-11ca-11ed-8bc3-9a3b3961a088 grant_number: '101045083' name: Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena publication: ACM Transactions on Graphics publication_identifier: eissn: - 1557-7368 issn: - 0730-0301 publication_status: published publisher: Association for Computing Machinery quality_controlled: '1' related_material: record: - id: '19630' relation: dissertation_contains status: public - id: '18301' relation: dissertation_contains status: public scopus_import: '1' status: public title: Multi-material mesh-based surface tracking with implicit topology changes tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 43 year: '2024' ... --- _id: '17154' abstract: - lang: eng text: We compute the deterministic approximation for mixed fluctuation moments of products of deterministic matrices and general Sobolev functions of Wigner matrices. Restricting to polynomials, our formulas reproduce recent results of Male et al. (Random Matrices Theory Appl. 11(2):2250015, 2022), showing that the underlying combinatorics of non-crossing partitions and annular non-crossing permutations continue to stay valid beyond the setting of second-order free probability theory. The formulas obtained further characterize the variance in the functional central limit theorem given in the recent companion paper (Reker in Preprint, arXiv:2204.03419, 2023). and thus allow identifying the fluctuation around the thermal value in certain thermalization problems. article_number: '10' article_processing_charge: Yes (via OA deal) article_type: original arxiv: 1 author: - first_name: Jana full_name: Reker, Jana id: e796e4f9-dc8d-11ea-abe3-97e26a0323e9 last_name: Reker citation: ama: Reker J. Fluctuation moments for regular functions of Wigner Matrices. Mathematical Physics, Analysis and Geometry. 2024;27(3). doi:10.1007/s11040-024-09483-y apa: Reker, J. (2024). Fluctuation moments for regular functions of Wigner Matrices. Mathematical Physics, Analysis and Geometry. Springer Nature. https://doi.org/10.1007/s11040-024-09483-y chicago: Reker, Jana. “Fluctuation Moments for Regular Functions of Wigner Matrices.” Mathematical Physics, Analysis and Geometry. Springer Nature, 2024. https://doi.org/10.1007/s11040-024-09483-y. ieee: J. Reker, “Fluctuation moments for regular functions of Wigner Matrices,” Mathematical Physics, Analysis and Geometry, vol. 27, no. 3. Springer Nature, 2024. ista: Reker J. 2024. Fluctuation moments for regular functions of Wigner Matrices. Mathematical Physics, Analysis and Geometry. 27(3), 10. mla: Reker, Jana. “Fluctuation Moments for Regular Functions of Wigner Matrices.” Mathematical Physics, Analysis and Geometry, vol. 27, no. 3, 10, Springer Nature, 2024, doi:10.1007/s11040-024-09483-y. short: J. Reker, Mathematical Physics, Analysis and Geometry 27 (2024). date_created: 2024-06-21T09:31:17Z date_published: 2024-06-20T00:00:00Z date_updated: 2026-04-07T13:02:12Z day: '20' ddc: - '519' department: - _id: LaEr doi: 10.1007/s11040-024-09483-y ec_funded: 1 external_id: arxiv: - '2307.11029' isi: - '001251464300001' file: - access_level: open_access checksum: 7d04318d66f765621bdcb648378d458e content_type: application/pdf creator: cchlebak date_created: 2024-06-26T11:26:42Z date_updated: 2024-06-26T11:26:42Z file_id: '17175' file_name: 2024_MathPhysAnaGeo_Reker.pdf file_size: 1327596 relation: main_file success: 1 file_date_updated: 2024-06-26T11:26:42Z has_accepted_license: '1' intvolume: ' 27' isi: 1 issue: '3' language: - iso: eng month: '06' oa: 1 oa_version: Published Version project: - _id: B67AFEDC-15C9-11EA-A837-991A96BB2854 name: IST Austria Open Access Fund - _id: 62796744-2b32-11ec-9570-940b20777f1d call_identifier: H2020 grant_number: '101020331' name: Random matrices beyond Wigner-Dyson-Mehta publication: Mathematical Physics, Analysis and Geometry publication_identifier: eissn: - 1572-9656 issn: - 1385-0172 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: record: - id: '17164' relation: dissertation_contains status: public scopus_import: '1' status: public title: Fluctuation moments for regular functions of Wigner Matrices tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 27 year: '2024' ... --- OA_place: publisher _id: '18301' abstract: - lang: eng text: Physics simulation in computer graphics can bring triangle meshes into topologically invalid states. The method in this thesis contributed to Heiss-Synak* and Kalinov* et al. [2024] who devised a non-manifold hybrid surface tracker—a surface tracker that repairs explicit non-manifold triangle meshes with the help of the implicit domain. Specifically, this thesis provides an algorithm for filling the holes that are left after removing problematic parts of the mesh. alternative_title: - ISTA Master's Thesis article_processing_charge: No author: - first_name: Arian full_name: Etemadihaghighi, Arian id: 36cea3aa-f38e-11ec-8ae0-c65ae6f6098f last_name: Etemadihaghighi citation: ama: Etemadi A. Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking. 2024. doi:10.15479/at:ista:18301 apa: Etemadi, A. (2024). Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:18301 chicago: Etemadi, Arian. “Filling the Holes of Non-Manifold Self-Intersecting Meshes for Implicit Topology Changes in Surface Tracking.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:18301. ieee: A. Etemadi, “Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking,” Institute of Science and Technology Austria, 2024. ista: Etemadi A. 2024. Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking. Institute of Science and Technology Austria. mla: Etemadi, Arian. Filling the Holes of Non-Manifold Self-Intersecting Meshes for Implicit Topology Changes in Surface Tracking. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:18301. short: A. Etemadi, Filling the Holes of Non-Manifold Self-Intersecting Meshes for Implicit Topology Changes in Surface Tracking, Institute of Science and Technology Austria, 2024. corr_author: '1' date_created: 2024-10-11T19:52:20Z date_published: 2024-10-15T00:00:00Z date_updated: 2026-04-07T13:02:36Z day: '15' ddc: - '000' degree_awarded: MS department: - _id: GradSch - _id: ChWo doi: 10.15479/at:ista:18301 file: - access_level: open_access checksum: 80fb7923e229ad9d39253d7c8a8083d0 content_type: application/pdf creator: aetemadi date_created: 2024-10-24T14:34:42Z date_updated: 2024-10-24T14:34:42Z file_id: '18469' file_name: thesis-arian-etemadi.pdf file_size: 8914218 relation: main_file success: 1 - access_level: closed checksum: 1c02586ed7d441d5ec441867650568d1 content_type: application/x-zip-compressed creator: aetemadi date_created: 2024-10-24T14:34:54Z date_updated: 2024-10-24T14:34:54Z file_id: '18470' file_name: thesis-arian-etemadi-latex-source.zip file_size: 9802650 relation: source_file file_date_updated: 2024-10-24T14:34:54Z has_accepted_license: '1' keyword: - surface tracking - non-manifold - hole-filling - topology change - multi-material - solid-modeling language: - iso: eng month: '10' oa: 1 oa_version: Published Version page: '39' publication_identifier: issn: - 2791-4585 publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '17219' relation: part_of_dissertation status: public status: public supervisor: - first_name: Christopher J full_name: Wojtan, Christopher J id: 3C61F1D2-F248-11E8-B48F-1D18A9856A87 last_name: Wojtan orcid: 0000-0001-6646-5546 title: Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking tmp: image: /images/cc_by_sa.png legal_code_url: https://creativecommons.org/licenses/by-sa/4.0/legalcode name: Creative Commons Attribution-ShareAlike 4.0 International Public License (CC BY-SA 4.0) short: CC BY-SA (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- OA_place: repository OA_type: green _id: '17047' abstract: - lang: eng text: We provide a dynamical study of a model of multiplicative perturbation of a unitary matrix introduced by Fyodorov. In particular, we identify a flow of deterministic domains that bound the spectrum with high probability, separating the outlier from the typical eigenvalues at all sub-critical timescales. These results are obtained under generic assumptions on U that hold for a variety of unitary random matrix models. article_number: '2450007' article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Guillaume full_name: Dubach, Guillaume id: D5C6A458-10C4-11EA-ABF4-A4B43DDC885E last_name: Dubach orcid: 0000-0001-6892-8137 - first_name: Jana full_name: Reker, Jana id: e796e4f9-dc8d-11ea-abe3-97e26a0323e9 last_name: Reker citation: ama: 'Dubach G, Reker J. Dynamics of a rank-one multiplicative perturbation of a unitary matrix. Random Matrices: Theory and Applications. 2024;13(2). doi:10.1142/s2010326324500072' apa: 'Dubach, G., & Reker, J. (2024). Dynamics of a rank-one multiplicative perturbation of a unitary matrix. Random Matrices: Theory and Applications. World Scientific Publishing. https://doi.org/10.1142/s2010326324500072' chicago: 'Dubach, Guillaume, and Jana Reker. “Dynamics of a Rank-One Multiplicative Perturbation of a Unitary Matrix.” Random Matrices: Theory and Applications. World Scientific Publishing, 2024. https://doi.org/10.1142/s2010326324500072.' ieee: 'G. Dubach and J. Reker, “Dynamics of a rank-one multiplicative perturbation of a unitary matrix,” Random Matrices: Theory and Applications, vol. 13, no. 2. World Scientific Publishing, 2024.' ista: 'Dubach G, Reker J. 2024. Dynamics of a rank-one multiplicative perturbation of a unitary matrix. Random Matrices: Theory and Applications. 