@unpublished{21207, abstract = {Personalized federated learning has emerged as a popular approach to training on devices holding statistically heterogeneous data, known as clients. However, most existing approaches require a client to have labeled data for training or finetuning in order to obtain their own personalized model. In this paper we address this by proposing FLowDUP, a novel method that is able to generate a personalized model using only a forward pass with unlabeled data. The generated model parameters reside in a low-dimensional subspace, enabling efficient communication and computation. FLowDUP's learning objective is theoretically motivated by our new transductive multi-task PAC-Bayesian generalization bound, that provides performance guarantees for unlabeled clients. The objective is structured in such a way that it allows both clients with labeled data and clients with only unlabeled data to contribute to the training process. To supplement our theoretical results we carry out a thorough experimental evaluation of FLowDUP, demonstrating strong empirical performance on a range of datasets with differing sorts of statistically heterogeneous clients. Through numerous ablation studies, we test the efficacy of the individual components of the method.}, author = {Zakerinia, Hossein and Scott, Jonathan A and Lampert, Christoph}, booktitle = {arXiv}, title = {{Federated learning with unlabeled clients: Personalization can happen in low dimensions}}, doi = {10.48550/ARXIV.2505.15579}, year = {2025}, } @unpublished{21211, abstract = {We show that, for any graph F and η > 0, there exists a d0 = d0(F, η) such that every nvertex d-regular graph with d ≥ d0 has a collection of vertex-disjoint F-subdivisions covering at least (1 − η)n vertices. This verifies a conjecture of Verstraëte from 2002 and improves a recent result of Letzter, Methuku and Sudakov which additionally required d to be at least polylogarithmic in n. }, author = {Montgomery, Richard and Petrova, Kalina H and Ranganathan, Arjun and Tan, Jane}, booktitle = {arXiv}, title = {{Packing subdivisions into regular graphs}}, doi = {10.48550/arXiv.2508.00480}, year = {2025}, } @article{21235, abstract = {The condensation of charged polymers is an important driver for the formation of biomolecular condensates. Recent experiments suggest that this mechanism also controls the clustering of eukaryotic chromosomes during the late stages of cell division. In this process, interchromosome attraction is driven by the condensation of cytoplasmic RNA and Ki-67, a charged intrinsically disordered protein that coats the chromosomes as a brush. Attraction between chromosomes has been shown to be specifically promoted by a localized charged patch on Ki-67, although the physical mechanism remains unclear. To elucidate this process, we combine coarse-grained simulations and analytical theory to study the RNA-mediated interaction between charged polymer brushes on the chromosome surfaces. We show that the charged patch on Ki-67 leads to interchromosome attraction via RNA bridging between the two brushes, whereby the RNA preferentially interacts with the charged patches, leading to stable, long-range forces. By contrast, if the brush is uniformly charged, bridging is basically absent due to complete adsorption of RNA onto the brush. Moreover, the RNA dynamics becomes caged in presence of the charged patch while remaining diffusive with uniform charge. Our work sheds light on the physical origin of chromosome clustering, while also suggesting a general mechanism for cells to tune work production by biomolecular condensates via different charge distributions.}, author = {Sorichetti, Valerio and Robin, Paul and Palaia, Ivan and Hernandez-Armendariz, Alberto and Cuylen-Haering, Sara and Šarić, Anđela}, issn = {2835-8279}, journal = {PRX Life}, number = {3}, publisher = {American Physical Society}, title = {{Charge distribution of the coating brush drives interchromosome attraction}}, doi = {10.1103/41fd-r847}, volume = {3}, year = {2025}, } @article{21236, abstract = {The migration behavior of colliding cells is critically determined by transient contact interactions. During these interactions, the motility machinery, including the front-rear polarization of the cell, dynamically responds to surface protein-mediated transmission of forces and biochemical signals between cells. While biomolecular details of such contact interactions are increasingly