@phdthesis{20991, abstract = {Rapid local adaptation to new environments is critical for species persistence, especially in introduced populations. The evolutionary success of these populations is fundamentally dictated by the organization of genetic variation—the genomic architecture—in the face of severe demographic constraints, such as the founder effects and genetic bottlenecks that frequently accompany colonization. A central question in evolutionary biology is whether rapid adaptation relies on major-effect loci, such as chromosomal inversions, or on many small-effect loci dispersed across the genome. Furthermore, the genomic architecture strongly influences the extent to which evolutionary outcomes are predictable. Using introduced populations of the marine snail, Littorina saxatilis, as a model, this thesis investigates how genetic variation and genomic structure drive adaptation following introduction. We employed a population genomics approach on experimentally and accidentally introduced populations to dissect the specific genomic features that underpin divergence in newly colonized environments. In Chapter 2, we tested the predictability of local adaptation through an uncommon 30-year transplant experiment in nature. By distinguishing allele and chromosomal inversion frequency changes from neutral expectations, we found that evolutionary change was highly predictable at the macro-scale (phenotypes and chromosomal inversions), but less robust at the level of individual collinear loci. This result demonstrates that evolution can be predictable when a population possesses sufficient standing genetic variation (SGV), with chromosomal inversions acting as key integrated units that facilitate a rapid response to selection. Building on this, Chapter 3 applied whole-genome sequencing to three accidentally introduced populations (Venice, San Francisco, and Redwood City) to investigate their likely source and genomic patterns of divergence. We identified genomic regions of remarkable divergence potentially associated with local adaptation, and likely fuelled by SGV, while explicitly acknowledging the difficulty in disentangling selection signals from the genome-wide effects of demographic processes. Furthermore, we found that the divergence patterns relied extensively on the collinear genome in these introduced populations, and less clearly on the chromosomal inversions. This observation contrasts with local adaptation observed in the experimental system that relied on both collinear loci and highly selected chromosomal inversions, highlighting how demographic history and genomic architecture influence the detectable signature of local adaptation. A major limitation to conducting large-scale comparative evolutionary studies is the lack of data standardization, which prevents the integration of community knowledge and high-resolution environmental and genetic data. Chapter 4 addresses this by developing a community database for the Littorina system. This platform implements standardized protocols for the integration of diverse phenotypic and environmental data from multiple Littorina species. Likewise, the platform also centralizes the availability of associated genomic data through links to external repositories. This database represents a crucial tool to test complex, large-scale evolutionary hypotheses. Collectively, this thesis strongly reinforces the fundamental importance of SGV as the raw material for successful local adaptation, a conclusion supported by evidence in both experimental and accidental introductions. Furthermore, this work highlights the critical role of the genomic architecture—specifically chromosomal inversions—in driving the predictability and effectiveness of adaptive responses. Our findings underscore how the interplay between SGV and genomic architecture dictates the trajectory and detectability of evolution in colonizing populations, while simultaneously providing a necessary tool to advance comparative evolutionary genomics in emerging model organisms.