13(2), 2450007.' mla: 'Dubach, Guillaume, and Jana Reker. “Dynamics of a Rank-One Multiplicative Perturbation of a Unitary Matrix.” Random Matrices: Theory and Applications, vol. 13, no. 2, 2450007, World Scientific Publishing, 2024, doi:10.1142/s2010326324500072.' short: 'G. Dubach, J. Reker, Random Matrices: Theory and Applications 13 (2024).' corr_author: '1' date_created: 2024-05-23T08:31:57Z date_published: 2024-04-01T00:00:00Z date_updated: 2026-04-07T13:02:12Z day: '01' department: - _id: GradSch - _id: LaEr doi: 10.1142/s2010326324500072 ec_funded: 1 external_id: arxiv: - '2212.14638' isi: - '001229295200002' intvolume: ' 13' isi: 1 issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.48550/arXiv.2212.14638' month: '04' oa: 1 oa_version: Preprint project: - _id: 62796744-2b32-11ec-9570-940b20777f1d call_identifier: H2020 grant_number: '101020331' name: Random matrices beyond Wigner-Dyson-Mehta publication: 'Random Matrices: Theory and Applications' publication_identifier: eissn: - 2010-3271 issn: - 2010-3263 publication_status: published publisher: World Scientific Publishing quality_controlled: '1' related_material: record: - id: '17164' relation: dissertation_contains status: public scopus_import: '1' status: public title: Dynamics of a rank-one multiplicative perturbation of a unitary matrix type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 13 year: '2024' ... --- OA_place: publisher _id: '17850' abstract: - lang: eng text: "Understanding the relationship between a given phenotype and its underlying genotype or genotypes is one of the most pressing challenges of biology, as it lies at the heart of not only basic understanding of evolutionary theory, but also of practical applications in medicine and bioengineering. Understanding this relationship is complicated by the ubiquitous phenomenon of epistasis, wherein mutation effects are dependent on their genetic context. Fitness landscapes — representations of phenotype as a function of genotype — are being increasingly used as a tool to study the effects and interactions of thousands of mutations, but are experimentally limited to exploring a small fraction of a protein’s theoretical sequence space. Furthermore, not all regions of said sequence space are necessarily equally informative. Thus, gene selection for landscape surveys should be carefully considered in order to maximize the usable output of necessarily limited data.\r\n\r\nIn this work, we analyzed the fitness landscapes of orthologous green fluorescent proteins from four different species, by systematically measuring the phenotype, fluorescence, of tens of thousands of mutant genotypes from each protein. These landscapes were highly heterogeneous, with some genes being mutationally robust and displaying epistasis only rarely, and others being highly epistatic and mutationally fragile. We used this data to train machine learning models to predict fluorescence from genotype. Although the training data contained almost exclusively genotypes with less than 3% sequence divergence from the original wild-type sequences, we were able to create novel, functional genotypes with up to 20% sequence divergence. Counterintuitively however, genes with high mutational robustness and rare epistasis were more difficult to introduce large numbers of mutations into, not less. This represents the first study of large-scale fitness landscapes of a protein family, and provides insights into how to approach future landscape surveys and their applications in novel protein design." acknowledged_ssus: - _id: Bio - _id: LifeSc - _id: ScienComp alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Louisa full_name: Gonzalez Somermeyer, Louisa id: 4720D23C-F248-11E8-B48F-1D18A9856A87 last_name: Gonzalez Somermeyer orcid: 0000-0001-9139-5383 citation: ama: Gonzalez Somermeyer L. Fitness landscapes of orthologous green fluorescent proteins. 2024. doi:10.15479/at:ista:17850 apa: Gonzalez Somermeyer, L. (2024). Fitness landscapes of orthologous green fluorescent proteins. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:17850 chicago: Gonzalez Somermeyer, Louisa. “Fitness Landscapes of Orthologous Green Fluorescent Proteins.