well understood, it remains unclear what biophysical interaction mechanisms govern the cell-level dynamics of colliding cells and how these mechanisms vary across cell types. Here we develop a phenomenological theory based on 14 candidate contact-interaction mechanisms coupling cell position, protrusion, and polarity. Using high-throughput micropattern experiments, we detect which of these phenomenological contact interactions captures the interaction behaviors of cells. We find that various cell types—ranging from mesenchymal to epithelial cells—are accurately captured by a single model with only two interaction mechanisms: polarity-protrusion coupling and polarity-polarity coupling. Remarkably, the qualitatively different interaction behaviors of distinct cells, as well as cells subject to molecular perturbations of surface protein-mediated signaling, can all be quantitatively captured by varying the strength and sign of the polarity-polarity coupling mechanism. Altogether, our data-driven phenomenological theory of cell-cell interactions reveals polarity-polarity coupling as a versatile and general contact-interaction mechanism, which may underlie diverse collective migration behaviors of motile cells.}, author = {Brandstätter, Tom and Brieger, Emily and Brückner, David and Ladurner, Georg and Rädler, Joachim O. and Broedersz, Chase P.}, issn = {2835-8279}, journal = {PRX Life}, number = {3}, publisher = {American Physical Society}, title = {{Data-driven theory reveals protrusion and polarity interactions governing collision behavior of distinct motile cells}}, doi = {10.1103/3hhj-rt1n}, volume = {3}, year = {2025}, } @article{21237, abstract = {Intelligent soft matter lies at the intersection of materials science, physics, and cognitive science, promising to change how we design and interact with materials. This transformative field aims to create materials with life-like capabilities, such as perception, learning, memory, and adaptive behavior. Unlike traditional materials, which typically perform static or predefined functions, intelligent soft matter can dynamically interact with its environment, integrating multiple sensory inputs, retaining past experiences, and making decisions to optimize its responses. Inspired by biological systems, these materials leverage the inherent properties of soft matter such as flexibility, adaptability, and responsiveness to perform functions that mimic cognitive processes. By synthesizing current research trends and projecting their evolution, we present a forward-looking perspective on how intelligent soft matter could be constructed, with the aim of inspiring innovations in areas such as biomedical devices, adaptive robotics, and beyond. We highlight new pathways for integrating sensing, memory and actuation with low-power internal operations, and we discuss key challenges in realizing materials that exhibit truly “intelligent behavior”. These approaches outline a path toward more robust, versatile, and scalable materials that can potentially act, compute, and “think” through their inherent intrinsic material properties—moving beyond traditional smart technologies that rely on external control.}, author = {Baulin, Vladimir A. and Giacometti, Achille and Fedosov, Dmitry A. and Ebbens, Stephen and Varela-Rosales, Nydia R. and Feliu, Neus and Chowdhury, Mithun and Hu, Minghan and Füchslin, Rudolf and Dijkstra, Marjolein and Mussel, Matan and van Roij, René and Xie, Dong and Tzanov, Vassil and Zu, Mengjie and Hidalgo-Caballero, Samuel and Yuan, Ye and Cocconi, Luca and Ghim, Cheol-Min and Cottin-Bizonne, Cécile and Miguel, M. Carmen and Esplandiu, Maria Jose and Simmchen, Juliane and Parak, Wolfgang J. and Werner, Marco and Gompper, Gerhard and Hanczyc, Martin M.}, issn = {1744-6848}, journal = {Soft Matter}, number = {21}, pages = {4129--4145}, publisher = {Royal Society of Chemistry}, title = {{Intelligent soft matter: Towards embodied intelligence}}, doi = {10.1039/d5sm00174a}, year = {2025}, } @article{21241, abstract = {White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks, which are eventually accreted to produce metal pollution. This is a rare class of objects with only eight published systems. In this work, we perform a systematic search for such systems within 500 pc in the Gaia-eDR3 catalog of WDs using the light curves from the Zwicky Transient Facility (ZTF) and present six new candidates. Our selection process targets the top 1% most