@article{22307, abstract = {We investigate magnetic active matter in confined geometries using both experiments with magnetic toy robots, Hexbugs, and simulations of elongated magnetic active Brownian particles in circular domains. Standard active particles tend to accumulate at boundaries, forming clusters even at relatively low densities. In the presence of magnetic interactions, we provide evidence for a effect that inhibits clustering and shifts its onset to higher packing fractions. Moreover, magnetic dipolar interactions give rise to collective behaviors such as train-like formations, rotating pairs, and rotating clusters.}, author = {Musacchio, Marco and Felber, Markus and Paoluzzi, Matteo and Gnoli, Andrea and Puglisi, Andrea and Angelani, Luca}, issn = {2470-0053}, journal = {Physical Review E}, number = {5}, publisher = {American Physical Society}, title = {{Fluidization induced by magnetic interactions in confined active matter}}, doi = {10.1103/hylm-ljlf}, volume = {113}, year = {2026}, } @inproceedings{22302, abstract = {Speculative generation has emerged as a promising technique to accelerate inference in large language models (LLMs) by leveraging parallelism to verify multiple draft tokens simultaneously. However, the fundamental limits on the achievable speedup remain poorly understood. In this work, we establish the first “tight” lower bounds on the runtime of any deterministic speculative generation algorithm. This is achieved by drawing a parallel between the token generation process and branching random walks, which allows us to analyze the optimal draft tree selection problem. We prove, under basic assumptions, that the expected number of tokens successfully predicted per speculative iteration is bounded as \mathbb{E}[X] ≤ (𝜇 + 𝜇(2))log(B )/𝜇2 + O(1), where B is the verifier’s batch size, 𝜇 is the expected entropy of the verifier’s output distribution, and 𝜇(2) is this entropy’s second moment. This result provides new insights into the limits of parallel token generation, and could guide the design of future speculative decoding systems. Empirical evaluations on Llama models validate our theoretical predictions, confirming the tightness of our bounds in practical settings.}, author = {Pankratov, Sergei and Alistarh, Dan-Adrian}, booktitle = {Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics}, location = {Rabat, Morocco}, pages = {6404–6418}, publisher = {Association for Computational Linguistics}, title = {{Speculative decoding speed-of-light: Optimal lower bounds via branching random walks}}, doi = {10.18653/v1/2026.eacl-long.301}, year = {2026}, } @unpublished{22276, abstract = {Tissue tension is a key determinant of tissue shape, and its regulation is essential for both morphogenesis and the maintenance of tissue integrity. During zebrafish embryogenesis, the enveloping layer (EVL) – an epithelial monolayer covering the blastoderm – undergoes extensive spreading that is driven by pulling forces exerted at its margin and more than doubles its surface area. Yet whether and how the EVL actively regulates its tissue tension during this process remains unclear. Here, we show that the EVL maintains constant tissue tension while spreading, and that it achieves this by reducing apical cell contractility in response to the same pulling forces that drive its spreading. We identify a mechanosensitive pathway underlying this response, mediated by the scaffold/adaptor protein Kibra regulating the activity of atypical protein kinase C (aPKC) at the apical domain of EVL cells. Under low mechanical stretch, Kibra forms condensates at the base of actin-based apical projections, where it activates Myosin II to increase apical contractility through aPKC downregulation. As mechanical stretch increases, apical projections disassemble, Kibra condensates dissolve, and aPKC activity rises. Elevated aPKC activity in turn reduces apical contractility by reducing Myosin II activity, thereby maintaining constant tissue tension despite increased mechanical stretch. Together, these findings reveal a mechanosensitive mechanism that enables robust adaptation of tissue tension to changing mechanical stretch, ensuring efficient tissue spreading and morphogenesis.