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:17850. ieee: L. Gonzalez Somermeyer, “Fitness landscapes of orthologous green fluorescent proteins,” Institute of Science and Technology Austria, 2024. ista: Gonzalez Somermeyer L. 2024. Fitness landscapes of orthologous green fluorescent proteins. Institute of Science and Technology Austria. mla: Gonzalez Somermeyer, Louisa. Fitness Landscapes of Orthologous Green Fluorescent Proteins. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:17850. short: L. Gonzalez Somermeyer, Fitness Landscapes of Orthologous Green Fluorescent Proteins, Institute of Science and Technology Austria, 2024. corr_author: '1' date_created: 2024-09-06T12:57:44Z date_published: 2024-09-06T00:00:00Z date_updated: 2026-04-07T13:25:01Z day: '06' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: FyKo doi: 10.15479/at:ista:17850 ec_funded: 1 file: - access_level: open_access checksum: d3303724e8d3c91321d71bbad4062048 content_type: application/pdf creator: lgonzale date_created: 2024-09-27T10:32:33Z date_updated: 2024-09-27T10:32:33Z file_id: '18151' file_name: louisa_thesis_draft__240904b.pdf file_size: 11219837 relation: main_file - access_level: closed checksum: 22e63f7f9014dffde2af7a47e7d1d014 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: lgonzale date_created: 2024-09-27T10:34:34Z date_updated: 2024-09-27T10:34:34Z file_id: '18152' file_name: louisa_thesis_draft__240904b.docx file_size: 43338677 relation: source_file file_date_updated: 2024-09-27T10:34:34Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '89' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 26580278-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '771209' name: Characterizing the fitness landscape on population and global scales publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: link: - relation: software url: https://github.com/aequorea238/Orthologous_GFP_Fitness_Peaks record: - id: '11448' relation: part_of_dissertation status: public status: public supervisor: - first_name: Fyodor full_name: Kondrashov, Fyodor id: 44FDEF62-F248-11E8-B48F-1D18A9856A87 last_name: Kondrashov orcid: 0000-0001-8243-4694 title: Fitness landscapes of orthologous green fluorescent proteins tmp: image: /images/cc_by_nc_nd.png legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) short: CC BY-NC-ND (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- OA_place: repository OA_type: green _id: '21692' abstract: - lang: eng text: Scintillation, the process of converting high-energy radiation to detectable visible light, is pivotal in advanced technologies spanning from medical diagnostics to fundamental scientific research. Despite significant advancements toward faster and more efficient scintillators, there remains a fundamental limit arising from the intrinsic properties of scintillating materials. The scintillation process culminates in spontaneous emission of visible light, which is restricted in rate by the oscillator strength of individual emission centers. Here, we observe a novel collective emission phenomenon under X-ray excitation, breaking this limit and accelerating the emission. Our observation reveals that strong interactions between simultaneously excited coupled perovskite quantum dots can create collective radioluminescence. This effect is characterized by a spectral shift and an enhanced rate of emission, with an average lifetime of 230 ps, 14 times faster than their room temperature spontaneous emission. It has been established that such quantum dots exhibit superfluorescence under UV excitation. However, X-ray superfluorescence is inherently different, as each high-energy photon creates multiple synchronized excitation events, triggered by a photoelectron and resulting in even faster emission rates, a larger spectral shift, and a broader spectrum. This observation is consistent with a quantum-optical analysis explaining both the UV-driven and X-ray-driven effects. We use a Hanbury-Brown-Twiss g^(2) (τ) setup to analyze the temperature-dependent temporal response of these scintillators. Collective radioluminescence breaks the limit of scintillation lifetime based on spontaneous emission and could dramatically improve time-of-flight detector performance, introducing quantum enhancements to scintillation science. article_number: '2412.21101' article_processing_charge: No arxiv: 1 author: - first_name: Shaul full_name: Katznelson, Shaul last_name: Katznelson - first_name: Shai full_name: Levy, Shai last_name: Levy - first_name: Alexey full_name: Gorlach, Alexey last_name: Gorlach - first_name: Nathan full_name: Regev, Nathan last_name: Regev - first_name: Michael full_name: Birk, Michael last_name: Birk - first_name: Chen full_name: Mechel, Chen last_name: Mechel - first_name: Offek full_name: Tziperman, Offek last_name: Tziperman - first_name: Roman full_name: Schuetz, Roman last_name: Schuetz - first_name: Rotem full_name: Strassberg, Rotem last_name: Strassberg - first_name: Georgy full_name: Dosovitsky, Georgy last_name: Dosovitsky - first_name: Charles full_name: Roques-Carmes, Charles id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82 last_name: Roques-Carmes - first_name: Yehonadav full_name: Bekenstein, Yehonadav last_name: Bekenstein - first_name: Ido full_name: Kaminer, Ido last_name: Kaminer citation: ama: Katznelson S, Levy S, Gorlach A, et al. Superfluorescent scintillation from coupled perovskite quantum dots. arXiv. doi:10.48550/arXiv.2412.21101 apa: Katznelson, S., Levy, S., Gorlach, A., Regev, N., Birk, M., Mechel, C., … Kaminer, I. (n.d.). Superfluorescent scintillation from coupled perovskite quantum dots. arXiv. https://doi.org/10.48550/arXiv.2412.21101 chicago: Katznelson, Shaul, Shai Levy, Alexey Gorlach, Nathan Regev, Michael Birk, Chen Mechel, Offek Tziperman, et al. “Superfluorescent Scintillation from Coupled Perovskite Quantum Dots.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2412.21101. ieee: S. Katznelson et al., “Superfluorescent scintillation from coupled perovskite quantum dots,” arXiv. . ista: Katznelson S, Levy S, Gorlach A, Regev N, Birk M, Mechel C, Tziperman O, Schuetz R, Strassberg R, Dosovitsky G, Roques-Carmes C, Bekenstein Y, Kaminer I. Superfluorescent scintillation from coupled perovskite quantum dots. arXiv, 2412.21101. mla: Katznelson, Shaul, et al. “Superfluorescent Scintillation from Coupled Perovskite Quantum Dots.” ArXiv, 2412.21101, doi:10.48550/arXiv.2412.21101. short: S. Katznelson, S. Levy, A. Gorlach, N. Regev, M. Birk, C. Mechel, O. Tziperman, R. Schuetz, R. Strassberg, G. Dosovitsky, C. Roques-Carmes, Y. Bekenstein, I. Kaminer, ArXiv (n.d.). date_created: 2026-04-09T09:10:41Z date_published: 2024-12-30T00:00:00Z date_updated: 2026-04-13T09:48:01Z day: '30' doi: 10.48550/arXiv.2412.21101 extern: '1' external_id: arxiv: - '2412.21101' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.48550/arXiv.2412.21101' month: '12' oa: 1 oa_version: Preprint publication: arXiv publication_status: submitted scopus_import: '1' status: public title: Superfluorescent scintillation from coupled perovskite quantum dots type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository OA_type: green _id: '21686' abstract: - lang: eng text: Scintillation describes the conversion of high-energy particles into light in transparent media and finds diverse applications such as high-energy particle detection and industrial and medical imaging. This process operates on multiple timescales, with the final radiative step consisting of spontaneous emission, which can be modeled within the framework of quasi-equilibrium fluctuational electrodynamics. Scintillation can therefore be controlled and enhanced via nanophotonic effects, which has been proposed and experimentally demonstrated. Such designs have thus far obeyed Lorentz reciprocity, meaning there is a direct equivalence between scintillation emission and absorption by the scintillator. However, scintillators that do not obey Lorentz reciprocity have not been explored, even though they represent a novel platform for probing emission which is both nonequilibrium and nonreciprocal in nature. In this work, we propose to harness nonreciprocity to achieve directional control of scintillation emission, granting an additional degree of control over scintillation. Such directionality of light output is important in improving collection efficiencies along the directions where detectors are located. We present the design of a nonreciprocal scintillator using a one-dimensional magnetophotonic crystal in the Voigt configuration. Our work demonstrates the potential of controlling nonequilibrium emission such as scintillation by breaking reciprocity and expands the space of nanophotonic design for achieving such control. article_number: '2409.17002' article_processing_charge: No arxiv: 1 author: - first_name: Olivia Y. full_name: Long, Olivia Y. last_name: Long - first_name: Simo full_name: Pajovic, Simo last_name: Pajovic - first_name: Charles full_name: Roques-Carmes, Charles id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82 last_name: Roques-Carmes - first_name: Yoichiro full_name: Tsurimaki, Yoichiro last_name: Tsurimaki - first_name: Nicholas