}, author = {Garcia Castillo, Diego Fernando}, isbn = {978-3-99078-077-0}, issn = {2663-337X}, pages = {199}, publisher = {Institute of Science and Technology Austria}, title = {{The genomic architecture of local adaptation in introduced populations}}, doi = {10.15479/AT-ISTA-20991}, year = {2026}, } @phdthesis{22684, abstract = {Contact electrification (CE) is a simple yet elusive phenomenon that occurs when two materials come into contact and separate, leaving behind net electrical charge. Despite its ubiquity, the microscopic origin of CE remains unclear. In this thesis, we investigate CE from three complementary perspectives: developing a quantitative method to measure charge at the nanoscale, exploring the dynamic behavior of charge on insulating surfaces, and uncovering the role of mechanical history in forming a triboelectric series. In the first part, we establish a rigorous framework for converting qualitative Kelvin probe force microscopy (KPFM) voltage maps into quantitative charge density distributions. Using finite element method (FEM) simulations, we determine the point-spread function of the KPFM tip–sample geometry and demonstrate that the true surface charge can be reconstructed by numerical deconvolution. This procedure enables the recovery of both the magnitude and sign of charge density with high fidelity, resolving nanoscale features that are otherwise obscured. Applying the method to contact-charged SiO$_2$ surfaces, we show that existing analytical approximations, such as parallel plate or spherical models, can miscalculate charge magnitude by orders of magnitude. Our hybrid FEM/KPFM approach therefore provides a fast and general method to convert qualitative KPFM signals into quantitative charge data, enabling nanoscale charge mapping under realistic experimental conditions. In the second part, we study the temporal stability of CE-induced charges and identify the key material factors that determine whether KPFM can capture meaningful charge patterns. Through time-resolved experiments combining a custom-built transfer system with both microscopic and macroscopic measurements, we demonstrate that only the best insulators, such as SiO$_2$, preserve CE charge long enough for stationary imaging. For less conductive polymers, such as PDMS, charge decays within the duration of a single KPFM scan due to bulk conduction. Using a simple capacitor-based model, we reproduce the observed decay dynamics and confirm that the transferred charge decays characteristic to the sample's bulk conductivity. Further, we always observe homogeneous charge transfer. In the third part, we address the question: can we form a triboelectric series with identical materials? Using controlled repetitive contact experiments, we show that nominally identical materials can progressively order themselves into a triboelectric series, where surfaces with more contact history charge negatively relative to fresher ones. By constructing a minimal model based on this ``contact bias'', we replicate the evolution from random to ordered charging observed in experiments. Supporting surface analyses, including atomic force microscopy, reveal that repeated contact induces nanoscale morphological changes, suggesting a mechanism tightly coupled to mechanical strain. These results highlight the crucial role of surface history and nanoscale mechanics in dictating charge transfer, motivating further exploration of mechanisms such as mechanochemical bond cleavage and flexoelectric polarization.}, author = {Pertl, Felix}, isbn = {978-3-99078-083-1}, issn = {2663-337X}, pages = {107}, publisher = {Institute of Science and Technology Austria}, title = {{Experimental probing of nanoscale charge features and surface morphology changes during tribocharging}}, doi = {10.15479/AT-ISTA-22684}, year = {2026}, } @article{17437, abstract = {We prove that the zero-fiber of the moment map of a totally negative quiver has rational singularities. Our proof consists in generalizing dimension bounds on jet spaces of this fiber, which were introduced by Budur. We also transfer the rational singularities property to other moduli spaces of objects in 2-Calabi-Yau categories, based on recent work of Davison. This has interesting arithmetic applications on quiver moment maps and moduli spaces of objects in 2-Calabi-Yau categories. First, we generalize results of Wyss on the asymptotic behaviour of counts of jets of quiver moment maps over finite fields. Moreover, we interpret the limit of counts of jets on a given moduli space as its p-adic volume under a canonical measure analogous to the measure built by Carocci, Orecchia and Wyss on certain moduli spaces of coherent sheaves.