}, author = {Hino, Naoya and Kapoor, Tushna and Gubbala, Uday R and Hannezo, Edouard B and Heisenberg, Carl-Philipp J}, keywords = {Epithelial spreading, tissue tension, mechanosensation, aPKC, Kibra, zebrafish}, publisher = {Institute of Science and Technology Austria}, title = {{Apical domain mechanosensation regulates tissue tension homeostasis}}, year = {2026}, } @article{22322, abstract = {We study the problem of continually releasing statistics of an evolving dataset under differential privacy. In the event-level setting, we show the first polynomial lower bounds on the additive error for insertions-only graph problems such as maximum matching, degree histogram and k-core number computation. These results represent an exponential improvement on the polylogarithmic lower bounds of Fichtenberger, Henzinger and Ost [ESA 2021] for the former two problems, and are the first lower bounds in the continual release setting for the latter problem. Our results run counter to the intuition that the difference between insertions-only vs fully dynamic updates causes the gap between polylogarithmic and polynomial additive error. Indeed, we show that for estimating the size of the maximum matching or k-core number of a vertex, allowing small multiplicative approximations is what brings the additive error down to polylogarithmic. We complement these results with improved upper bounds on the additive error when no multiplicative approximation is allowed. Beyond graphs, our techniques also show that polynomial additive error is unavoidable for the Simultaneous Norm Estimation problem in the insertions-only setting. When multiplicative approximations are allowed, we circumvent this lower bound by giving the first continual mechanism with polylogarithmic additive error under (1 + ζ) multiplicative approximations, for any ζ > 0, for estimating all monotone symmetric norms simultaneously. In the item-level setting, we show polynomial lower bounds on the product of the multiplicative and the additive error of continual mechanisms for a large range of graph problems. To the best of our knowledge, these are the first lower bounds shown for any differentially private mechanism under continual release with multiplicative error. To obtain these results, we prove a new lower bound on the product of multiplicative and additive error for the 1-Way-Marginals problem, and give reductions from 1-Way-Marginals to our desired graph problems. This generalizes the prior results of Hardt and Talwar [STOC 2010] and Bun, Ullman and Vadhan [STOC 2014, SIAM J. Comput. 2018], who gave lower bounds on the additive error for the special case of mechanisms with no multiplicative error.}, author = {Aryanfard, Bardiya and Henzinger, Monika H and Saulpic, David and Sricharan, A. R.}, issn = {2836-6573}, journal = {Proceedings of the ACM on Management of Data}, number = {2}, pages = {1--27}, publisher = {Association for Computing Machinery}, title = {{Improved lower bounds for privacy under continual release}}, doi = {10.1145/3801903}, volume = {4}, year = {2026}, } @article{22326, abstract = {In many developmental systems, cells differentiate into a tissue by reading out morphogen concentration fields, a process fundamentally limited by noise. How much can the precision of this process be improved by nonlocal information, e.g., via cell-cell communication? Using a Bayes-optimal framework, we show that positional inference depends crucially on morphogen spatial correlations and on the "structural prior" that encodes the geometry of the cellular lattice performing the readout, thereby determining what a cell can reliably assume about the position of its neighbors when interpreting nonlocal morphogen signals. We derive upper bounds on positional information gain due to nonlocal readout and identify signal processing algorithms that approximate optimal positional inference, as well as simple chemical reaction schemes which implement such algorithms. Our theory suggests that correlational information can be exploited to significantly enhance developmental precision.}, author = {Zhang, Chen Y and Mateu Hoyos, Pablo and Brückner, David and Tkačik, Gašper}, issn = { 1079-7114}, journal = {Physical Review Letters}, publisher = {American Physical Society}, title = {{Nonlocal decoding of positional and correlational information during development}}, doi = {10.1103/mbjk-v4ym}, volume = {137}, year = {2026}, } @article{21777, abstract = {The advantageous characteristics attributed to the 19F nucleus have made it a popular target for nuclear magnetic resonance (NMR) once again in recent years. Aside from solution NMR, an increasing number of studies have been conducted applying solid-state magic-angle spinning (MAS) NMR to fluorine-labelled samples. Here, the high chemical