full_name: Rivera, Nicholas last_name: Rivera - first_name: Marin full_name: Soljačić, Marin last_name: Soljačić - first_name: Svetlana V. full_name: Boriskina, Svetlana V. last_name: Boriskina - first_name: Shanhui full_name: Fan, Shanhui last_name: Fan citation: ama: Long OY, Pajovic S, Roques-Carmes C, et al. Nonreciprocal scintillation using one-dimensional magneto-optical photonic crystals. arXiv. doi:10.48550/arXiv.2409.17002 apa: Long, O. Y., Pajovic, S., Roques-Carmes, C., Tsurimaki, Y., Rivera, N., Soljačić, M., … Fan, S. (n.d.). Nonreciprocal scintillation using one-dimensional magneto-optical photonic crystals. arXiv. https://doi.org/10.48550/arXiv.2409.17002 chicago: Long, Olivia Y., Simo Pajovic, Charles Roques-Carmes, Yoichiro Tsurimaki, Nicholas Rivera, Marin Soljačić, Svetlana V. Boriskina, and Shanhui Fan. “Nonreciprocal Scintillation Using One-Dimensional Magneto-Optical Photonic Crystals.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2409.17002. ieee: O. Y. Long et al., “Nonreciprocal scintillation using one-dimensional magneto-optical photonic crystals,” arXiv. . ista: Long OY, Pajovic S, Roques-Carmes C, Tsurimaki Y, Rivera N, Soljačić M, Boriskina SV, Fan S. Nonreciprocal scintillation using one-dimensional magneto-optical photonic crystals. arXiv, 2409.17002. mla: Long, Olivia Y., et al. “Nonreciprocal Scintillation Using One-Dimensional Magneto-Optical Photonic Crystals.” ArXiv, 2409.17002, doi:10.48550/arXiv.2409.17002. short: O.Y. Long, S. Pajovic, C. Roques-Carmes, Y. Tsurimaki, N. Rivera, M. Soljačić, S.V. Boriskina, S. Fan, ArXiv (n.d.). date_created: 2026-04-09T09:10:41Z date_published: 2024-09-25T00:00:00Z date_updated: 2026-04-13T10:48:09Z day: '25' doi: 10.48550/arXiv.2409.17002 extern: '1' external_id: arxiv: - '2409.17002' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2409.17002 month: '09' oa: 1 oa_version: Preprint publication: arXiv publication_status: submitted scopus_import: '1' status: public title: Nonreciprocal scintillation using one-dimensional magneto-optical photonic crystals type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository OA_type: green _id: '21685' abstract: - lang: eng text: Nonlinear optics has become the workhorse for countless applications in classical and quantum optics, from optical bistability to single photon pair generation. However, the intrinsic weakness of optical nonlinearity has meant that large input powers and weak output powers are often a necessity in nonlinear frequency conversion. Here, motivated by recent advances in using non-Hermitian photonics and gain/loss engineering to enable non-reciprocal light transport, we explore how the interplay between non-Hermiticity and optical nonlinearity leads to a fundamentally new regime of nonlinear frequency conversion. We show how non-Hermitian coupling between discrete frequency modes can result in non-reciprocal flow of energy in the frequency dimension, closely resembling the non-Hermitian skin effect (NHSE). Applying our theory to a multimode nonlinear cavity supporting cascaded nonlinear processes, we create an asymmetric infrared (IR) comb that features a ``skin'' frequency mode populated with efficiency exceeding 85\%. Furthermore, we demonstrate how three-wave mixing processes in the non-reciprocal infrared comb we generate enables terahertz (THz) generation exceeding the Manley-Rowe limit. We then show how the non-reciprocal frequency conversion is robust against cavity defects and disorder that cause random fluctuations in the dissipation rate for different modes. Moreover, in certain regimes, the nonlinear, non-Hermitian system supports stable limit cycles that can enable multimode pulsing with picosecond pulse widths and GHz repetition rates. Finally, we explore how the system can be applied to generate simultaneous IR and THz frequency combs, potentially unlocking novel applications in spectroscopy and metrology. article_number: '2409.14299' article_processing_charge: No arxiv: 1 author: - first_name: Sahil full_name: Pontula, Sahil last_name: Pontula - first_name: Sachin full_name: Vaidya, Sachin last_name: Vaidya - first_name: Charles full_name: Roques-Carmes, Charles id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82 last_name: Roques-Carmes - first_name: Shiekh Zia full_name: Uddin, Shiekh Zia last_name: Uddin - first_name: Marin full_name: Soljacic, Marin last_name: Soljacic - first_name: Yannick full_name: Salamin, Yannick last_name: Salamin citation: ama: Pontula S, Vaidya S, Roques-Carmes C, Uddin SZ, Soljacic M, Salamin Y. Non-reciprocal frequency conversion in a multimode nonlinear system. arXiv. doi:10.48550/arXiv.2409.14299 apa: Pontula, S., Vaidya, S., Roques-Carmes, C., Uddin, S. Z., Soljacic, M., & Salamin, Y. (n.d.). Non-reciprocal frequency conversion in a multimode nonlinear system. arXiv. https://doi.org/10.48550/arXiv.2409.14299 chicago: Pontula, Sahil, Sachin Vaidya, Charles Roques-Carmes, Shiekh Zia Uddin, Marin Soljacic, and Yannick Salamin. “Non-Reciprocal Frequency Conversion in a Multimode Nonlinear System.