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2605.07833 2026-05-11 astro-ph.EP astro-ph.IM

A New Global Chemical Equilibrium Code: Refractory Element Signatures in Super-Earths and Sub-Neptunes

Simon Grimm, Marie-Luise Steinmeyer, Aaron Werlen, Caroline Dorn, Hilke Schlichting, Ed Young

AI总结 该研究开发了一种新的全局化学平衡代码,用于模拟超地球和亚海王星等系外行星的大气与熔融内部之间的化学交换过程。通过改进数值求解器,大幅提升了计算效率,使得大规模参数研究成为可能。研究发现,这些行星的大气成分强烈依赖于其内部的难熔元素组成以及水含量,为解释大气观测数据提供了新的约束。

Comments submitted to ApJ, comments welcome

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英文摘要

The atmospheres of super-Earths and sub-Neptunes can be strongly modified by chemical exchange with their molten interiors during long-lived magma ocean phases. Interpreting atmospheric observations requires fast models that self-consistently couple atmospheric chemistry to the composition of the planetary interior. We present an updated implementation of the global chemical equilibrium (GCE) framework from (Schlichting & Young 2022), which computes the equilibrium composition of a coupled metal-silicate-gas system. The numerical solver has been improved using a gradient-based optimizer, reducing the computational cost of solving the chemical network by more than two orders of magnitude and enabling large parameter studies. We apply the framework to a large synthetic population of planets and explore the imprint of bulk refractory composition of Mg, Si, and Fe on atmospheric properties. We consider planets with different masses, thermal states, and volatile inventories. We find that the atmospheric mass fraction and atmospheric metal mass fraction are primarily controlled by the temperature at the atmosphere-magma ocean interface and the planetary water budget, while the accreted hydrogen mass fraction plays a minor role because most hydrogen dissolves into the interior. For planets that accreted water, the refractory ratios Mg/Si and Fe/Si strongly influence carbon partitioning between the gas, silicate, and metal phases, producing large variations in atmospheric atmospheric metal mass fraction and C/O ratios. These results demonstrate that atmospheric compositions of sub-Neptunes depend sensitively on both the volatile inventory and the bulk composition of rocky material, providing new constraints for interpreting atmospheric observations. The new GCE code is open-source.

2605.07832 2026-05-11 math.PR

A Bismut-Elworthy formula for BSDEs with degenerate noise

Davide Addona, Federica Masiero

AI总结 本文在噪声非退化的条件下,推导出适用于退化噪声情形的Bismut-Elworthy公式,该公式用于估计可能在无限维希尔伯特空间中定义的随机微分方程转移半群的梯度。同时,作者还提出了适用于倒向随机微分方程的非线性Bismut公式,扩展了已有研究成果。该研究受到随机波动方程和随机阻尼波动方程应用的启发。

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英文摘要

In this paper we derive a Bismut-Elworthy formula under assumptions weaker than the non degeneracy of the noise. By Bismut-Elworthy formula we mean a gradient type estimate on the transition semigroup of a stochastic differential equation in a possibly infinite dimensional Hilbert space. We also consider a nonlinear version of the Bismut formula for a backward stochastic differential equation, in analogy to what is done in \cite{futeBismut}, where a non-degenerate noise is considered. Our study is motivated by applications to stochastic wave equations and to stochastic damped wave equation.

2605.07829 2026-05-11 stat.ME math.PR

Parametric ROC Analysis and Optimal Cutoff Selection under Scale Mixtures of Skew-Normal Distributions: A Decision-Theoretic Framework with Asymptotic Inference

Renato de Paula, Helena Mouriño, Tiago Dias Domingues

AI总结 本文研究了在二分类问题中,针对连续生物标志物选择最优阈值的问题,提出了一种基于偏斜正态尺度混合分布(SMSN)的参数化ROC分析框架。该方法考虑了疾病流行率和非对称误分类成本的影响,通过最小化加权误分类风险定义最优阈值,并在满足单调似然比条件下证明了其存在性、唯一性和全局最优性。研究表明,该方法在实际应用中可显著降低误分类风险,尤其在非对称决策场景下效果更为明显。

Comments 42 pages, 3 figures

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英文摘要

We study an optimal threshold functional arising in binary classification for continuous biomarkers. While the ROC curve summarizes discriminatory performance across all thresholds, practical threshold selection must also account for disease prevalence and asymmetric misclassification costs. The classical Youden index corresponds to a symmetric special case and may therefore be suboptimal in realistic decision settings. In addition, biomarker distributions in serological and immunological studies often display skewness and heavy tails, making Gaussian ROC models inadequate. We develop a parametric framework for ROC analysis and optimal cutoff selection under the family of scale mixtures of skew-normal (SMSN) distributions, including the skew-normal and skew-t models. The ROC curve and AUC are estimated by plug-in maximum likelihood from separate group fits. The optimal cutoff is defined as the minimiser of a weighted misclassification risk, which yields a likelihood ratio equation extending the Youden criterion. Under a monotone likelihood ratio condition, we establish existence, uniqueness, and global optimality of the cutoff. We further study its local regularity as an implicitly defined functional of the model parameter and derive consistency, asymptotic normality, and a closed-form plug-in variance estimator. A central term in this variance is the local slope of the estimating equation at the optimal threshold, which acts as a local identifiability diagnostic. Monte Carlo experiments across six scenarios show that the asymptotic approximation is accurate and that Wald confidence intervals attain near nominal coverage. An application to SARS-CoV-2 serological data illustrates that the proposed cutoff can differ substantially from the Youden threshold and may reduce estimated misclassification risk by up to 63% under asymmetric decision settings.

2605.07826 2026-05-11 nucl-th hep-ph nucl-ex

Hadronic parity violation: successes, challenges, and future prospects

Susan Gardner, Jonas Karthein, Ulf-G. Meißner, Girish Muralidhara, Petr Navratil, W. Michael Snow

AI总结 本文综述了强子系统中与弱相互作用相关的宇称破坏现象,介绍了其基本特征及当前对相关效应的理解,总结了理论和实验方面的最新进展。文章还展望了未来研究方向,强调通过高精度研究少体核系统,逐步拓展到复杂核体系,为标准模型计算提供新基准,并探索超出标准模型的新物理可能。

Comments 29 pages, 4 figure files, invited chapter for the Encyclopedia of Nuclear Physics

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Hadronic parity violation concerns the study of the interplay of the weak- and strong-interaction dynamics that yields low energy, parity-violating observables in systems of hadrons and nuclei. We explain its essential features, as well as our current understanding of its observed effects, describing recent theoretical and experimental progress in a pedagogical context. We provide a broad overview of ongoing research efforts to show how precision studies of few-nucleon systems can be extended to studies of complex nuclei and, ultimately, to new benchmarks for computations in the Standard Model, as well as to new searches for the dynamics beyond it.