photometrically variable sources identified using a combined variability metric from ZTF and Gaia eDR3 photometry, boosted by a metric space we define using von Neumann statistics and Pearson-Skew as a novel discovery tool to identify these systems. This is followed by optical spectroscopic observations of visually selected variables to confirm metal pollution. Four of the six systems show long-timescale photometric variability spanning several months to years, resulting either from long-term evolution of transit activity or dust and debris clouds at wide orbits. Among them, WD J1013–0427 shows an indication of reddening during the long-duration dip. Interpreting this as dust extinction makes it the first system to indicate an abundance of dust grains with radius ≲0.3 μm in the occulting material. The same object also shows metal emission lines that map an optically thick eccentric gas disk orbiting within the star’s Roche limit. For each candidate, we infer the abundances of the photospheric metals and estimate accretion rates. We show that transiting debris systems tend to have higher inferred accretion rates compared to the general population of metal-polluted WDs. Growing the number of these systems will further illuminate such comparative properties in the near future. Separately, we also serendipitously discovered an AM Canis Venaticorum showing a very long-duration outburst—only the fourth such system to be known.}, author = {Bhattacharjee, Soumyadeep and Vanderbosch, Zachary P. and Hollands, Mark A. and Tremblay, Pier-Emmanuel and Xu, Siyi and Guidry, Joseph A. and Hermes, J.J. and Caiazzo, Ilaria and Rodriguez, Antonio C. and van Roestel, Jan and El-Badry, Kareem and Drake, Andrew J. and Roulston, Benjamin R. and Riddle, Reed and Rusholme, Ben and Groom, Steven L. and Smith, Roger and Toloza, Odette}, issn = {1538-3873}, journal = {Publications of the Astronomical Society of the Pacific}, number = {7}, publisher = {IOP Publishing}, title = {{A ZTF search for circumstellar debris transits in White Dwarfs: Six new candidates, one with gas disk emission, identified in a novel metric space}}, doi = {10.1088/1538-3873/ade0ea}, volume = {137}, year = {2025}, } @inproceedings{21243, abstract = {Widely deployed consensus protocols in the cloud are often leader-based and optimized for low latency under synchronous network conditions. However, cloud networks can experience disruptions such as network partitions, high-loss links, and configuration errors. These disruptions interfere with the operation of leader-based protocols, as their view change mechanisms interrupt the normal case replication and cause the system to stall. We propose RACS, a novel randomized consensus protocol that ensures robustness against adversarial network conditions. RACS achieves optimal one-round trip latency under synchronous network conditions while remaining resilient to adversarial network conditions. RACS follows a simple design inspired by Raft, the most widely used consensus protocol in the cloud, and therefore enables seamless integration with the existing cloud software stack. Experiments with a prototype running on Amazon EC2 show that RACS achieves 28k cmd/sec throughput, ninefold higher than Raft under adversarial cloud network conditions. Under synchronous network conditions, RACS matches the performance of Multi-Paxos and Raft, achieving a throughput of 200k cmd/sec with a median latency of 300ms, confirming that RACS introduces no unnecessary overhead. Finally, SADL-RACS, a throughput-optimized version of RACS, achieves a throughput of 500k cmd/sec, delivering 150 percent higher throughput than Raft.}, author = {Tennage, Pasindu and Desjardins, Antoine and Kokoris Kogias, Eleftherios}, booktitle = {2025 IEEE 18th International Conference on Cloud Computing}, location = {Helsinki, Finland}, publisher = {IEEE}, title = {{RACS-SADL: Robust and understandable randomized consensus in the cloud}}, doi = {10.1109/cloud67622.2025.00044}, year = {2025}, } @article{21244, abstract = {Given a family of varieties over the projective line, we study the density of fibres that are everywhere locally soluble in the case that components of higher multiplicity are allowed. We use log geometry to formulate a new sparsity criterion for the existence of everywhere locally soluble fibres and formulate new conjectures that generalise previous work of Loughran and Smeets. These conjectures involve geometric invariants of the associated multiplicity orbifolds on the base of the fibration in the spirit of Campana. We give evidence for the conjectures by providing an assortment of bounds using Chebotarev’s theorem and sieve methods, with most of the evidence involving upper bounds. }, author = {Browning, Timothy D and Lyczak, Julian and Smeets, Arne}, issn = {1944-7833}, journal = {Algebra & Number Theory}, number = {10}, pages = {2049--2090}, publisher = {Mathematical Sciences Publishers}, title = {{Paucity of rational points on fibrations with multiple fibres}}, doi = {10.2140/ant.2025.19.2049}, volume = {19}, year = {2025}, } @article{21245, abstract = {Flickering light is a new promising, fully non-invasive brain stimulation technique that utilizes intermittent sensory stimulation to induce brainwave synchronization (entrainment). While the effects of 40 Hz externally induced neural entrainment have been extensively described, little is known about 60 Hz entrainment in humans. This study presents preliminary observations on the neural and somatic response to flickering 60 Hz light in healthy volunteers over a 3-week period. Fourteen volunteers were randomized to receive either 60 Hz flickering white light or constant light as sham (30-min sessions, 3 weeks, 5 days/week on weekdays). Neural entrainment was assessed with EEG on days 1, 5 and 19. Salivary cortisol and C-reactive protein (CRP) levels, measured with ELISA, assessed the somatic response to stimulation. Side effects and well-being were monitored via questionnaires. EEG recordings showed neural entrainment and synchrony in response to 60 Hz flickering light across multiple cortical regions, including occipital, central, temporal, and frontal areas. The entrainment power and synchronization between different cortical regions declined significantly by day 19 compared to day 1, indicating possible neural habituation. Cortisol and CRP salivary levels were unchanged, and minor side effects were reported with equal frequency in the active and sham groups. Our findings show that 60 Hz flickering light can induce significant neural entrainment and synchrony in healthy adults and is well tolerated. The decline in entrainment strength and neural synchrony observed with repeated 60 Hz stimulations suggests plastic changes in the cortex. To the best of our knowledge, this is the first study to characterize neural and somatic responses to repeated 60 Hz flickering visual stimuli. Given the well-known connection between 60 Hz brain oscillations and cognition, neuroplasticity, and their role in neuropsychiatric disorders, additional research in both preclinical and clinical settings is warranted.}, author = {Alamalhoda, MohammadAmin and Leesch, Friederike and Giovanetti, Francesca and Dunne, Eoghan and Pilloni, Giuseppina and Caffrey, Mark and O’Keeffe, Jack and Venturino, Alessandro and Ferretti, Maria Teresa}, issn = {1932-6203}, journal = {PLOS One}, number = {10}, publisher = {Public Library of Science}, title = {{Exploring neural entrainment and synchrony in response to repeated 60 Hz flickering white light in healthy volunteers}}, doi = {10.1371/journal.pone.0332310}, volume = {20}, year = {2025}, } @article{21246, abstract = {Stellar astrophysics relies on diverse observational modalities—primarily photometric light curves and spectroscopic data—from which fundamental stellar properties are inferred. While machine learning (ML) has advanced analysis within individual modalities, the complementary information encoded across modalities remains largely underexploited. We present the dual embedding for stellar astronomy (DESA) model, a novel multimodal foundation model that integrates light curves and spectra to learn a unified, physically meaningful latent space for stars. DESA first trains separate modality-specific encoders using a hybrid supervised/self-supervised scheme, and then aligns them through DualFormer, a transformer-based cross-modal integration module tailored for astrophysical data. DualFormer combines cross- and self-attention, a novel dual-projection alignment loss, and a projection-space eigendecomposition that yields physically structured embeddings. We demonstrate that DESA significantly outperforms leading unimodal and self-supervised baselines across a range of tasks. In zero- and few-shot settings, DESA’s learned representations recover stellar color–magnitude and Hertzsprung–Russell diagrams with high fidelity (R2 = 0.92 for photometric regressions). In full fine-tuning, DESA achieves state-of-the-art accuracy for binary star detection (AUC = 0.99, AP = 1.00) and stellar age prediction (RMSE = 0.94 Gyr). As a compelling case, DESA naturally separates synchronized binaries from young stars—two populations with nearly identical light curves—purely from their embedded positions in UMAP space, without requiring external kinematic or luminosity information. DESA thus offers a powerful new framework for multimodal, data-driven stellar population analysis, enabling both accurate prediction and novel discovery.}, author = {Kamai, Ilay and Bronstein, Alexander and Perets, Hagai B.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, publisher = {IOP Publishing}, title = {{Machine Learning inference of stellar properties using integrated photometric and spectroscopic data}}, doi = {10.3847/1538-4357/ae0cbc}, volume = {994}, year = {2025}, } @article{21247, abstract = {Seasonal snowmelt in High Mountain Asia is an important source of river discharge. Therefore, observation of the spatiotemporal variations in snow cover at catchment scales using high-resolution satellites is essential for understanding changes in water supply from headwater catchments. In this study, we adapt an algorithm to automatically detect the snowline altitude (SLA) using the Google Earth Engine platform with available high-resolution multispectral satellite archives that can be readily applied for areas of interest. Here, we applied and evaluated the tool to five glacierized watersheds across the Himalayas to quantify the changes in seasonal and annual snow cover over the past 21 years and analyze climate reanalysis data to assess the meteorological factors influencing the SLA. Our findings revealed substantial variations in the SLA among sites in terms of seasonal patterns, decadal trends, and meteorological controls. We identify positive trends in SLA in Hidden Valley (+11.9 m yr−1), Langtang (+14.4 m yr−1), and Rolwaling (+8.2 m yr−1) in the Nepalese Himalayas but a negative trend in Satopanth (−15.6 m yr−1) in the western Indian Himalayas and no significant trend in Parlung in southeastern Tibet. We suggest that the increase in SLA in Nepal was caused by warmer temperatures during the monsoon season, whereas the decrease in SLA in India was driven by increased winter snowfall and reduced monsoon snowmelt. By integrating the outcomes of these analyses, we found that long-term changes in SLA are primarily driven by shifts in the local climate, whereas seasonal variability may be influenced by geographic features in conjunction with climate.}, author = {Sasaki, Orie and Miles, Evan S. and Pellicciotti, Francesca and Sakai, Akiko and Fujita, Koji}, issn = {1994-0424}, journal = {The Cryosphere}, number = {11}, pages = {5283--5298}, publisher = {Copernicus Publications}, title = {{Contrasting patterns of change in snowline altitude across five Himalayan catchments}}, doi = {10.5194/tc-19-5283-2025}, volume = {19}, year = {2025}, } @article{21248, abstract = {Camera-type eyes in vertebrates and cephalopods are striking examples of parallel evolution of a complex structure. While comparisons have focused on these two groups, camera-type eyes with likely high functionality are also found in other invertebrate phyla with simpler brains. Employing single-cell RNA sequencing, we identify neurogenic cells in the adult eyes and brain of the marine annelid worm Platynereis dumerilii. Distinct neural stem cells in the camera-type adult eyes, located at the edge of the cup-shaped retina, and adjacent to the glass body/lens, produce radial lines of cells, reminiscent of stem cells in ciliary marginal zones of vertebrate eyes exhibiting life-long growth. Normal proliferation in the eye depends on ambient light, a phenomenon that depends on the integrity of the photoreceptor gene c-opsin1, which is present in emerging rhabdomeric photoreceptors, and impacts on their differentiation. During reproductive maturation, proliferation in the eye as well as the entire brain sharply declines, while cells upregulate molecular characteristics of mammalian adult neural stem cell quiescence. Our data provide insights into the development and modulation of annelid head and brain cells, revealing similarities and differences to vertebrate eye development, neurogenesis and brain plasticity.}, author = {Milivojev, Nadja and Scaramuzza, Federico and Brum, Pedro Ozório and Velastegui Gamboa, Camila L and Andreatta, Gabriele and Raible, Florian and Tessmar-Raible, Kristin}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Light-modulated stem cells in the camera-type eye of an annelid model for adult brain plasticity}}, doi = {10.1038/s41467-025-65631-0}, volume = {16}, year = {2025}, } @inproceedings{21250, abstract = {We investigate the step complexity of the Leader Election problem (and implementing the corresponding test-and-set object) in asynchronous shared memory, where processes communicate through registers supporting atomic read and write and must coordinate so that a single process becomes the leader. Determining tight step complexity bounds for solving this problem is one of the key open problems in the theory of shared memory distributed computing. The best known algorithm is a randomized tournament-tree, which has worst-case expected step complexity O(log N) for N processes. There are provably no deterministic wait-free algorithms, and only restricted lower bounds are known for obstruction-free and randomized wait-free algorithms. We introduce a new lower bound that establishes an Ω((log N)/(log log N + log Q)) step complexity for any obstruction-free Leader Election algorithm, where N is the number of processes, and 2 ≤ Q ≤ N is a bound on the value contention, which we define as the maximum number of different values that processes can be simultaneously poised to write to the same register in any execution of the algorithm. Our result is strictly stronger than previous bounds based on write contention. In particular, it implies new lower bounds on step complexity that depend on register size.}, author = {Alistarh, Dan-Adrian and Ellen, Faith and Fedorov, Alexander}, booktitle = {39th International Symposium on Distributed Computing}, location = {Berlin, Germany}, pages = {3:1--3:16}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{An almost-logarithmic lower bound for leader election with bounded value contention}}, doi = {10.4230/LIPIcs.DISC.2025.3}, volume = {356}, year = {2025}, } @article{21251, abstract = {Cellular membranes differ across the tree of life. In most bacteria and eukaryotes, single-headed lipids self-assemble into flexible bilayer membranes. By contrast, thermophilic archaea tend to possess bilayer lipids together with double-headed, monolayer spanning bolalipids, which are thought to enable cells to survive in harsh environments. Here, using a minimal computational model for bolalipid membranes, we explore the trade-offs at play when forming membranes. We find that flexible bolalipids form membranes that resemble bilayer membranes because they are able to assume a U-shaped conformation. Conversely, rigid bolalipids, which resemble the bolalipids with cyclic groups found in thermophilic archaea, take on a straight conformation and form membranes that are stiff and prone to pore formation when they undergo changes in shape. Strikingly, however, the inclusion of small amounts of bilayer lipids in a bolalipid membrane is enough to achieve fluid bolalipid membranes that are both stable and flexible, resolving this trade-off. Our study suggests a mechanism by which archaea can tune the material properties of their membranes as and when required to enable them to survive in harsh environments and to undergo essential membrane remodelling events like cell division.}, author = {Santana de Freitas Amaral, Miguel and Frey, Felix F and Jiang, Xiuyun and Baum, Buzz and Šarić, Anđela}, issn = {2050-084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Balancing stability and flexibility when reshaping archaeal membranes}}, doi = {10.7554/elife.105432}, volume = {14}, year = {2025}, } @article{21252, abstract = {Context. Recent observational results from asteroseismic studies show that an important fraction of solar-like stars do not present detectable stochastically excited acoustic oscillations. This non-detectability seems to correlate with a high rotation rate in the convective envelope and a high surface magnetic activity. At the same time, the properties of stellar convection are affected by rotation and magnetism. Aims. We investigate the role of rotation in the excitation of acoustic modes in the convective envelope of solar-like stars, to evaluate its impact on the energy injected in the oscillations. Methods. We derived theoretical prescriptions for the excitation of acoustic waves in the convective envelope of rotating solar-like stars. We adopted the rotating mixing-length Theory to model the influence of rotation on convection. We used the MESA stellar evolution code and the GYRE stellar oscillation code to estimate the power injected in the oscillations from our theoretical prescriptions. Results. We demonstrate that the power injected in the acoustic modes is insensitive to rotation if a Gaussian time-correlation function is assumed, while it can decrease by up to 60% for a Lorentzian time-correlation function, for a 20 Ω⊙ rotation rate. We show that the modification of the excitation rate by rotation depends not only on the rotation rate but also on the radial and angular orders of the considered oscillation mode. This result can allow for better constraints on the properties of stellar convection by studying observationally acoustic mode excitation. Conclusions. These results demonstrate how important it is to take into account the modification of stellar convection by rotation when evaluating the amplitude of the stellar oscillations it stochastically excites. They open the path for understanding the large variety of observed acoustic-mode amplitudes at the surface of solar-like stars as a function of surface rotation rates.}, author = {Bessila, L. and Deckx van Ruys, A. and Buriasco, V. and Mathis, S. and Bugnet, Lisa Annabelle and García, R. A. and Mathur, S.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{The impact of rotation on the stochastic excitation of stellar acoustic modes in solar-like pulsators}}, doi = {10.1051/0004-6361/202452093}, volume = {700}, year = {2025}, } @article{21253, abstract = {We solve a problem of Dujmović and Wood (2007) by showing that a complete convex geometric graph on n vertices cannot be decomposed into fewer than n - 1 star-forests, each consisting of noncrossing edges. This bound is clearly tight. We also discuss similar questions for abstract graphs.}, author = {Pach, János and Saghafian, Morteza and Schnider, Patrick}, issn = {0925-7721}, journal = {Computational Geometry}, publisher = {Elsevier}, title = {{Decomposition of geometric graphs into star-forests}}, doi = {10.1016/j.comgeo.2025.102186}, volume = {129}, year = {2025}, } @article{21256, abstract = {Collagen IV is one of the main components of the basement membrane, a layer of material that lines the majority of tissues in multicellular organisms. Collagen IV molecules assemble into networks, providing stiffness and elasticity to tissues and informing cell and organ shape, especially during development. In this work, we develop two coarse-grained models for collagen IV molecules that retain biochemical bond specificity and coarse grain at different length scales. Through molecular-dynamics simulations, we test the assembly and mechanics of the resulting networks and measure their response to strain in terms of stress, microscopic alignment, and bond dynamics. Within the basement membrane, collagen IV networks rearrange by molecule turnover, which affects tissue organization and can be linked with enzyme activity. Here we explore network rearrangements via bond remodeling, the process of breaking and remaking of bonds between network molecules. We then investigate the effects of active (enzymatic) bond remodeling. We find that this nonequilibrium remodeling allows a network to keep its integrity under strain, while relaxing fully over a variety of timescales, a dynamic response that is unavailable to networks undergoing equilibrium remodeling.}, author = {Meadowcroft, Billie and Sorichetti, Valerio and Ratajczyk, Eryk and Perez Verdugo, Fernanda L and Khalilgharibi, Nargess and Mao, Yanlan and Palaia, Ivan and Šarić, Anđela}, issn = {2835-8279}, journal = {PRX Life}, publisher = {American Physical Society}, title = {{Nonequilibrium remodeling of collagen IV networks in Silico}}, doi = {10.1103/gdd5-rnh7}, volume = {3}, year = {2025}, } @inbook{21257, abstract = {We investigate the problem of accurate sparse fine-tuning of large language models (LLMs), that is, fine-tuning pre-trained LLMs on specialized tasks, while inducing sparsity in their weights. Our work is motivated by experiments showing that standard loss-based fine-tuning methods are not able to achieve high accuracy in this setting, especially at high sparsity targets. To address this issue, we perform a detailed study of knowledge distillation losses for fine-tuning of sparse models. We determine an L2-based distillation approach that we term ‘SquareHead’, which enables accurate recovery even at higher sparsities. Investigating the question of efficient inference, we show that sparse LLMs can be executed faster by taking advantage of sparsity. Specifically, we exhibit end-to-end results showing speedups enabled by sparsity, while recovering accuracy, on the following models and tasks, respectively: T5 for language translation, Whisper for speech translation, and open GPT-type models such as the Mosaic Pre-Trained Transformer (MPT) and Llama-2 models for text generation. In particular, for popular generative tasks, we show for the first time that sparse fine-tuning can reach 75% sparsity without drops in accuracy, and provide notable end-to-end speedups for inference on CPUs. Moreover, we also highlight that sparsity is compatible with other compression approaches, such as quantization.}, author = {Kurtic, Eldar and Kuznedelev, Denis and Frantar, Elias and Goinv, Michael and Pandit, Shubhra and Agarwalla, Abhinav and Nguyen, Tuan and Marques, Alexandre and Kurtz, Mark and Alistarh, Dan-Adrian}, booktitle = {Enhancing LLM Performance. Efficacy, Fine-Tuning, and Inference Techniques}, editor = {Passban, Peyman and Way, Andy and Rezagholizadeh, Mehdi}, isbn = {9783031857461}, issn = {2522-803X}, pages = {83--97}, publisher = {Springer Nature}, title = {{Sparse Fine-Tuning for Inference Acceleration of Large Language Models}}, doi = {10.1007/978-3-031-85747-8_6}, year = {2025}, } @article{21260, abstract = {We prove that there does not exist F∈Q[x,y] of degree 4 such that F(Z^2 )=Z ≥0. In particular, this answers a question by John S. Lew and Bjorn Poonen for quartic polynomials.}, author = {Yao Xiao, Stanley and Yamagishi, Shuntaro}, issn = {1435-9863}, journal = {Journal of the European Mathematical Society}, publisher = {EMS Press}, title = {{Quartic polynomials in two variables do not represent all non-negative integers}}, doi = {10.4171/jems/1697}, year = {2025}, } @inproceedings{21262, abstract = {Continuous Group Key Agreement (CGKA) is the primitive underlying secure group messaging. It allows a large group of N users to maintain a shared secret key that is frequently rotated by the group members in order to achieve forward secrecy and post compromise security. The group messaging scheme Messaging Layer Security (MLS) standardized by the IETF makes use of a CGKA called TreeKEM which arranges the N group members in a binary tree. Here, each node is associated with a public-key, each user is assigned one of the leaves, and a user knows the corresponding secret keys from their leaf to the root. To update the key material known to them, a user must just replace keys at log(N) nodes, which requires them to create and upload log(N) ciphertexts. Such updates must be processed sequentially by all users, which for large groups is impractical. To allow for concurrent updates, TreeKEM uses the “propose and commit” paradigm, where multiple users can concurrently propose to update (by just sampling a fresh leaf key), and a single user can then commit to all proposals at once. Unfortunately, this process destroys the binary tree structure as the tree gets pruned and some nodes must be “blanked” at the cost of increasing the in-degree of others, which makes the commit operation, as well as, future commits more costly. In the worst case, the update cost (in terms of uploaded ciphertexts) per user can grow from log(N) to Ω(N). In this work we provide two main contributions. First, we show that MLS’ communication complexity is bad not only in the worst case but also if the proposers and committers are chosen at random: even if there’s just one update proposal for every commit the expected cost is already over √N, and it approaches N as this ratio changes towards more proposals. Our second contribution is a new variant of propose and commit for TreeKEM which for moderate amounts of update proposals per commit provably achieves an update cost of Θ(log(N)) assuming the proposers and committers are chosen at random.}, author = {Auerbach, Benedikt and Cueto Noval, Miguel and Erol, Boran and Pietrzak, Krzysztof Z}, booktitle = {45th Annual International Cryptology Conference}, isbn = {9783032019127}, issn = {1611-3349}, location = {Santa Barbara, CA, United States}, pages = {141--172}, publisher = {Springer Nature}, title = {{Continuous group-key agreement: Concurrent updates without pruning}}, doi = {10.1007/978-3-032-01913-4_5}, volume = {16007}, year = {2025}, }