}, author = {Vernet, Tanguy}, issn = {1531-586X}, journal = {Transformation Groups}, pages = {1047--1083}, publisher = {Springer Nature}, title = {{Rational singularities for moment maps of totally negative quivers}}, doi = {10.1007/s00031-024-09873-0}, volume = {31}, year = {2026}, } @article{22247, abstract = {A linearly ordered (LO) k-colouring of a hypergraph is a colouring of its vertices with colours 1, …, k such that each edge contains a unique maximal colour. Deciding whether an input hypergraph admits LO k-colouring with a fixed number of colours is NP-complete (and in the special case of graphs, LO colouring coincides with the usual graph colouring). Here, we investigate the complexity of approximating the “linearly ordered chromatic number” of a hypergraph. We prove that the following promise problem is NP-complete: Given a 3-uniform hypergraph, distinguish between the case that it is LO 3-colourable, and the case that it is not even LO 4-colourable. We prove this result by a combination of algebraic, topological, and combinatorial methods, building on and extending a topological approach for studying approximate graph colouring introduced by Krokhin, Opršal, Wrochna, and Živný (2023).}, author = {Filakovský, Marek and Nakajima, Tamio Vesa and Opršal, Jakub and Tasinato, Gianluca and Wagner, Uli}, issn = {1942-3462}, journal = {ACM Transactions on Computation Theory}, keywords = {Constraint satisfaction problem, hypergraph colouring, promise problem, topological methods}, number = {2}, publisher = {Association for Computing Machinery}, title = {{Hardness of linearly ordered 4-colouring of 3-colourable 3-uniform hypergraphs}}, doi = {10.1145/3779121}, volume = {18}, year = {2026}, } @article{19860, abstract = {An eight-partition of a finite set of points (respectively, of a continuous mass distribution) in R^3 consists of three planes that divide the space into 8 octants, such that each open octant contains at most 1/8 of the points (respectively, of the mass). In 1966, Hadwiger showed that any mass distribution in R^3 admits an eight-partition; moreover, one can prescribe the normal direction of one of the three planes. The analogous result for finite point sets follows by a standard limit argument. We prove the following variant of this result: any mass distribution (or point set) in R^3 admits an eight-partition for which the intersection of two of the planes is a line with a prescribed direction. Moreover, we present an efficient algorithm for calculating an eight-partition of a set of n points in R^3 (with prescribed normal direction of one of the planes) in time O(n^7/3). A preliminary version of this work appeared in SoCG’24 (Aronov et al., 40th International Symposium on Computational Geometry, 2024).}, author = {Aronov, Boris and Basit, Abdul and Ramesh, Indu and Tasinato, Gianluca and Wagner, Uli}, issn = {1432-0444}, journal = {Discrete & Computational Geometry}, pages = {1331--1355}, publisher = {Springer Nature}, title = {{Eight-partitioning points in 3D, and efficiently too}}, doi = {10.1007/s00454-025-00739-0}, volume = {75}, year = {2026}, } @article{21763, abstract = {Reactive oxygen species (ROS) have been implicated in multiple signaling processes in plants, but the underlying mechanisms and roles remain enigmatic. In this study, we developed a method of live imaging of apoplastic ROS at the root surface. Distinct signals, including auxin, extracellular adenosine triphosphate, and rapid alkalinization factor 1 peptide, induce cytosolic calcium transients and apoplastic ROS bursts. Genetic and optogenetic manipulations of Arabidopsis identified calcium transients as necessary and sufficient for ROS bursts through activation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases RBOHC and RBOHF. Apoplastic ROS bursts are not required, but they do limit gravity-induced root bending. Root bending is sensed by the stretch-activated calcium channel MCA1, leading to NADPH oxidase activation. The resulting ROS production stiffens cell walls to facilitate soil penetration. Apoplastic ROS thus provides a means to balance tissue flexibility and stiffness to navigate soil.}, author = {Kulich, Ivan and Vladimirtsev, Dmitrii and Randuch, Marek and Gao, Shiqiang and Citterico, Matteo and Konrad, Kai R. and Nagel, Georg and Wrzaczek, Michael and Cascaro, Léa and Vinet, Pauline and Durand, Pauline and Asnacios, Atef and Verma, Lokesh and Bennett, Malcolm J. and Pandey, Bipin K. and Friml, Jiří}, issn = {1095-9203}, journal = {Science}, number = {6795}, pages = {296--300}, publisher = {AAAS}, title = {{Calcium-triggered apoplastic ROS bursts balance gravity and mechanical signals for soil navigation}}, doi = {10.1126/science.adu8197}, volume = {392}, year = {2026}, } @phdthesis{23145, author = {Randuch, Marek}, issn = {2663-337X}, pages = {289}, publisher = {Institute of Science and Technology Austria}, title = {{Fast growth responses in plants: Growth regulation and phospho-proteomic }}, doi = {10.15479/AT-ISTA-23145}, year = {2026}, } @unpublished{23175, abstract = {Plants must continually balance growth with arrest, especially under stress. Auxin signaling acts as a central regulatory hub in this process, yet the mechanisms that dynamically tune early auxin signalling in real time remain unknown. Here, we used the light-gated, Ca2+-permeable Channelrhodopsin 2 variant XXM2.0 to optogenetically impose defined Ca2+ signatures on Arabidopsis root cells. Repetitive light activation triggered cytosolic Ca2+ signals that in turn suppressed auxin-induced membrane depolarization and Ca2+ transients. Moreover, prolonged optogenetic Ca2+ stimulation affects auxin-responsive transcriptional reprogramming. As phenotypic output, reversible inhibition of root growth by suppressing cell division and elongation was observed. We further identify a candidate CaM7–CNGC14 module that likely mediates Ca2+-dependent gating of early auxin signalling. Our study thus introduces a synthetic biology approach to decompose calcium–auxin crosstalk in plant cells, and demonstrates that optogenetically imposed cytosolic Ca2+ signals act as dynamic regulators of auxin susceptibility in roots.}, author = {Song, Huifang and Baudon, Angel and Freund, Matthias and Randuch, Marek and Pěnčík, Aleš and Ondřej, Novák and He, Zhaohui and Kaufmann, Kerstin and Li, Nan and Gilliham, Matthew and Friml, Jiří and Hedrich, Rainer and Huang, Shouguang}, booktitle = {bioRxiv}, title = {{Ca2+ signature gates early auxin signaling in Arabidopsis roots}}, doi = {10.1101/2025.10.04.680446}, year = {2026}, } @inproceedings{23197, abstract = {We develop a quantum theory of light-matter interactions in 229Th nanophotonic resonators pumped via the optonuclear quadrupolar effect, predicting detectable photon fluxes with realistic platforms and revealing how collective dynamics shape the future nuclear clock performance.}, author = {Mamian, Karen and De Haan, Jan and Bi, Toby and Dubey, Swadheen and Kazakov, Georgy A. and Beeks, Kjeld and Marquardt, Christoph and Kraemer, Sandro and Pereira, Lino M.C. and Del’Haye, Pascal and Van Gasse, Kasper and Schumm, Thorsten and Roques-Carmes, Charles}, booktitle = {CLEO Fundamental Science Proceedings}, isbn = {9781957171586}, location = {Long Beach, CA, United States}, publisher = {Optica Publishing Group}, title = {{Collective optonuclear cavity quantum electrodynamics in 229Th nanophotonic resonators}}, doi = {10.1364/CLEO_FS.2026.FTU1B.4}, year = {2026}, } @article{21983, abstract = {Promoters and enhancers are cis-regulatory elements (CREs), DNA sequences that bind transcription factor (TF) proteins to up- or down-regulate target genes. Decades-long efforts yielded TF-DNA interaction models that predict how strongly an individual TF binds arbitrary DNA sequences and how individual binding events on the CRE combine to affect gene expression. These insights can be synthesized into a global, biophysically realistic, and quantitative genotype–phenotype map for gene regulation, a ‘holy grail’ for the application of evolutionary theory. A global map provides a rare opportunity to simulate the long-term evolution of regulatory sequences and pose several fundamental questions: How long does it take to evolve CREs de novo? How many non-trivial regulatory functions exist in sequence space? How connected are they? For which regulatory architecture is CRE evolution most rapid and evolvable? In this article, the first of a two-part series, we briefly review the pertinent modeling and simulation efforts for a unique system that enables close, quantitative, and mechanistic links between biophysics, as well as systems, synthetic, and evolutionary biology.}, author = {Mascolo, Elia and Körei, Reka E and Herrera-Álvarez, Santiago and Guet, Calin C and Crocker, Justin and Tkačik, Gašper}, issn = {1879-0380}, journal = {Current Opinion in Genetics & Development}, publisher = {Elsevier}, title = {{Long-term evolution of regulatory DNA sequences. Part 1: Simulations on global, biophysically-realistic genotype–phenotype maps}}, doi = {10.1016/j.gde.2026.102483}, volume = {99}, year = {2026}, } @article{23198, abstract = {Small RNAs (sRNAs) are widespread across diverse flowering plant species and play important roles regulating reproduction and environmental responses. However, how sRNAs exert their function is largely unknown, likely due to their typical origin in non-genic regions, the lack of distinct gene targets, and the sparse characterization of their associated Argonaute (AGO) effector proteins. Here we show that Arabidopsis male reproductive sRNAs associate with AGO4, 5, 6 and 9, all of which are enriched in meiocytes along with RNA Polymerase V (Pol V). This enables these sRNAs to methylate loci with imperfect sequence homology. AGO4, AGO6 and AGO9 predominantly load 24-nucleotide (nt) Pol IV-derived sRNAs and mediate DNA methylation in meiocytes in a dosage-dependent manner. Despite closer homology to microRNA-associated AGO1 and AGO10, AGO5 primarily binds CLSY3- and Pol IV-derived 21-24 nt sRNAs. Transcriptomic and methylomic analyses of meiocytes from single and compound ago mutants demonstrate distinct yet complementary roles of AGO4/6/9 and AGO5 in regulating protein-coding genes and silencing transposons in the germline. These molecular disruptions are accompanied by significant meiotic defects. Together, our findings reveal how AGO4/6/9-mediated DNA methylation and AGO5, likely acting through post-transcriptional gene silencing, work together to promote male germline development.}, author = {Long, Jincheng and Yang, Chao and Xu, Shujuan and De Jaeger-Braet, Joke G and She, Wenjing and Ono, Seijiro and Walker, James and de Souza Vieira, Ygor and Schnittger, Arp and Feng, Xiaoqi}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Multiple Argonaute complexes orchestrate epigenetic silencing in the Arabidopsis germline}}, doi = {10.1038/s41467-026-77326-1}, volume = {17}, year = {2026}, } @article{23200, abstract = {We investigate the low-ionization electron density in the interstellar medium (ISM) of galaxies across 0 < z < 8, derived with the [O II] λλ3727, 3730 and [S II] λλ6718, 6733 doublets, using both deep JWST/NIRCam/grism and NIRSpec/MSA spectroscopy. Along with ancillary density samples from the literature at 0 < z < 6, we assemble three samples containing a total of 703 galaxies spanning 3.7 < z < 7.8 at 〈z〉 ∼ 5.6; 691 galaxies in the luminosity-complete NIRCam/grism programs CONGRESS and FRESCO at 〈z〉 ∼ 4.3 and ∼5.3, respectively; and 12 galaxies with high-resolution NIRSpec/MSA spectra from the GO 1871 and GLASS programs. We find median electron densities of ne[S II] = + 463 203 cm 281 3 for CONGRESS, ne[S II] = + 301 206 cm 388 3 for FRESCO, and ne[O II] = + 202 102 cm 145 3 for the NIRSpec/MSA sample. The median low-ionization ne increases from z = 0 to 4, in agreement with previous studies and those using JWST observations. However, beyond z ∼ 4 median ne begins to deviate from a monotonically increasing evolution with z. We find a positive, but shallow, correlation between O32 (a proxy for the ionization parameter) and ne, while also confirming a positive correlation between O32 and z. We suggest that these trends are possibly due to an evolving ISM gas density and ionization structure, and propose a toy model where the gas clumping evolves with z to explain the observed density and ionization variations.}, author = {Stephenson, Mabel G. and Chisholm, John and Saldana-Lopez, A. and Matthee, Jorryt J and Henry, Alaina and Naidu, Rohan P. and Flury, Sophia R. and Hutchison, Taylor A. and Finkelstein, Steven L. and Guseva, Natalia G. and Izotov, Yuri I. and Marques-Chaves, Rui and Oesch, Pascal A. and Reddy, Naveen A. and Schaerer, Daniel}, issn = {1538-4357}, journal = {The Astrophysical Journal}, number = {2}, publisher = {IOP Publishing}, title = {{The evolution of low-ionization electron densities in galaxies across cosmic epochs}}, doi = {10.3847/1538-4357/ae9eb7}, volume = {1010}, year = {2026}, } @article{23199, abstract = {The physics governing the morphology of radio-loud active galactic nucleus (AGN) jets is not fully understood. We investigate how magnetization, flickering jet power and the interplay between them affects the morphology of radio galaxies. We present a grid of relativistic magnetohydrodynamic simulations using the pluto code covering constant and variable jets with two levels of magnetization. We find that the constant high-magnetization jets can lead to highly asymmetrical cocoon morphologies, while the variable high-magnetization jet can exhibit a broken morphology, caused by a discontinuous jet beam. Our work highlights the importance of magnetization and variability on the stability and resulting morphology of radio-loud AGN jets, suggesting both are significant factors in addition to jet power or environment. Furthermore, we show that the interaction between magnetization and variability can lead to the development of localized kink instabilities along the jet beam. Finally, we discuss the effects of hydrodynamic mixing in low-magnetization jets and the role of viewing-angle dependence in comparisons between our simulations and observed sources. To facilitate this comparison we present a library of simulated radio images at different times in the simulations and from various viewing angles, which highlight a diverse set of complex morphologies.}, author = {Elley, Emma L and Matthews, James H and Whitehead, Henry William and Cooper, Alex J}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {4}, publisher = {Oxford University Press}, title = {{The impact of flickering variability and magnetization on the dynamics, stability, and morphology of radio-loud AGN jets}}, doi = {10.1093/mnras/stag1798}, volume = {552}, year = {2026}, } @inproceedings{23196, abstract = {We introduce an experimental realization of the measurement, processing, and generation of partially coherent light on a photonic chip. This device relies on self-configuring networks optimized sequentially to learn the coherency matrix of input light.}, author = {Mor, Paul Alexis and Kroo, Annie R. and Valdez, Carson G. and Šimić, Marko and Karnieli, Aviv and Cavicchioli, Gabriele and Sun, Zhanghao and Grimaldi, Vittorio and Fan, Shanhui and Solgaard, Olav and Miller, David A.B. and Roques-Carmes, Charles}, booktitle = {CLEO Science and Innovations Proceedings}, isbn = {9781957171586}, location = {Long Beach, CA, United States}, publisher = {Optica Publishing Group}, title = {{Variational processing of partially coherent light in a photonic integrated circuit}}, doi = {10.1364/CLEO_SI.2026.STU2F.1}, year = {2026}, } @article{18706, abstract = {We prove discrete-to-continuum convergence for dynamical optimal transport on Zd -periodic graphs with cost functional having linear growth at infinity. This result provides an answer to a problem left open by Gladbach, Kopfer, Maas, and Portinale (Calc Var Partial Differential Equations 62(5), 2023), where the convergence behaviour of discrete boundary-value dynamical transport problems is proved under the stronger assumption of superlinear growth. Our result extends the known literature to some important classes of examples, such as scaling limits of 1 -Wasserstein transport problems. Similarly to what happens in the quadratic case, the geometry of the graph plays a crucial role in the structure of the limit cost function, as we discuss in the final part of this work, which includes some visual representations.}, author = {Portinale, Lorenzo and Quattrocchi, Filippo}, issn = {1469-4425}, journal = {European Journal of Applied Mathematics}, keywords = {optimal transport, discrete-to-continuum, homogenisation, linear growth, gamma-convergence}, number = {3}, pages = {614--642}, publisher = {Cambridge University Press}, title = {{Discrete-to-continuum limits of optimal transport with linear growth on periodic graphs}}, doi = {10.1017/s0956792524000810}, volume = {37}, year = {2026}, } @phdthesis{21423, abstract = {Biological systems, such as cytoskeletal filaments and multicellular collectives, exhibit rich self-organization driven by their intrinsic activity and physical constraints. Across scales, geometry plays a central role: the shape of active units and the structure of their environment strongly influence how order emerges in these far-from-equilibrium systems. In this thesis, we combine minimal active-matter models with bottom-up in vitro experiments to identify the principles by which geometry and activity shape collective behavior in biological matter. At the subcellular scale, we investigate how the physical properties of chiral FtsZ filaments govern their large-scale organization. Using a mesoscopic model validated by reconstituted filament assays, we show that filament shape, intrinsic curvature, and flexibility, together with activity-driven straightening, determine whether filaments form chiral rings, polar bands, or nematic-like states. Our model shows that small changes in filament mechanics produce large shifts in collective structures, revealing how the geometry of individual filaments amplifies through activity to control patterns relevant for bacterial cytokinesis. At the cellular scale, we examine how geometry of the external environment influences collective cancer cell migration. Experiments in controlled microfabricated obstacle environments demonstrate that geometric disorder alone can induce a transition from collective to single-cell invasion. A minimal model of active particles in disordered geometries reproduces these effects, demonstrating that cell dissemination results both from local geometrical constraints and a global integration of spatial disorder over time. Surprisingly, this transition is accompanied by a change in the universality class of interface dynamics, revealing that cell-environment interactions can shift the collective behavior of an invasive front purely through mechanics. In the last system, we study how cell-intrinsic geometry and chirality affect collective motion in confined and unconfined settings. Using a minimal model inspired by in vitro experiments, we analyze motile cells that exhibit persistent rotation due to intrinsic left-right asymmetry. In circular confinement, this simplified chiral model reproduces several experimentally observed features within specific parameter regimes. At high densities in unconfined environments, however, intrinsic chirality becomes masked even before the onset of the jamming transition. These results show that single-cell geometric asymmetry does not necessarily translate into large-scale chiral flows, offering new insight into how forces and symmetries shape collective motion in dense cellular systems. Overall, this work uncovers how geometric constraints – embedded in the intrinsic architecture of an active filament or encoded in the complexity of a microenvironment couple to active forces to generate different classes of complex behaviors. }, author = {Dunajova, Zuzana}, isbn = {978-3-99078-076-3}, issn = {2663-337X}, pages = {110}, publisher = {Institute of Science and Technology Austria}, title = {{Geometry-driven self-organization of migrating cells and chiral filaments}}, doi = {10.15479/AT-ISTA-21423}, year = {2026}, } @misc{21439, abstract = {These files contain supplementary movies accompanying the PhD thesis “Geometry-driven self-organization of migrating cells and chiral filaments” by Zuzana Dunajova (2026). The videos provide additional visual material supporting the experiments and results described in the thesis.}, author = {Dunajova, Zuzana}, publisher = {Institute of Science and Technology Austria}, title = {{Supplementary movies to PhD thesis “Geometry-driven self-organization of migrating cells and chiral filaments”}}, doi = {10.15479/AT-ISTA-21439}, year = {2026}, } @inproceedings{22007, abstract = {Truncation of cryptographic outputs is a technique that was recently introduced in Baldimtsi et al. [Foteini Baldimtsi et al., 2022]. The general idea is to try out many inputs to some cryptographic algorithm until the output (e.g. a public-key or some hash value) falls into some sparse set and thus can be compressed: by trying out an expected 2^k different inputs one will find an output that starts with k zeros. Using such truncation one can for example save substantial gas fees on Blockchains where storing values is very expensive. While [Foteini Baldimtsi et al., 2022] show that truncation preserves the security of the underlying primitive, they only consider a setting without preprocessing. In this work we show that lower bounds on the time-space tradeoff for inverting random functions and permutations also hold with truncation, except for parameters ranges where the bound fails to hold for "trivial" reasons. Concretely, it’s known that any algorithm that inverts a random function or permutation with range N making T queries and using S bits of auxiliary input must satisfy S⋅ T ≥ Nlog N. This lower bound no longer holds in the truncated setting where one must only invert a challenge from a range of size N/2^k, as now one can simply save the replies to all N/2^k challenges, which requires S = log N⋅ N /2^k bits and allows to invert with T = 1 query. We show that with truncation, whenever S is somewhat smaller than the log N⋅ N /2^k bits required to store the entire truncated function table, the known S⋅ T ≥ Nlog N lower bound applies.}, author = {Pietrzak, Krzysztof Z and Wang, Pengxiang}, booktitle = {6th Conference on Information-Theoretic Cryptography}, isbn = {9783959773850}, issn = {1868-8969}, keywords = {Time-Space Lower Bounds, Blockchains}, location = {Santa Barbara, CA, United States}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Time-space tradeoffs of truncation with preprocessing}}, doi = {10.4230/LIPIcs.ITC.2025.4}, volume = {343}, year = {2025}, } @inproceedings{20820, abstract = {The high computational costs of large language models (LLMs) have led to a flurry of research on LLM compression, via methods such as quantization, sparsification, or structured pruning. A new frontier in this area is given by dynamic, non-uniform compression methods, which adjust the compression levels (e.g., sparsity) per-block or even per-layer in order to minimize accuracy loss, while guaranteeing a global compression threshold. Yet, current methods rely on estimating the "importance" of a given layer, implicitly assuming that layers contribute independently to the overall compression error. We begin from the motivating observation that this independence assumption does not generally hold for LLM compression: pruning a model further may even significantly recover performance. To address this, we propose EvoPress, a novel evolutionary framework for dynamic LLM compression. By formulating dynamic compression as a general optimization problem, EvoPress identifies optimal compression profiles in a highly efficient manner, and generalizes across diverse models and compression techniques. Via EvoPress, we achieve state-of-the-art performance for dynamic compression of Llama, Mistral, and Phi models, setting new benchmarks for structural pruning (block/layer dropping), unstructured sparsity, and quantization with dynamic bitwidths.}, author = {Sieberling, Oliver and Kuznedelev, Denis and Kurtic, Eldar and Alistarh, Dan-Adrian}, booktitle = {42nd International Conference on Machine Learning}, issn = {2640-3498}, location = {Vancouver, Canada}, pages = {55556--55590}, publisher = {ML Research Press}, title = {{EvoPress: Accurate dynamic model compression via evolutionary search}}, volume = {267}, year = {2025}, } @inproceedings{20821, abstract = {Modern deep neural networks exhibit heterogeneity across numerous layers of various types such as residuals, multi-head attention, etc., due to varying structures (dimensions, activation functions, etc.), distinct representation characteristics, which impact predictions. We develop a general layer-wise quantization framework with tight variance and code-length bounds, adapting to the heterogeneities over the course of training. We then apply a new layer-wise quantization technique within distributed variational inequalities (VIs), proposing a novel Quantized Optimistic Dual Averaging (QODA) algorithm with adaptive learning rates, which achieves competitive convergence rates for monotone VIs. We empirically show that QODA achieves up to a 150% speedup over the baselines in end-to-end training time for training Wasserstein GAN on 12+GPUs.}, author = {Nguyen, Anh Duc and Markov, Ilia and Wu, Frank Zhengqing and Ramezani-Kebrya, Ali and Antonakopoulos, Kimon and Alistarh, Dan-Adrian and Cevher, Volkan}, booktitle = {42nd International Conference on Machine Learning}, issn = {2640-3498}, location = {Vancouver, Canada}, pages = {46026--46072}, publisher = {ML Research Press}, title = {{Layer-wise quantization for quantized optimistic dual averaging}}, volume = {267}, year = {2025}, }