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2409.14299. ieee: S. Pontula, S. Vaidya, C. Roques-Carmes, S. Z. Uddin, M. Soljacic, and Y. Salamin, “Non-reciprocal frequency conversion in a multimode nonlinear system,” arXiv. . ista: Pontula S, Vaidya S, Roques-Carmes C, Uddin SZ, Soljacic M, Salamin Y. Non-reciprocal frequency conversion in a multimode nonlinear system. arXiv, 2409.14299. mla: Pontula, Sahil, et al. “Non-Reciprocal Frequency Conversion in a Multimode Nonlinear System.” ArXiv, 2409.14299, doi:10.48550/arXiv.2409.14299. short: S. Pontula, S. Vaidya, C. Roques-Carmes, S.Z. Uddin, M. Soljacic, Y. Salamin, ArXiv (n.d.). date_created: 2026-04-09T09:10:41Z date_published: 2024-09-22T00:00:00Z date_updated: 2026-04-13T10:49:12Z day: '22' doi: 10.48550/arXiv.2409.14299 extern: '1' external_id: arxiv: - '2409.14299' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2409.14299 month: '09' oa: 1 oa_version: Preprint publication: arXiv publication_status: submitted scopus_import: '1' status: public title: Non-reciprocal frequency conversion in a multimode nonlinear system type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository OA_type: green _id: '21689' abstract: - lang: eng text: Metasurfaces -- ultrathin structures composed of subwavelength optical elements -- have revolutionized light manipulation by enabling precise control over electromagnetic waves' amplitude, phase, polarization, and spectral properties. Concurrently, computational imaging leverages algorithms to reconstruct images from optically processed signals, overcoming limitations of traditional imaging systems. This review explores the synergistic integration of metaoptics and computational imaging, "computational metaoptics," which combines the physical wavefront shaping ability of metasurfaces with advanced computational algorithms to enhance imaging performance beyond conventional limits. We discuss how computational metaoptics addresses the inherent limitations of single-layer metasurfaces in achieving multifunctionality without compromising efficiency. By treating metasurfaces as physical preconditioners and co-designing them with reconstruction algorithms through end-to-end (inverse) design, it is possible to jointly optimize the optical hardware and computational software. This holistic approach allows for the automatic discovery of optimal metasurface designs and reconstruction methods that significantly improve imaging capabilities. Advanced applications enabled by computational metaoptics are highlighted, including phase imaging and quantum state measurement, which benefit from the metasurfaces' ability to manipulate complex light fields and the computational algorithms' capacity to reconstruct high-dimensional information. We also examine performance evaluation challenges, emphasizing the need for new metrics that account for the combined optical and computational nature of these systems. Finally, we identify new frontiers in computational metaoptics which point toward a future where computational metaoptics may play a central role in advancing imaging science and technology. article_number: '2411.09133' article_processing_charge: No arxiv: 1 author: - first_name: Charles full_name: Roques-Carmes, Charles id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82 last_name: Roques-Carmes - first_name: Kai full_name: Wang, Kai last_name: Wang - first_name: Yuanmu full_name: Yang, Yuanmu last_name: Yang - first_name: Arka full_name: Majumdar, Arka last_name: Majumdar - first_name: Zin full_name: Lin, Zin last_name: Lin citation: ama: Roques-Carmes C, Wang K, Yang Y, Majumdar A, Lin Z. Computational metaoptics for imaging. arXiv. doi:10.48550/arXiv.2411.09133 apa: Roques-Carmes, C., Wang, K., Yang, Y., Majumdar, A., & Lin, Z. (n.d.). Computational metaoptics for imaging. arXiv. https://doi.org/10.48550/arXiv.2411.09133 chicago: Roques-Carmes, Charles, Kai Wang, Yuanmu Yang, Arka Majumdar, and Zin Lin. “Computational Metaoptics for Imaging.