shift anisotropy and strong dipolar couplings can be utilised to get structural insights into proteins and measure long distances. Despite increasing popularity and promising benefits, the sensitivity of biomolecular 19F MAS NMR often suffers from slow longitudinal T1 relaxation and therefore long recycle delays. In this work, we expand paramagnetic doping, an approach commonly used to reduce proton T1 relaxation times, to 19F-labelled biological samples. We study the effect of Gd(DTPA) and Gd(DTPA-BMA) on 19F T1 and T2, and 13C T1 and T2 relaxation in a [5-19F13C]-tryptophan-labelled protein via 19F-detected MAS NMR experiments. The observed paramagnetic relaxation enhancement substantially reduces measurement times of 19F MAS NMR experiments without compromising resolution. Additionally, we report the chemical shift assignments of all four fluorotryptophan signals in the 12×39 kDa-large protein TET2 using a mutagenesis approach.}, author = {Becker, Lea Marie and Toscano, Giorgia and Kapitonova, Anna and Singh, Rajkumar and Guillerm, Undina and Lichtenecker, Roman J. and Schanda, Paul}, issn = {2699-0016}, journal = {Magnetic Resonance}, number = {1}, pages = {29--37}, publisher = {Copernicus Publications}, title = {{Accelerated 19F biomolecular magic-angle spinning NMR with paramagnetic dopants}}, doi = {10.5194/mr-7-29-2026}, volume = {7}, year = {2026}, } @phdthesis{22255, abstract = {This thesis studies spectral rigidity and nonrigidity phenomena in dynamical systems. The central question is whether a dynamical system can be determined, up to a natural conjugacy, from its spectrum. We consider three related spectra: the length spectrum, the action spectrum, and the Lyapunov spectrum. The first part of the thesis concerns Liouville metrics on the two-dimensional torus. It is a long-standing folklore conjecture that Liouville metrics are the only integrable metrics on the torus. We prove a length-spectral rigidity result for linear conformal deformations of Liouville metrics by exploiting the dynamical properties of the rational tori -- analogues of the resonant convex caustics in billiards. We also establish a complementary classification result showing that marked-length-isospectral Liouville metrics are characterized by rearrangements of the one-dimensional functions appearing in their conformal factors, generalizing a theorem of Abbondandolo-Mazzucchelli. In particular, the second result gives nonrigidity examples within the class of Liouville metrics. The second part of the thesis studies the standard map from the viewpoint of action and Lyapunov spectra. We construct nontrivial deformations of the standard map which preserve the symplectic actions (respectively, the Lyapunov exponents) of infinitely many periodic orbits accumulating on an invariant curve. The proof combines a resonant normal form construction with Picard iteration schemes to obtain a sequence of periodic orbits accumulating on an invariant curve with a Liouville rotation number. Within the resonant normal forms we capture the dependence of these periodic orbits on the resonant Fourier coefficients of the dynamics on the invariant curve and, using the contraction mapping principle, obtain a suitable deformation achieving the prescribed spectral data associated with this sequence of orbits. The result can be viewed as a symplectic twist-map analogue of a length-spectral nonrigidity phenomenon for Riemannian manifolds and convex billiards, and it motivates the existence problem for similar 'partially length-isospectral' deformations of strictly convex billiard tables. }, author = {Li, Yunzhe}, issn = {2663-337X}, pages = {131}, publisher = {Institute of Science and Technology Austria}, title = {{Spectral rigidity and nonrigidity of dynamical systems}}, doi = {10.15479/AT-ISTA-22255}, year = {2026}, } @article{22370, abstract = {We report a unified method for the synthesis of α-polyhalomethyl amines from alkenes and alkynes, enabled by readily available hemiaminal reagents. This operationally simple transformation allows for the introduction of not only well-established CF3 and CF2H groups, but also the synthetically (and medicinally) underexplored CF2Cl and CFClH motifs—thereby broadening access to previously inaccessible chemical space of halogenated amine scaffolds. The method displays broad substrate scope and functional-group tolerance while operating under mild conditions. Late-stage functionalization of drug-like derivatives of Oxaprozin, Erlotinib, and Ibuprofen (among others) is reported.}, author = {Hofmeister, Angela K. and Iannelli, Giulia and Angyal, Péter and Malandain, Augustin and Kaiser, Daniel and Maryasin, Boris and Kählig, Hanspeter and Barel, Matteo and Novarino, Gaia and Maulide, Nuno}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, publisher = {Wiley}, title = {{Unified synthesis of unconventional α-polyhalogenated amines through hydroaminoalkylation}}, doi = {10.1002/anie.1233707}, year = {2026}, } @article{22323, abstract = {Arrays of Josephson junctions can be tuned through anomalous metallic, quantum-critical, and insulating regimes. We introduce an alternative experimental probe, capturing microwave radiation across all three regimes, using a two-dimensional array of superconductor-semiconductor hybrid Josephson junctions as a model system. Our approach allows calibration of the sample’s circuit parameters and provides isolation from measurement back-action effects. We measure the radiation temperature of the anomalous metal and find that it is hotter than both the quantum-critical and insulating regimes. We further show that the anomalous metallic regime is more susceptible to additional heating than other regimes, explaining its emergence in otherwise thermalized systems. Turning to the quantum-critical regime, we discover nonlinear scaling of radiative noise with applied bias, consistent with theoretical predictions of universal nonequilibrium behavior at quantum-critical points.}, author = {Galvin, Kristen W and Bubis, Anton and Mikalsen, Melissa and Schiela, William F. and Elfeky, Bassel H. and Strickland, William M. and Phan, Duc T and Shabani, Javad and Higginbotham, Andrew P}, issn = {2331-7019}, journal = {Physical Review Applied}, publisher = {American Physical Society}, title = {{Microwave radiometry of a quantum-critical hybrid Josephson array}}, doi = {10.1103/75bl-mm3b}, volume = {26}, year = {2026}, } @phdthesis{21198, abstract = {In recent years there has been a massive increase in the amount of data generated in a decentralized manner. Ever more powerful edge devices, such as smartphones, have become ubiquitous in most societies on earth. Through text typed, photos taken and apps used, these devices, which we refer to as clients, generate enormous amounts of high quality and complex data. Moreover, the nature of these devices means the data they generate is often sensitive and privacy concerns prevent it being gathered and stored in a central location. This presents a challenge to the modern machine learning paradigm that requires central access to large amounts of data. Federated learning (FL) has emerged as one of the answers to this problem. Rather than bringing the data to the model, FL sends the model to the data. Model training takes place on device, with periodically synchronized updates, allowing data to remain locally stored. While this approach offers significant privacy advantages it comes with its own set of unique challenges. These include: data heterogeneity, the notion that different devices generate data in distinct ways which can negatively impact training dynamics; systems heterogeneity, meaning that different devices may have differing hardware specifications; high communication costs, which are induced by the repeated transferring of models over the network and low device computational power, which limits the use of larger models on device. In this thesis we present a range of methods for federated learning. We focus primarily on the challenge of data heterogeneity, though the methods presented are designed to be well adapted to the other challenges of a federated setting, such as the constraints of limited compute and communication overhead. We first present a method for explicitly modeling client data heterogeneity. The approach formulates clients as samples from a certain probability distribution and infers the parameters of this distribution from the available training clients. This learned distribution then represents the heterogeneity present among the clients and can be sampled from in order to create new simulated clients that are similar to the real clients we have observed so far. Following this we present two methods for directly dealing with data heterogeneity through personalization. Highly heterogeneous client data distributions can mean that learning a single global model becomes suboptimal, and some form of personalization of models to each individual client is required. Our approaches are based around hypernetworks, which we use to generate personalized model parameters without the need for additional training or finetuning. In the first approach we focus on generating full parameterizations of client models using learned embeddings of client data and labels, with a hypernetwork located on the central server. In the second approach we address the more challenging scenario where we want to generate a personalized model for a client without any label information. The hypernetwork is trained to generate a low dimensional representation of a client’s personalized model parameters, allowing it to be transferred to and run on the client devices. In our final presented method, we change our focus and rather than aim to directly address the challenge of data heterogeneity, we instead ensure we are unaffected by it. This is done in the context of k-means clustering and we present a method for federated clustering with a focus on added privacy guarantees.}, author = {Scott, Jonathan A}, issn = {2663-337X}, pages = {158}, publisher = {Institute of Science and Technology Austria}, title = {{Data heterogeneity and personalization in federated learning}}, doi = {10.15479/AT-ISTA-21198}, year = {2026}, } @phdthesis{21021, abstract = {This thesis examines how geometry and topology intersect in the representation, transformation, and analysis of complex shapes. It considers how continuous manifolds relate to their discrete analogues, how topological structures evolve in persistence vineyards, and how tools from topological data analysis can illuminate problems in mathematical physics. Central to this exploration is the question of how structure, both geometric and topological, persists or changes under approximation, sampling, or deformation. The work develops new approaches to skeletal and grid-based representations of surfaces, reveals the full expressive capacity of persistence vineyards, and applies topological methods to the longstanding problem of equilibria in electrostatic fields. These threads braid together into a broader understanding of how topology and geometry inform one another across theory, computation, and application.}, author = {Fillmore, Christopher D}, issn = {2663-337X}, pages = {122}, publisher = {Institute of Science and Technology Austria}, title = {{Braiding geometry and topology to study shapes and data}}, doi = {10.15479/AT-ISTA-21021}, year = {2026}, } @inproceedings{22327, abstract = {Population protocols are a model of distributed computing where 𝑛 agents, each a simple finite-state machine, interact in pairs to solve a common task against a (adversarial) interaction scheduler. This model was intensively studied in recent years; in particular, the problem of relative majority received much attention: Each agent starts with an input opinion (or color) out of 𝑘 possibilities, and the goal is for each agent to eventually output the color with the largest support in the population. Before our work, the state complexity (the minimum number of states required per agent) was only known to be between Ω(𝑘 2 ) and𝑂(𝑘 7 ). Our main contribution is a population protocol that solves the relative majority problem with 𝑘 3 states. We achieve this result with a new protocol called Circles. While prior approaches in the literature relied on duels of agents to find the majority color — an approach that proved effective for the case with two colors — Circles partitions the agents into circular linked lists of decreasing sizes, with the property that no two agents with the same initial color lie in the same circle. We show that Circles always correctly computes the desired structure against the most adversarial of schedulers (weakly fair). We then show that a trivial extension of Circles solves the relative majority problem. We extend our protocol to handle various tie-breaking mechanisms or to support the case where the agents do not share a prior ordering of the colors. Finally, we show that a modification of Circles solves the ranking problem with 2 · 𝑘^4 states, where each agent must output the rank of its initial color in the population.}, author = {Breitkopf, Tom-Lukas and Dallot, Julien and El-Hayek, Antoine and Schmid, Stefan}, booktitle = {Proceedings of the ACM Symposium on Principles of Distributed Computing}, isbn = {9798400725128}, location = {Egham, United Kingdom}, pages = {414 -- 424}, publisher = {Association for Computing Machinery}, title = {{Ranking opinions with few states in population protocols}}, doi = {10.1145/3796701.3815913}, year = {2026}, } @article{14703, abstract = {We present a discretization of the dynamic optimal transport problem for which we can obtain the convergence rate for the value of the transport cost to its continuous value when the temporal and spatial stepsize vanish. This convergence result does not require any regularity assumption on the measures, though experiments suggest that the rate is not sharp. Via an analysis of the duality gap we also obtain the convergence rates for the gradient of the optimal potentials and the velocity field under mild regularity assumptions. To obtain such rates we discretize the dual formulation of the dynamic optimal transport problem and use the mature literature related to the error due to discretizing the Hamilton-Jacobi equation.}, author = {Ishida, Sadashige and Lavenant, Hugo}, issn = {1615-3383}, journal = {Foundations of Computational Mathematics}, keywords = {Optimal transport, Hamilton-Jacobi equation, convex optimization}, pages = {349--384}, publisher = {Springer Nature}, title = {{Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation}}, doi = {10.1007/s10208-024-09686-3}, volume = {26}, year = {2026}, } @article{14278, abstract = {The Birkhoff conjecture says that the boundary of a strictly convex integrable billiard table is necessarily an ellipse. In this article, we consider a stronger notion of integrability, namely, integrability close to the boundary, and prove a local version of this conjecture: a small perturbation of almost every ellipse that preserves integrability near the boundary, is itself an ellipse. We apply this result to study local spectral uniqueness of ellipses using the connection between the wave trace of the Laplacian and the dynamics near the boundary and establish local uniqueness for almost all of them.}, author = {Koval, Illya}, issn = {1432-1297}, journal = {Inventiones Mathematicae}, pages = {221--298}, publisher = {Springer Nature}, title = {{Local strong Birkhoff conjecture and local spectral rigidity of almost every ellipse}}, doi = {10.1007/s00222-025-01397-y}, volume = {244}, year = {2026}, } @phdthesis{22281, abstract = {In this thesis, we took a look at networks, and more specifically, at networks that change over time, whether those are networks in the distributed algorithms sense of the word, or the graph algorithm sense. In distributed algorithms, we looked at two main problems. First, the broadcast problem: given n agents, each agent is tasked to forward a (unique) message to every other agent. Agents collaborate and can copy and forward all messages they have received up until that point. Broadcast is achieved when one agent has successfully broadcast its message to everyone else. We studied the case where the communication network is controlled by an adversary, under the condition that the graph is rooted in every round of communication. We show that the adversary can delay broadcast for at most l (1 + √ 2)n m rounds, improving on the $O(n\log\log n)$ previous upper bound~\cite{fugger2020radius}, and asymptotically matching the $\sim 1.5n$ lower bound~\cite{schwarz2017linear}. We then looked at the stochastic version of the problem: here, the adversary -- parametrized by $k$ where $k=0$ signifies that the adversary has no control, and $k=n$ that the adversary has full control -- can choose parts of the graph, and the graph is then completed stochastically. Here, we are able to look at a stronger version of broadcast: instead of having $n$ messages trying to be broadcast in parallel, we can assume that only one message needs to be broadcasted. We show the bound $\Theta(k+\log n)$. Then, we looked at undecided states dynamics in population protocols: given a population of $n$ agents, where each initially holds an opinion among $k$ different ones. In each round, two agents are chosen uniformly at random, and can interact. If they have different opinions, they forget their opinions and become undecided. If one of them is undecided while the other has an opinion, they undecided agent copies they opinion of the decided one. The question is then, how many interactions does it take for the whole population to share the same opinion? We show a $\Omega(kn\log \frac {\sqrt n} {k \log n})$ lower bound for any $k = o\left(\frac {\sqrt n}{\log n}\right)$. This is tight for any $ k \le n^{\frac 1 2 - \epsilon}$, where $\epsilon >0$ can be any small constant, matching the known $O(kn\log n)$ upper bound for $k = O\left(\frac {\sqrt n} {\log ^2 n}\right)$~\cite{DBLP:conf/podc/AmirABBHKL23}. Finally, in dynamic algorithms, we study the minimum cut problem: we are given a graph, whose vertex set we want to partition into two subsets such that the number of edges crossing from one subset to the other is minimized. Then, the graph can be updated via edge insertions or deletions, and we must update the solution without recomputing everything from scratch. We present an exact fully-dynamic minimum cut algorithm that runs in $n^{o(1)}$ deterministic update time when the minimum cut size is at most $2^{\Theta(\log^{3/4-c}n)}$ for any $c>0$, improving on the previous algorithm~\cite{DBLP:conf/soda/JinST24} whose minimum cut size limit is $(\log n)^{o(1)}$. Using sparsification and randomization techniques, we are able to extend this to all values of the minimum cut in weighted graphs, at the cost of a $(1+o(1))$-approximation ratio.}, author = {El-Hayek, Antoine}, issn = {2663-337X}, pages = {244}, publisher = {Institute of Science and Technology Austria}, title = {{Handling updates and failures: Dynamic graph algorithms and distributed computing on dynamic networks}}, doi = {10.15479/AT-ISTA-22281}, year = {2026}, } @inproceedings{21720, abstract = {We present an exact fully-dynamic minimum cut algorithm that runs in 𝑛𝑜⁡(1) deterministic update time when the minimum cut size is at most 2Θ⁡(log3/4−𝑐⁡𝑛) for any 𝑐 >0, improving on the previous algorithm of Jin, Sun, and Thorup (SODA 2024) whose minimum cut size limit is (log⁡𝑛)𝑜⁡(1). Combined with graph sparsification, we obtain the first (1 +𝜖)-approximate fully-dynamic minimum cut algorithm on weighted graphs, for any 𝜖 ≥2−Θ⁡(log3/4−𝑐⁡𝑛), in 𝑛𝑜⁡(1) randomized update time. Our main technical contribution is a deterministic local minimum cut algorithm, which replaces the randomized LocalKCut procedure from El-Hayek, Henzinger, and Li (SODA 2025).}, author = {El-Hayek, Antoine and Henzinger, Monika H and Li, Jason}, booktitle = {Proceedings of the Annual ACM SIAM Symposium on Discrete Algorithms}, issn = {1557-9468}, location = {Vancouver, Canada}, pages = {613--663}, publisher = {Society for Industrial and Applied Mathematics}, title = {{Deterministic and exact fully-dynamic minimum cut of superpolylogarithmic size in subpolynomial time}}, doi = {10.1137/1.9781611978971.25}, volume = {2026}, year = {2026}, } @article{22403, abstract = {Linear phase‐contrast scanning transmission electron microscopy (STEM) techniques compatible with high‐throughput 4D‐STEM acquisition are widely used to enhance phase contrast in weakly scattering and beam‐sensitive materials. In these modalities, contrast transfer is often suppressed at low spatial frequencies, resulting in a characteristic contrast gap that limits contrast. Approaches that retain low‐frequency phase contrast exist but typically require substantially increased experimental complexity, restricting routine use. Dark‐field STEM imaging captures this missing low‐frequency information through electrons scattered outside the bright‐field disk, but discards a large fraction of the scattered signal and is therefore dose‐inefficient. Fused Full‐field STEM (FF‐STEM) is introduced as a 4D‐STEM imaging modality that overcomes these limitations by combining ptychographic phase reconstruction with tilt‐corrected dark‐field imaging within a single acquisition. Bright‐field data are used to estimate probe aberrations and reconstruct a high‐resolution phase image, while dark‐field data provide complementary low‐frequency contrast. The two channels are fused in Fourier space using Wiener‐band weighting based on the spectral signal‐to‐noise ratio, yielding transfer‐gap‐free images with high contrast. FF‐STEM preserves the upsampling and depth‐sectioning capabilities of ptychography, adds robust low‐frequency contrast characteristic of dark‐field imaging, and enables dose‐efficient, near–real‐time reconstruction.}, author = {You, Shengbo and Varnavides, Georgios and Khavnekar, Sagar and Palatkin, Nikita and Shao, Sihan and Wu, Mingjian and Stroppa, Daniel and Chernikova, Darya and Zhu, Baixu and Egoavil, Ricardo and Vespucci, Stefano and Krishnan, Dileep and Ye, Xingchen and Schur, Florian KM and Spiecker, Erdmann and Pelz, Philipp}, issn = {2198-3844}, journal = {Advanced Science}, publisher = {Wiley}, title = {{Gap‐free information transfer in 4D‐STEM via fusion of complementary scattering channels}}, doi = {10.1002/advs.76620}, year = {2026}, } @article{22406, abstract = {It is known that for a uniform morphic sequence 𝒖 =⟨𝑢𝑛⟩∞ 𝑛=0 and an algebraic number 𝛽 such that |𝛽| >1, the number [[𝒖]]𝛽 :=∑∞ 𝑛=0(𝑢𝑛/𝛽𝑛) either lies in ℚ⁡(𝛽) or is transcendental. In this paper, we show a similar rational–transcendental dichotomy for sequences defined by irreducible Pisot morphisms on binary alphabets. Subject to the Pisot conjecture (an irreducible Pisot morphism has pure discrete spectrum), we generalise the latter result to arbitrary finite alphabets. In certain cases, we are able to show transcendence of [[𝒖]]𝛽 outright. In particular, for 𝑘 ≥2, if 𝒖 is the k-Bonacci word, then [[𝒖]]𝛽 is transcendental.}, author = {Kebis, Pavol and LUCA, FLORIAN and OUAKNINE, JOEL and SCOONES, ANDREW and WORRELL, JAMES}, issn = {1469-4417}, journal = {Ergodic Theory and Dynamical Systems}, keywords = {balanced-pair algorithm, Cobham’s conjecture, k-Bonacci words, Pisot conjecture, subspace theorem}, pages = {1--22}, publisher = {Cambridge University Press}, title = {{Transcendence for Pisot morphic words over an algebraic base}}, doi = {10.1017/etds.2026.10324}, year = {2026}, } @article{20986, abstract = {During complex vocal interactions, different features of acoustic stimuli are integrated to produce appropriate vocal responses,1 such as copying sounds during vocal matching behavior in some animals.2,3,4,5,6,7,8,9,10,11,12 However, little is known about the interplay and possible trade-offs between the different temporal and spectral acoustic features during these vocal exchanges.2,13,14 Nightingales can flexibly match the pitch of their tonal “whistle songs” in real time during counter-singing duels.15,16 Here, we show that the syllable duration of whistle playbacks could alter the song responses of wild nightingales, causing their whistle duration distribution to shift toward the presented stimulus duration. When exposed to whistle playbacks featuring unnatural combinations of pitch and duration, nightingales demonstrate a flexible trade-off between pitch matching and temporal imitation, yet they are constrained by their vocal repertoire. They selectively adapted their vocal responses to approximate these novel stimuli, aligning them with their natural whistle repertoire. We developed a computational model of nightingale whistle-matching behavior that revealed a hierarchical organization of acoustic feature production. During whistle matching, the feature integration process is constrained by the duration of syllables, and pitch matching follows within this temporal framework, forcing a trade-off between the two features. Our findings reveal a complex interplay between the spectral and temporal domains that shapes song-matching behavior.}, author = {Calderon Garcia, Juan Sebastian and Costalunga, Giacomo and Vogels, Tim P and Vallentin, Daniela}, issn = {1879-0445}, journal = {Current Biology}, number = {3}, pages = {791--798.e6}, publisher = {Elsevier}, title = {{Interplay between syllable duration and pitch during whistle matching in wild nightingales}}, doi = {10.1016/j.cub.2025.12.025}, volume = {36}, year = {2026}, } @article{21006, abstract = {Modern experimental methods in programmable self-assembly make it possible to precisely design particle concentrations, shapes and interactions. However, more physical insight is needed before we can take full advantage of this vast design space to assemble nanostructures with complex form and function. Here we show how a substantial part of this design space can be quickly and comprehensively understood by identifying a class of thermodynamic constraints that act on it. These thermodynamic constraints form a high-dimensional convex polyhedron that determines which nanostructures can be assembled at high equilibrium yield and reveals limitations that govern the coexistence of structures. We validate our predictions through detailed, quantitative assembly experiments of nanoscale particles synthesized using DNA origami. Our results uncover physical relationships underpinning many-component programmable self-assembly in equilibrium and form the basis for robust inverse design, applicable to various systems from biological protein complexes to synthetic nanomachines.}, author = {Hübl, Maximilian and Videbæk, Thomas E. and Hayakawa, Daichi and Rogers, W. Benjamin and Goodrich, Carl Peter}, issn = {1745-2481}, journal = {Nature Physics}, pages = {294--301}, publisher = {Springer Nature}, title = {{A polyhedral structure controls programmable self-assembly}}, doi = {10.1038/s41567-025-03120-3}, volume = {22}, year = {2026}, }