2605.07822 2026-05-11 hep-ph

Pair creation as a source of longitudinal chiral magnetoconductivity

J. L. Acosta Avalo, S. Montesino Castillo, E. E. García Reynaldo

AI总结 本文研究了强磁场下正负电子等离子体中手征输运现象的微观机制,指出通过有限温度量子电动力学中虚光子极化张量的虚部所描述的成对产生过程,可以动态产生纵向手征磁电导率。该机制无需引入外部手征化学势,通过实对产生诱导轴向电荷不守恒,从而在磁场方向产生电流。研究还分析了泡利阻塞对手征不平衡的调控作用,并揭示了高频率下手征活性向非手征活性转变的特征。

Comments 12 pages and 4 figures. arXiv admin note: text overlap with arXiv:2402.16859, arXiv:1602.01402

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We demonstrate that chiral transport in a strongly magnetized electron-positron plasma can arise dynamically from dissipative pair-creation processes encoded in the imaginary part of the photon polarization tensor within one-loop finite-temperature quantum electrodynamics (QED). In the kinematic region corresponding to longitudinal photon absorption, real electron-positron pair production induces axial charge nonconservation and generates an electric current parallel to the magnetic field, without requiring the introduction of an external chiral chemical potential. This provides a microscopic mechanism for chiral magnetic transport, offering an alternative to hydrodynamic or anomaly-based effective descriptions in which chirality imbalance is typically introduced as an external input. We derive an explicit expression for the longitudinal magnetoconductivity associated with this process and show that it exhibits an approximately quadratic dependence on the magnetic field only within a restricted intermediate regime. This behavior emerges from the dominance of the lowest Landau levels as a characteristic of negative longitudinal magnetoresistance. We further analyze how Pauli blocking regulates the pair-creation phase-space and demonstrate that the dynamically generated chiral imbalance is suppressed at high frequencies, revealing a transition between chiral-active and non-chiral-active regimes. Our results connect microscopic QED processes with anomaly-related transport phenomena in strongly magnetized relativistic plasmas, where pair creation provides a dynamical source for chiral imbalance.

2605.07819 2026-05-11 cond-mat.str-el cond-mat.supr-con physics.data-an

Probabilistic denoising for reliable signal extraction in spectroscopy

Younsik Kim, Changyoung Kim

AI总结 该研究提出了一种概率去噪框架,用于在光电子能谱等科学数据中可靠地提取信号并估计逐点预测不确定性。该方法在低计数噪声条件下成功恢复了铜氧化物超导体的能谱特征,并将不确定性传播至后续分析,实现了具有科学意义误差范围的定量参数提取。研究还验证了该方法在二维X射线衍射数据中的广泛适用性,为不确定性感知的深度学习在科学数据分析中的应用提供了严谨的框架。

Comments 8 pages, 5 figures

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While deep learning offers powerful capabilities for scientific research, its application is often hindered by a lack of quantitative reliability. To address this, we introduce a probabilistic denoising framework that simultaneously extracts denoised signals and element-wise predictive uncertainties from noisy data. We demonstrate this approach on three-dimensional angle-resolved photoemission spectroscopy data, showing that the model reliably recovers the spectral features of a cuprate superconductor from Poisson-distributed noise with an average count of only 0.02 electrons per voxel. Crucially, we show that these predicted uncertainties can be propagated into subsequent superconducting gap analyses, enabling quantitative parameter extraction with scientifically meaningful error bars. Furthermore, we validate the broad applicability of our approach by successfully extending it to two-dimensional X-ray diffraction data. Ultimately, this approach establishes uncertainty-aware deep learning not merely as a visualization tool, but as a rigorous framework for scientific data analysis.

2605.07814 2026-05-11 cs.CR cs.SE

Can I Check What I Designed? Mapping Security Design DSLs to Code Analyzers

Sven Peldszus, Frederik Reiche, Kevin Hermann, Sophie Corallo, Thorsten Berger, Robert Heinrich

AI总结 本文研究了安全设计领域特定语言(DSL)与代码级分析工具之间的映射关系,旨在弥合安全设计与实现之间的抽象鸿沟。通过分析66个设计级安全DSL和36个代码分析工具中的559项安全检查,研究提出了SecLan模型,并得到了22位安全专家的验证。研究发现,设计级与实现级安全之间存在较少共性,安全检查常以过于笼统的方式描述,导致DSL与分析工具之间的潜在关系不明显,即使是安全专家也难以全面理解这一复杂性。

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When assessing the potential impact of code-level vulnerabilities, e.g., discovered by automated analyzers, it is essential to consider them in the context of the system's security design. However, this is a challenging task due to the abstraction gap between security design, often specified using security DSLs, and implementation. As we will show, even security experts lack a complete understanding of this relationship. Intrigued by this gap (and the general disconnect between secure design and secure implementation) we present a study of 66 design-level security DSLs and 559 security checks from 36 code-level analyzers. We identify what concepts are common to both and capture them in the SecLan model, which has been validated by 22 security experts. Based on this, we investigate the relationship between DSLs and analyzers quantitatively and explore it qualitatively together with 9 security experts. We learn that there are few commonalities between design-level and implementation-level security; security checks are often described by overly general weaknesses, resulting in many non-obvious potential relationships between security DSLs and analyzers; and even security experts are overwhelmed by this complexity. We provide an empirical basis that helps practitioners and researchers better understand the gap and serves as a first step toward bridging it.

2605.07813 2026-05-11 math.DG

On generalized imaginary $\mathrm{Spin}^c$-Killing spinors

José Luis Carmona Jiménez

AI总结 本文研究了一类广义虚复结构 $\mathrm{Spin}^c$-Killing 线性旋量,其满足特定的共变导数条件。通过引入狄拉克电流向量场,作者在该向量场零点存在的条件下,证明了当流形维数不小于 3 时,流形局部等距于实双曲空间。在狄拉克电流非零的情况下,给出了满足此类旋量的 $\mathrm{Spin}^c$-黎曼流形的全局几何描述,并将一类特定的广义虚复结构 $\mathrm{Spin}^c$-Killing 旋量重新解释为某种具有向量性挠率的联络下的平行旋量。

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A non-trivial spinor field $ψ$ is called a generalized imaginary $\mathrm{Spin}^c$-Killing spinor if $\nabla^{g,A} _X ψ= iμX \cdot ψ$ for all vector fields $X$, where $μ$ is a real function that is not identically zero and $\nabla^{g,A}$ is the $\mathrm{Spin}^c$ Levi-Civita connection with $\mathrm{U}(1)$-connection $A$. Associated with $ψ$ is a vector field $V$, the Dirac current, defined by $g(V,X) = i \langle X\cdot ψ, ψ\rangle$. We prove that if $V$ vanishes somewhere and $\operatorname{dim} M \geq 3$, the manifold is locally isometric to real hyperbolic space. When $V$ never vanishes and $\operatorname{dim} M \geq 3$, we obtain a global geometric description of all $\mathrm{Spin}^c$-Riemannian manifolds carrying such spinors, under the assumption that either the normalized Dirac current $ξ= \frac{V}{|V|}$ is complete or the leaves of $\mathcal{D} = \ker(ξ^\flat)$ are complete. Finally, we reinterpret the case of type~I generalized imaginary $\mathrm{Spin}^c$-Killing spinors in terms of parallel spinors for a suitable connection with vectorial torsion.

2605.07809 2026-05-11 astro-ph.GA

Potamides: Mapping Dark Matter Halo Shapes from Stellar Stream Tracks in the Local Universe

Sirui Wu, Nathaniel Starkman, Sarah Pearson, Jacob Nibauer, Juan Miro-Carretero, David Martinez-Delgado

AI总结 该研究提出了一种名为Potamides的方法,通过分析星系外恒星流的曲率来推断其宿主暗物质晕的形状和取向。研究应用该方法对15个恒星流样本进行分析,发现部分恒星流能够有效限制暗物质晕的扁率和方向,尤其是那些具有边缘包裹环或尖锐转折点的恒星流提供了最强的约束。该成果展示了恒星流形态可用于研究单个外部星系暗物质晕的形状,并为未来大尺度巡天中利用恒星流进行暗物质和重子物理研究提供了重要工具。

Comments Submitted to ApJ

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Stellar streams trace the gravitational potential of their host galaxies and offer a direct probe of dark matter halo geometry. Cosmological simulations predict that halo shapes depend on both baryonic physics and the nature of dark matter, yet observational constraints on halo flattening and orientation remain limited, especially for individual galaxies. We present Potamides, which utilizes the curvature of extragalactic stellar streams to derive constraints on halo shapes. We apply Potamides to 15 stellar streams from the Stellar Stream Legacy Survey to infer the projected axis ratios and orientation of their host halos. We find that some streams in our sample exclude large regions of halo flattenings and halo orientations. Systems with edge-on wrapping loops or sharp turning points yield the strongest constraints, whereas great circle-like streams remain largely uninformative. All streams in our sample support a spherical halo for a given flattening direction. These results demonstrate that stream morphology can provide halo shape constraints for individual external galaxies. With upcoming surveys (such as Euclid, Rubin, Roman, and ARRAKIHS) expected to discover large numbers of stellar streams, this curvature-based technique will enable rapid statistical tests of dark matter and baryonic physics through the shapes and alignments of halos and disks across cosmic time.

2605.07802 2026-05-11 physics.atom-ph

$J=0$ metastable state of $\mathrm{Th}^{2+}$ for a hyperfine-free nuclear clock

S. Sagar Maurya, V. Lal, J. Tiedau, M. V. Okhapkin, E. Peik

AI总结 本文研究了钍离子$\mathrm{Th}^{2+}$中一个$J=0$的亚稳态$6d^2\,{}^3P_0$,该态具有无偶极辐射衰变通道,仅通过电四极跃迁与基态相连,适合用于不受超精细相互作用影响的核钟。研究通过激光激发和荧光探测测量了该态的能级位移和寿命,并利用其同位素位移表征了电子与核电荷分布的相互作用。该态在超高真空环境下可作为几乎不受场致频率漂移影响的高精度核钟候选态。

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We present measurements on a metastable state in $\mathrm{Th}^{2+}$ with the electronic configuration $6d^2\,{}^3P_0\,(5090\ \mathrm{cm^{-1}})$. This is motivated by the prospect of using the state in laser excitation of the low-energy $^{229}$Th nuclear resonance independent from the leading hyperfine interactions. The $6d^2\,{}^3P_0$ state has no dipole-allowed radiative decay channel and is connected to the second ground state $6d^2\,{}^3F_2\,(63\ \mathrm{cm^{-1}})$ through an electric quadrupole transition only. We populate the state by laser excitation at 484~nm via a higher excited level and detect its population in laser-induced fluorescence. The isotope shift of the $J=0$ level between $^{232}\mathrm{Th}^{2+}$ and $^{229}\mathrm{Th}^{2+}$ is determined as a measure of the interaction of electronic and nuclear charge distributions. The lifetime of the level in our ion trap with buffer gas is limited by collisional mixing with the nearby state $5f6d\,{}^3G_3\,(5060\ \mathrm{cm^{-1}})$. In ultrahigh vacuum, it could serve as a hyperfine-free nuclear clock that is largely immune to field-induced frequency shifts via the electron shell.

2605.07801 2026-05-11 eess.SY cs.SY

Sampling-based Model Predictive Control Using Trust Regions

Markus Walker, Marcel Reith-Braun, Daniel Frisch, Uwe D. Hanebeck

AI总结 本文提出了一种基于信任区域的采样型模型预测控制(MPC)方法,通过引入Kullback-Leibler散度约束和可选的熵下界,替代传统方法中依赖启发式调整的超参数策略,从而更有效地优化提议分布。结合确定性局部累积分布采样,进一步提升了采样效率和收敛性能。实验表明,该方法在样本量少和迭代次数有限的情况下表现出更快的收敛速度和更高的效率。

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Sampling-based model predictive control (MPC) algorithms, such as model predictive path integral (MPPI), enable approximate, gradient-free solutions to optimal control problems by drawing samples from a proposal distribution, evaluating their trajectory costs, and updating the proposal parameters accordingly. However, these approaches typically rely on heuristics for adjusting hyperparameters, such as temperature or momentum, or manual tuning. We propose a trust region formulation for sampling-based MPC that constrains updates of the proposal distribution via a principled Kullback--Leibler (KL) divergence bound and, optionally, an entropy lower bound. This replaces heuristic hyperparameter adaptation with values that are optimal w.r.t. the underlying Lagrangian. We further improve sample efficiency and convergence by combining the trust region update with deterministic localized cumulative distribution (LCD)-based sampling. Experiments on two benchmark environments demonstrate that the proposed trust region update achieves faster convergence and better sample efficiency in low-sample and low-iteration regimes, especially when paired with deterministic LCD-based sampling.

2605.07798 2026-05-11 quant-ph physics.atom-ph

Limits of Stable Near-Field Probing in Nanophotonic Traps

Johannes Piotrowski, Constanze Bach, Nicolás Vera Paz, Philipp Schneeweiss, Arno Rauschenbeutel

AI总结 本文研究了在纳米光子陷阱中使用近场进行光学探测的稳定性限制。通过实验发现,由于粒子温度变化引起的位移分布变化,近场耦合强度会随时间波动,导致探测过程具有瞬时性。研究利用光学纳米光纤周围的双色偶极陷阱捕获冷原子,并用导波共振光的倏逝场进行探测,发现探测光会导致原子加热,进而降低耦合强度并引起原子损失,但通过降温可恢复耦合强度。该结果对需要稳定耦合的纳米光子系统具有重要意义。

Comments 6 page main with 4 figures, 3 page supplementary with 6 figures

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Near-fields around nanophotonic structures and waveguides can be used to optically interface particles ranging from atoms and molecules to microscopic biological and synthetic particles. Due to the strong, non-linear dependence of the near-field coupling strength on the particles' position, a change of the spread of the particles' position will change their mean coupling strength. When the particles are trapped, this position spread depends on their temperature, generally leading to temperature-dependent coupling. Here, we experimentally demonstrate that this effect renders optical probing of trapped particles with near fields an inherently transient process. Specifically, we trap cold atoms in a two-color dipole trap surrounding an optical nanofiber and probe them with the evanescent field of guided, resonant light. The scattering of this probe light heats up the atoms, leading to a decrease of the coupling strength as well as loss of atoms. We observe both effects via a concurrent decrease of the absorption signal. In addition, we demonstrate that the coupling strength can be recovered by cooling the atoms back to their initial temperature. Our findings are relevant for numerous situations where stable coupling of trapped particles to a nanophotonic structure is required.

2605.07797 2026-05-11 quant-ph

Quantum jump unravelings for non-Markovian open system dynamics: a review

Federico Settimo, Jyrki Piilo

AI总结 本文综述了用于非马尔可夫开放量子系统动力学的量子跃迁解耦方法,重点介绍了多种广泛使用的跃迁技术,并从数值效率、可分性要求、希尔伯特空间扩展和测量解释等方面进行了讨论。由于实际物理系统中普遍存在超越马尔可夫近似的时序关联,传统的马尔可夫跃迁方法已无法适用,因此需要推广到非马尔可夫情形。本文旨在系统总结现有方法,填补该领域的综述空白。

Comments 31 pages, submitted to "50th anniversary of the GKLS equation" volume in Open Systems and Information Dynamics

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Stochastic unravelings provide a useful way to represent open quantum system dynamics in terms of pure state realizations, and have been widely studied both from a fundamental and from a computational point of view. They were initially formulated for Markovian dynamics described by the Gorini-Kossakowski-Sudarshan-Lindblad master equation. However, due to recent technological and experimental development, most physical relevant dynamics present temporal correlations beyond the Markov approximation. Such correlations cause decay rates to turn temporarily negative, thus requiring the generalization of stochastic unravelings from Markovian to non-Markovian scenarios. Indeed, many unraveling techniques have been introduced in this regime, and a comprehensive review of the different jump methods is currently missing. In this work, we provide an overview of widely used quantum jump unraveling techniques for non-Markovian systems and also discuss them in terms of their numerical efficiency, divisibility requirements, Hilbert space extension, and measurement interpretation.

2605.07795 2026-05-11 math.OC

Scalable Distributed Stochastic Optimization via Bidirectional Compression: Beyond Pessimistic Limits

Grigory Begunov, Alexander Tyurin

AI总结 本文研究了在分布式和联邦学习中,如何通过双向压缩技术实现可扩展的随机优化,突破了此前认为的悲观复杂度限制。作者提出了一种新的压缩方法,即Inkheart SGD和M4,在满足一定结构假设的前提下,实现了比现有方法更优的时间复杂度,使得优化速度能够随工作节点数$n$提升。这一成果为高效分布式优化提供了新的理论支持和算法设计思路。

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In centralized, distributed, and federated learning with stochastic gradients and $n$ workers, it was recently shown that it is infeasible to find an $\varepsilon$-stationary point faster than $\tildeΩ\left(\min\left\{\frac{d κL Δ}{\varepsilon} + \frac{h L Δ}{\varepsilon} + \frac{h σ^2 L Δ}{n \varepsilon^2},\; \frac{h σ^2 L Δ}{\varepsilon^2} + \frac{h L Δ}{\varepsilon}\right\}\right)$ seconds in both homogeneous and heterogeneous settings under standard assumptions: $L$-smoothness, $σ^2$-bounded unbiased stochastic gradients, and lower boundedness of the function, i.e., $f(x) \geq f^*$ for all $x \in \mathbb{R}^d$, where $Δ= f(x^0) - f^*$, $h$ is the computation time, $κ$ is the communication speed between the workers and the server, and $d$ is the dimension of the iterates and gradients. This result is pessimistic since it does not allow a complexity in which both $\frac{d κL Δ}{\varepsilon}$ and $\frac{h σ^2 L Δ}{\varepsilon^2}$ improve with $n$, even when using random sparsification techniques; moreover, this lower bound can be matched by either non-distributed SGD or vanilla Synchronous SGD, which reduces the impact of recent progress in the design of compression-based methods. In this work, we challenge this limitation and propose new compressed methods, Inkheart SGD and M4, and show that under an additional structural assumption, which is necessary due to the lower bound and which does not restrict the class of considered problems, we achieve new state-of-the-art time complexities that break this pessimistic barrier and allow scaling with the number of workers $n$.

2605.07791 2026-05-11 physics.flu-dyn nlin.CD

On the repeatability of turbulence

Noé Clavier, Eberhard Bodenschatz, Florencia Falkinhoff

AI总结 本文研究了湍流的可重复性问题,通过实验手段在Max Planck可变密度湍流风洞中重复生成了多达3万次的衰减湍流,使用主动网格实现初始条件的名义一致性。研究发现,能量承载的湍流大尺度结构表现出显著的可重复性,而小尺度结构则可视为独立随机变量,这一结果支持了当前数值模拟中对小尺度进行参数化处理的方法。

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英文摘要

Turbulence has strong and seemingly random fluctuations. Assessing its repeatability is key to predicting flows in technology and nature, much of which decay as viscosity dissipates energy. Much has been done to this end since the work of Lorenz, but mostly in theory and simulations. Here we present experimental results from the Max Planck Variable Density Turbulence Tunnel where we generated decaying turbulence using an active grid, repeating the process with nominally identical initial conditions up to 30,000 times. In contrast with the case of stationary turbulence we found that the energy-carrying large scales show significant repeatability, irrespective of flow development time and turbulence strength. Small scales, however, can effectively be modeled by independent random variables, supporting current numerical approaches in which they are parametrised.

2605.07789 2026-05-11 cs.HC

Analyzing Human Heuristics and Strategies in Everyday Decision-Making Conversations for Conversational AI Design

Sora Kang, Soyun Jeon, Jinsu Eun, Kwangwon Lee, Chaerin Song, Minyoung Joo, Joonhwan Lee

AI总结 该研究分析了人们在日常决策对话中使用的启发式策略,以指导对话式人工智能的设计。通过分析955段韩国真实对话,研究发现人们更倾向于使用满足而非优化的策略,并依赖内部知识和互动技巧来降低认知负担。研究还揭示了启发式策略在探索和利用阶段的不同作用,并为对话系统与人类决策过程的结合提供了理论依据和设计启示。

Comments CogSci 2026 (Annual Meeting of the Cognitive Science Society 2026)

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英文摘要

Conversational AI increasingly supports everyday decision-making, yet most systems rely on data-centric reasoning rather than the heuristic and interactional strategies people use in natural conversation. To ground design in actual human practice, we analyze 955 real-world Korean conversations (15,476 utterances) involving food and travel decisions, applying a decision-making codebook through an LLM-assisted coding pipeline. Our findings reveal that people prioritize satisficing over optimization, relying heavily on internal knowledge and interactional strategies to manage cognitive load. Critically, we identify a frequency-efficiency mismatch: the most prevalent heuristics sustain conversational flow during exploration, whereas infrequent, rule-based strategies are highly effective at driving resolution during exploitation. By mapping how these patterns transfer across the spectrum of human-AI interaction, this work provides empirical grounding consistent with cognitive theories of decision-making and offers design implications that align AI systems with human heuristic processes.

2605.07788 2026-05-11 cs.SE

Bridging the Programming Language Gap: Constructing a Multilingual Shared Semantic Space through AST Unification and Graph Matching

Junhao Chen, Jingxuan Zhang, Jian He, Yixuan Tang, Weiqin Zou

AI总结 不同编程语言之间的词汇和语法差异给跨语言软件工程任务(如跨语言代码克隆检测和代码检索)带来了挑战。为了解决这一问题,本文提出了一种新方法,通过AST统一和图匹配构建多语言共享语义空间,使功能等效的代码在不同语言间具有相近的表示。实验表明,该方法在跨语言克隆检测和代码检索任务中均显著优于现有方法,取得了较高的精度和召回率提升。

Comments This paper was accepted by EASE 2026

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英文摘要

The lexical and syntactic disparities among different programming languages (e.g., Java and Python) pose significant challenges for multi-language software engineering tasks such as cross-language code clone detection and code retrieval, since queries or code snippets written in one programming language often fail to match equivalent artifacts in another. To bridge this gap between different programming languages, we proposed a novel approach to construct a multi-language shared semantic space, in which functionally equivalent source code written in different programming languages are close to each other. In this approach, we first map the Abstract Syntax Tree (AST) node labels of the code snippets written in different programming languages into a unified label set, thus compressing high-dimensional language-specific tokens into a common embedding space. Then, we employ a Graph Matching Network (GMN) to encode the paired AST graphs into "semantic vectors" that capture functional equivalence between programming languages in a unified code vector space. In such a way, we can eliminate the differences in syntax between different programming languages. To validate the effectiveness of this approach, we apply it to two downstream tasks, including cross-language clone detection and cross-language code retrieval. Experiments demonstrate that our approach substantially outperforms the state-of-the-art baselines in cross-language clone detection, improving Precision from 95.62% to 99.94%, Recall from 97.72% to 99.92%, and F1 score from 96.94% to 99.93%. In terms of cross-language code retrieval, our approach raises the average Mean Reciprocal Rank (MRR) from 0.4909 to 0.5547, showing an absolute gain of 0.0638 (13% relative improvement), which demonstrates its superior ability to rank correct code snippets high across multiple programming languages.

2605.07787 2026-05-11 math.CA math.CV math.FA

Orthogonal Polynomials, a Szegő--Verblunsky Theorem and Baxter's Theorem on the Quaternionic Sphere

Connor J. Gauntlett, David P. Kimsey

AI总结 本文研究了基于四元数单位球上的正交多项式理论,引入了$q$-正测度的概念,并拓展了包括Szegő递推关系、正交多项式零点定理、Szegő–Verblunsky定理以及Baxter定理在内的多个经典结果。研究中利用了Alpay等人提出的Verblunsky系数(或Schur参数)以及矩阵形式下的相关结果,还提出了Schur系数和Verblunsky公式的矩阵值新形式,为四元数上的正交多项式理论提供了新的分析工具。

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英文摘要

We introduce a theory of orthogonal polynomials on the unit sphere of the quaternions based on the notion of a $q$-positive measure (which originated in a work of Alpay, Colombo, the second author and Sabadini). The results we extend to this setting include the Szegő recurrences, the Zeros Theorem for orthogonal polynomials, the Szegő--Verblunsky theorem, and Baxter's theorem; to obtain these results, we utilise the Verblunsky coefficients (or Schur parameters) of Alpay, Colombo and Sabadini and a number of established results in the matricial setting. Our approach also requires matrix-valued analogues of Schur's recurrences for the coefficients of a Schur function and of Verblunsky's formula for the moments of a measure, which appear to be new.

2605.07784 2026-05-11 cs.DS cs.CC cs.SC math.RA

Computing bases in Hermite normal form of lattices of integer relations

George Labahn, Arne Storjohann

AI总结 本文研究如何计算整数关系格的赫米特标准型基底。给定矩阵 $M$ 和 $F$,作者提出了一种随机化算法,用于求解由特定整数关系生成的格的 $n \times n$ 赫米特标准型基底。该算法属于拉斯维加斯类型,具有较高的正确性保证,且在特定情况下与矩阵乘法的复杂度相当,具有较高的效率。

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英文摘要

Given a full column rank $M \in \Z^{\ell \times m}$ and an $F \in \Z^{n \times m}$ we present an algorithm to compute the $n \times n$ basis in Hermite form of the integer lattice comprised of all rows $p \in \Z^{1 \times n}$ such that $pF \in \Z^{1 \times m}$ is in the integer lattice generated by the rows of $M$. The algorithm is randomized of the Las Vegas type, that is, it can fail with probability at most $1/2$, but if fail is not returned it guarantees to produce the correct result. When $M$ is square and $F=I_m$, then the computed basis is the Hermite normal form of $M$, and the algorithm uses about the same number of bit operations as required to multiply together two matrices of the same dimension and size of entries as $M$.

2605.07780 2026-05-11 cond-mat.mtrl-sci

Ferroelectric domains in methylammonium lead iodide perovskite thin-films

Holger Röhm, Tobias Leonhard, Michael J. Hoffmann, Alexander Colsmann

AI总结 本研究通过压电响应力显微镜(PFM)探索了甲基铵铅碘钙钛矿薄膜的铁电特性,发现了具有90纳米宽度的交替极化域,确认其为铁电畴。光导原子力显微镜图像显示了与铁电畴垂直极化分量相关的载流子提取模式,结合原子力和开尔文探针力显微镜结果,证实了这些畴的压电特性,为理解钙钛矿太阳能电池的微观电荷行为提供了新见解。

Comments 6 pages main manuscript + 7 pages Supplementary Information

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Journal ref
Energy Environ. Sci., 2017, 10, 950
英文摘要

We explore the ferroic properties of methylammonium lead iodide perovskite solar cells by Piezoresponse Force Microscopy (PFM). In vertical and horizontal PFM imaging, we find domains of alternating polarization with a width of 90 nm which we identify as polarized ferroelectric domains. High-resolution photo-conductive atomic force micrographs under illumination also show alternating charge carrier extraction patterns which we attribute to the local vertical polarization components within the ferroelectric domains. The correlation of the sample properties with Atomic Force and Kelvin Probe Force Micrographs evidence the piezo-electric nature of the domains.

2605.07779 2026-05-11 quant-ph

Neural network quantum states in the grand canonical ensemble

Anton Hul, Matija Medvidović, Juan Carrasquilla

AI总结 本文提出了一种基于神经网络的量子态架构,用于在 grand canonical 系统中表示对称玻色子波函数,从而能够研究粒子数可变的量子多体系统。通过结合变分蒙特卡洛采样和几何优化方法,该方法在多种一维和二维系统中实现了具有竞争力的变分能量,并能准确收敛到给定化学势下的物理玻色子数。该方法还使得从一阶约化密度矩阵出发计算凝聚分数和径向密度分布等可观测量成为可能,为实际 grand canonical 系统中关键物理量的数值预测提供了新途径。

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英文摘要

Variational Monte Carlo calculations have recently reached state-of-the-art accuracy in the approximation of ground state properties of quantum many-body systems. Making use of flexible neural quantum states and automatic differentiation has bypassed traditional computational obstacles such as reliance on basis sets. In this paper, we propose a neural quantum state architecture capable of representing symmetric bosonic wavefunctions in Fock space, enabling the study of systems with variable particle number. By supplementing our variational state with Monte Carlo sampling and geometric optimization, we demonstrate competitive variational energies across an array of one- and two-dimensional systems, converging to the physical boson number under a set chemical potential. Our approach enables accurate estimates of one-body reduced density matrices, opening access to observables such as condensate fractions and radial density profiles from first principles. Our method opens the door to numerical predictions of key measurable quantities in practical grand canonical systems.

2605.07778 2026-05-11 gr-qc

Scalar memory from compact binary coalescences

Jann Zosso, Silvia Gasparotto, Llibert Aresté Saló, Daniela D. Doneva, Stoytcho S. Yazadjiev

AI总结 本文研究了在标量-高斯-玻那理论框架下,致密双星并合过程中标量记忆效应的产生机制。通过数值相对论模拟,发现并合过程中系统标量电荷的变化会显著增强标量记忆信号,其影响可与纯标量-高斯-玻那理论对张量记忆的修正相比。该结果表明,当额外引力场的渐近电荷在并合过程中发生变化并产生可观测极化时,标量记忆可成为探测新引力物理的重要低频信号标志。

Comments 17 pages, 5 figures

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英文摘要

Gravitational memory provides a distinctive low-frequency probe of gravity, but explicit merger studies beyond general relativity remain limited. In this work, we investigate memory from binary black hole mergers in Ricci-coupled scalar-Gauss-Bonnet gravity, a natural extension of scalar-Gauss-Bonnet theory that admits an additional scalar breathing polarization. Based on numerical-relativity waveforms of binary black hole coalescences, we show that the change in the scalar charge of the system across merger generates a significant scalar-memory contribution. For a GW150914-like system, this effect modifies the memory signal in a gravitational-wave detector on the same observable timescale and by an amount comparable to the pure scalar-Gauss-Bonnet correction to tensor memory. Thus, it can substantially enhance the total deviation from the general-relativity prediction over a broad range of source and detector configurations. We argue that this identifies a general mechanism: whenever a compact-binary merger changes the asymptotic charge of an additional gravitational field, and that field sources an observable extra polarization, the resulting memory can provide a leading low-frequency signature of new gravitational physics.

2605.07777 2026-05-11 astro-ph.HE

Young Massive Star Clusters as TeV Emitters: Constraints from H.E.S.S. and LHAASO

Rowan Batzofin, Pierre Cristofari, Kathrin Egberts

AI总结 本文研究了年轻大质量星团(YMSCs)作为TeV伽马射线源的特性,利用H.E.S.S.和LHAASO的观测数据,通过蒙特卡洛模拟探讨了YMSCs在银河系中加速粒子的能谱、宇宙射线产生效率及风能转化为湍流磁场的比例等关键参数。研究发现有五组参数能够较好地解释观测数据,排除了波姆扩散等部分模型,为理解银河系中YMSCs激波处的粒子加速机制提供了重要约束。

Comments Accepted for publication in A&A 07 May 2026

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英文摘要

Young massive star clusters (YMSCs) have been proposed as excellent candidates for the main sources of Galactic cosmic rays (CRs) up to the PeV range. The detection and study of gamma rays in the very-high-energy (E>100GeV) range has brought arguments in favour of this hypothesis. Current instruments have detected only a few YMSCs. Future observatories are expected to increase this number, providing a larger sample improving our ability to constrain the role of YMSCs in the origin of CRs. We study the population of TeV YMSCs detected and their properties, confronting simulations of the YMSC population to the observed sample, to address the fundamental questions concerning the spectrum of accelerated particles, the efficiency of CR production, and the fraction of the wind luminosity converted into turbulent magnetic fields. Using Monte Carlo methods, we simulate the Galactic population of YMSCs in the gamma-ray domain and confront our simulations to the catalogue of sources of the systematic survey of the Galactic plane performed by H.E.S.S. (HGPS) and the First LHAASO Catalogue of Gamma-Ray Sources. We systematically explore the parameter space of our model, including the slope of accelerated particles $α$, the CR efficiency $η_{\rm CR}$, the fraction of the wind luminosity converted into turbulent magnetic field $η_{\rm b}$, and the diffusion regime. We found 5 possible sets of parameters for which >75% of realisations agree with the combined data from the HGPS and LHAASO 1st catalogue. Certain regions of the parameter space are strongly disfavoured, such as Bohm diffusion. Our model successfully reproduces the YMSC population observed in both catalogues. With future systematic surveys, e.g. the Cherenkov Telescope Array Observatory (CTAO), this approach will help break degeneracies and improve our understanding of particle acceleration at YMSC shocks in the Galaxy.

2605.07774 2026-05-11 cs.DS

Beyond Brooks: $(Δ-1)$-Coloring in Semi-Streaming

Maxime Flin, Magnús M. Halldórsson

AI总结 本文研究了在半流模型下对最大度为Δ且不含Δ团的图进行(Δ-1)-着色的问题。作者设计了一种单遍半流算法,能够在有限空间内完成此类着色。此外,他们还证明了对于任何0 ≤ k < (Δ+1)/2,任何单遍的(Δ−k)-着色算法都需要Ω(n(k+1))的空间,为该问题提供了理论下界。

Comments 34 pages, accepted for publication at ICALP 2026

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英文摘要

Reed [J.~Comb.~Theory B, 1999] showed that graphs of maximum degree $Δ\geq 10^{14}$ without $Δ$-cliques are $(Δ-1)$-colorable. We design a one-pass semi-streaming algorithm for computing such a coloring. Additionally, we prove that any one-pass $(Δ-k)$-coloring algorithm for $0\leq k < (Δ+1)/2$ requires $Ω(n(k+1))$ space.

2605.07773 2026-05-11 physics.soc-ph

Is a team only as strong as its weakest link? Quantifying the short-board effect with AI Agents

Xin Xu, Jiu Zhang, Xiao-Ling Lei, Xiong-Fei Jiang, Long Xiong

AI总结 该研究探讨了团队表现是否受最弱成员限制的问题,即“短板效应”,并借助人工智能代理模拟团队协作过程,验证了这一理论。研究发现,团队绩效不仅受最弱成员影响,当存在多个短板时,其负面影响会叠加,团队整体表现受到所有弱点的综合影响。这一成果深化了对短板理论的理解,并为优化团队管理、组织运作和供应链韧性提供了重要参考。

Comments 15 pages, 4 figures

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英文摘要

The short-board effect, analogous to Liebig's Law of the Minimum, postulates that the collective performance of a team is constrained by its weakest component. This principle has profound implications for the optimization of collaboration in a variety of contexts, including management, education, and organizational structures. Despite its theoretical significance, empirical validation remains elusive due to challenges of assessing individual capabilities, controlling real-world variables, and data biases towards successful outcomes, as well as high employee turnover.To address this absence of knowledge, we employ multi-agents driven by large language models to simulate a teamwork with standard operating procedure, revealing the relationship between individual capability and collective team performance.In homogeneous team configurations, three capability regimes are observed, particularly the Sisyphus predicament state at the critical capability threshold characterized by extensive ineffective efforts and pseudo-high efficiency. Furthermore, with a single weak link quantifying the short-board effect, we highlight different impacts across core and non-core members on the team performance.More importantly, when the team exhibits multiple weak links, a cumulative product effect emerges, demonstrating that team performance is shaped by the aggregated impact of all weaknesses rather than the weakest link solely.This suggests that mitigation strategies should extend beyond the remediation of individual weak links.These findings rigorously elaborate the short-board theory and provide actionable insights to optimize team management, organizational operations, and supply chain resilience.

2605.07770 2026-05-11 cs.IR

FAVOR: Efficient Filter-Agnostic Vector ANNS Based on Selectivity-Aware Exclusion Distances

Junjie Song, Yu Liu, Guoyu Hu, Zhongle Xie, Ming Yang, Beng Chin Ooi, Ke Zhou

AI总结 现代检索系统在处理推荐系统和检索增强生成等应用中的混合查询时,越来越需要将近似最近邻搜索(ANNS)与复杂属性过滤相结合。为了解决现有方法在低选择性场景下难以兼顾搜索效率、过滤通用性和索引连通性的问题,本文提出了一种高效的、与过滤条件无关的向量近似最近邻搜索方法FAVOR。FAVOR通过引入选择性感知的排除距离机制、统一的选择性估计与过滤搜索架构,以及基于选择性的搜索策略选择器,实现了在不同选择性场景下稳定高效的混合查询处理,并在实际数据集上展现出比现有方法更高的查询吞吐量。

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英文摘要

Modern retrieval systems increasingly require integrating approximate nearest neighbor search (ANNS) with complex attribute filtering to handle hybrid queries in applications such as recommendation systems and retrieval-augmented generation (RAG). While HNSW-based inline-filtering methods show promise, existing approaches struggle to deliver high throughput under low-selectivity scenarios while balancing search efficiency, filtering generality, and index connectivity. To address these challenges, we propose FAVOR, an efficient filter-agnostic vector ANNS that supports arbitrary filtering conditions while maintaining stable performance across varying selectivity levels. FAVOR introduces three novel features: (1) an integrated architecture that unifies selectivity estimation and filtered ANNS execution, providing a cohesive solution for hybrid vector-attribute queries; (2) a HNSW-based inline-filtering algorithm that introduces an exclusion distance mechanism to dynamically reshape the vector distance distribution, pushing non-target vectors away from the query while promoting valid candidates toward the query, thus improving search efficiency without compromising generality or graph connectivity; and (3) a selectivity-driven search selector that estimates query selectivity and dynamically routes queries between a pre-filtering brute-force algorithm for low-selectivity cases and an optimized HNSW-based search algorithm for other scenarios, ensuring consistent performance. Extensive experiments on real-world datasets demonstrate that FAVOR achieves a 1.3-5$\times$ higher QPS at $Recall@10 = 95\%$ compared to state-of-the-art methods for arbitrary filtering conditions, while maintaining competitive performance even against tailored solutions in some filtering conditions.

2605.07769 2026-05-11 cs.SE

Coding Agents Don't Know When to Act

Thibaud Gloaguen, Niels Mündler, Mark Müller, Veselin Raychev, Martin Vechev

AI总结 本文研究了代码代理在面对已解决的错误报告时是否能够正确判断是否需要进行代码修改的问题。作者引入了一个名为FixedBench的代码基准,用于评估五个最新模型在无需修改代码的任务中的表现,发现即使是最先进的模型也经常提出不必要的代码更改。研究还揭示了大型语言模型存在“行动偏差”,即倾向于采取行动而非保持不动,表明当前训练目标对人类指导的过度依赖可能影响其决策能力。

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英文摘要

Coding agents are increasingly deployed to autonomously maintain software, including to resolve user-reported issues: a bug report comes in and the agent creates a patch to address it. However, in any real-world deployment, they will encounter stale bug reports about issues that have already been resolved. Agents should recognize this and abstain from modifying the code to avoid accumulating technical debt. To systematically evaluate whether current agents do so, we introduce FixedBench, a code benchmark with 200 human-verified coding tasks in which no code changes are required, testing five recent models across four agent harnesses. We find that even state-of-the-art models fail, proposing undesirable changes (excluding tests and documentation) in $35$ to $65\%$ of cases. Explicit instructions to reproduce the issue before patching partially address this issue but introduce a new failure mode: when an issue is partially fixed, they abstain even though a patch would still be needed. More broadly, our results indicate that LLMs fall prey to an action bias: they choose to act even if inaction would be appropriate. To break this pattern, inaction needs to be explicitly framed as a path to success, which highlights an overreliance on human guidance implicit in current training objectives.

2605.07763 2026-05-11 cs.IT cs.SY eess.SY math.IT

Beam-Aware Radio Map Estimation With Physics-Consistent Parametric Modeling for Unknown Multiple Satellites

Xiucheng Wang, Nan Cheng, Zhisheng Yin, Conghao Zhou, Ruijin Sun

AI总结 本文研究了在未知多颗卫星环境下构建卫星无线电地图(RM)的问题,该问题因卫星集合未知、波束覆盖不可观测以及接收信号强度难以校准而极具挑战性。为此,作者提出了一种基于物理一致参数化建模的波束感知无线电地图估计框架,通过统一卫星识别与信号场重建,有效提升了地图估计的精度与鲁棒性。实验表明,该方法在不同信噪比和卫星数量条件下均表现出更高的空间相关性、更低的均方误差和更优的F1分数,为卫星网络中的干扰感知提供了可靠解决方案。

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英文摘要

Satellite networks with dense low Earth orbit (LEO) constellations rely on aggressive spectrum reuse, making co-channel interference a dominant and rapidly varying factor that limits link availability and complicates spectrum sharing and compliance. Satellite radio map (RM) construction is therefore essential for interference cognition, yet it is challenging because the active satellite set is unknown, beam footprints and pointing are not directly observable, and received signal strength (RSS) measurements are difficult to calibrate under coupled link budget variations and noise. These latent uncertainties yield a severely underdetermined inverse problem with strong signature coherence, where existing methods often trade detection recall for precision and still fail to recover a faithful continuous RSS field. This paper proposes a beam-aware RM estimation framework that unifies active satellite identification and RSS field reconstruction through physics-consistent parametric modeling. An interpretable structural prior links geometry and beam shaping to spatial RSS formation, and an adaptive model order selection strategy infers the number of active satellites from measurements by balancing fit and complexity. Extensive experiments across varying signal to noise ratio (SNR), total satellite count, and active satellite count demonstrate consistently higher RSS spatial correlation, lower root mean squared error (RMSE), and improved F1 score, validating the proposed approach for interference-aware satellite RM construction in satellite networks.

2605.07761 2026-05-11 cs.MA

Emergence of Social Reality of Emotion through a Social Allostasis Model with Dynamic Interpretants

Kentaro Nomura, Yushi Tsubamoto, Takato Horii

AI总结 该研究基于“建构情绪理论”,探讨情绪社会现实如何通过社会代偿机制形成。研究构建了一个计算模型,模拟两个智能体在接收内感受信号、交换推断符号并动态调整自身目标与符号解释的过程中,如何达成共识。实验表明,两个智能体在内感受先验偏好和符号概率分布上趋于一致,验证了基于社会共识的情绪社会现实的涌现过程。

Comments 10 pages, 4 figures

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英文摘要

The theory of constructed emotion defines social reality as the community-level consensus on emotion concepts assigned to interoceptive sensations arising from bodily allostasis and social interaction. In this study, we simulate this emergence process using a computational model that integrates symbol emergence with degrees of freedom in symbol interpretation and active inference. Two agents receive interoceptive signals, exchange inferred symbols, and simultaneously adapt their bodily control goals and symbol interpretations to each other. Experimental results show that the interoceptive prior preferences and symbol probability distributions of the two agents converge, confirming the emergence of social reality grounded in social consensus.

2605.07759 2026-05-11 cond-mat.soft physics.flu-dyn

Elastocapillary morphing of self-encapsulated droplets floating at the oil-air interface

D. Andrini, D. Riccobelli, L. Gazzera, S. Molteni, P. Metrangolo, P. Ciarletta

AI总结 本研究探讨了悬浮在油-空气界面的自封装液滴在蒸发过程中发生的显著形状变化,如扁平化、膜张力局部丧失导致的褶皱和皱缩现象。通过实验、建模与模拟相结合的方法,研究提出了一种轴对称力学框架,综合考虑表面能、膜应变能和重力势能,构建了预测液滴形态演变的模型。该模型能够准确再现实验观测到的形状演化过程,并揭示了由Bond数、表面张力比和密度比等参数决定的形态相图,为理解液滴在蒸发过程中的力学行为提供了理论依据。

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英文摘要

Self-encapsulated droplets floating at an oil--air interface undergo striking shape changes during evaporation, including flattening and localized loss of membrane tension leading to crumpling and wrinkling. Here we combine experiments, modeling and simulations to obtain predictive morphological maps. We perform contact-angle and evaporation experiments on water droplets coated by a hydrophobin protein film and floating in a fluorinated oil, providing reference profiles and volume-loss sequences for quantitative validation. We develop an axisymmetric mechanics framework in which equilibria follow from minimization of a total free energy combining surface energies, membrane strain energy and gravitational potential, subject to volume and contact-line constraints. A quasi-convex tension-relaxation rule accounts for compression-free states and enables coexistence of taut, wrinkled (one principal tension vanishes) and crumpled (both vanish) membrane domains. A finite element algorithm computes quasi-static morphing under volume reduction; key parameters are identified by fitting the reference contact-angle profile and then used without further tuning. The model reproduces the experimentally observed shape evolution and resolves the associated stress redistribution. Systematic parameter scans yield morphological phase diagrams governed by the Bond number, the oil--droplet surface-tension ratio and the density ratio. For buoyant droplets, crumpling relocates between exposed and submerged caps as parameters vary; for heavy droplets, a crossover to circumferential wrinkling along the immersed sidewall emerges. Wall-meniscus variations shift phase boundaries and can suppress bottom crumpling, consistent with wall-affected experiments.