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2411.09133. ieee: C. Roques-Carmes, K. Wang, Y. Yang, A. Majumdar, and Z. Lin, “Computational metaoptics for imaging,” arXiv. . ista: Roques-Carmes C, Wang K, Yang Y, Majumdar A, Lin Z. Computational metaoptics for imaging. arXiv, 2411.09133. mla: Roques-Carmes, Charles, et al. “Computational Metaoptics for Imaging.” ArXiv, 2411.09133, doi:10.48550/arXiv.2411.09133. short: C. Roques-Carmes, K. Wang, Y. Yang, A. Majumdar, Z. Lin, ArXiv (n.d.). date_created: 2026-04-09T09:10:41Z date_published: 2024-11-14T00:00:00Z date_updated: 2026-04-13T09:53:49Z day: '14' doi: 10.48550/arXiv.2411.09133 extern: '1' external_id: arxiv: - '2411.09133' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2411.09133 month: '11' oa: 1 oa_version: Preprint publication: arXiv publication_status: submitted scopus_import: '1' status: public title: Computational metaoptics for imaging type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository OA_type: green _id: '21690' abstract: - lang: eng text: Many quantum systems exhibit high sensitivity to their initial conditions, where microscopic quantum fluctuations can significantly influence macroscopic observables. Understanding how quantum states may influence the behavior of nonlinear dynamic systems may open new avenues in controlling light-matter interactions. To explore this issue, we analyze the sensitivity of a fundamental quantum optical process - parametric oscillation - to quantum initializations. Focusing on optical parametric oscillators (OPOs), we demonstrate that the quantum statistics of arbitrary initial states are imprinted in the early-stage dynamics and can persist in the steady-state probabilities. We derive the "quantum sensitivity" of parametric oscillators, linking the initial quantum state to the system's steady-state outcomes, highlighting how losses and parametric gain govern the system's quantum sensitivity. Moreover, we show that these findings extend beyond OPOs to a broader class of nonlinear systems, including Josephson junction based superconducting circuits. Our work opens the way to a new class of experiments that can test the sensitivity of macroscopic systems to quantum initial conditions and offers a pathway for controlling systems with quantum degrees of freedom. article_number: :2412.02887 article_processing_charge: No arxiv: 1 author: - first_name: Alex full_name: Gu, Alex last_name: Gu - first_name: Jamison full_name: Sloan, Jamison last_name: Sloan - first_name: Charles full_name: Roques-Carmes, Charles id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82 last_name: Roques-Carmes - first_name: Seou full_name: Choi, Seou last_name: Choi - first_name: Eric I. full_name: Rosenthal, Eric I. last_name: Rosenthal - first_name: Michael full_name: Horodynski, Michael last_name: Horodynski - first_name: Yannick full_name: Salamin, Yannick last_name: Salamin - first_name: Jelena full_name: Vučković, Jelena last_name: Vučković - first_name: Marin full_name: Soljačić, Marin last_name: Soljačić citation: ama: Gu A, Sloan J, Roques-Carmes C, et al. Quantum sensitivity of parametric oscillators. arXiv. doi:10.48550/arXiv.2412.02887 apa: Gu, A., Sloan, J., Roques-Carmes, C., Choi, S., Rosenthal, E. I., Horodynski, M., … Soljačić, M. (n.d.). Quantum sensitivity of parametric oscillators. arXiv. https://doi.org/10.48550/arXiv.2412.02887 chicago: Gu, Alex, Jamison Sloan, Charles Roques-Carmes, Seou Choi, Eric I. Rosenthal, Michael Horodynski, Yannick Salamin, Jelena Vučković, and Marin Soljačić. “Quantum Sensitivity of Parametric Oscillators.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2412.02887. ieee: A. Gu et al., “Quantum sensitivity of parametric oscillators,” arXiv. . ista: Gu A, Sloan J, Roques-Carmes C, Choi S, Rosenthal EI, Horodynski M, Salamin Y, Vučković J, Soljačić M. Quantum sensitivity of parametric oscillators. arXiv, :2412.02887. mla: Gu, Alex, et al. “Quantum Sensitivity of Parametric Oscillators.” ArXiv, :2412.02887, doi:10.48550/arXiv.2412.02887. short: A. Gu, J. Sloan, C. Roques-Carmes, S. Choi, E.I. Rosenthal, M. Horodynski, Y. Salamin, J. Vučković, M. Soljačić, ArXiv (n.d.). date_created: 2026-04-09T09:10:41Z date_published: 2024-12-03T00:00:00Z date_updated: 2026-04-13T09:52:34Z day: '03' doi: 10.48550/arXiv.2412.02887 extern: '1' external_id: arxiv: - '2412.02887' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2412.02887 month: '12' oa: 1 oa_version: Preprint publication: arXiv publication_status: submitted scopus_import: '1' status: public title: Quantum sensitivity of parametric oscillators type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ...