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2512.03063 2026-06-10 cs.SI

Unsupervised Multimodal Graph-based Model for Geo-social Analysis

无监督多模态图模型用于地理社交分析

Ehsaneddin Jalilian, Bernd Resch

AI总结 本文提出无监督多模态图模型,整合语义与地理信息,提升灾难管理和舆论监控中的内容分析效果。

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AI中文摘要

用户生成的社会媒体内容系统分析,特别是结合地理空间上下文,在灾害管理和舆论监控等领域具有重要作用。尽管多模态方法取得显著进展,但现有模型仍碎片化,各自处理模态而非整合为统一端到端模型。为此,我们提出无监督多模态图方法,将语义和地理信息嵌入共享表示空间。该方法包含两种架构:MonoGraph模型联合编码两种模态,MultiGraph模型分别建模语义和地理关系并通过多头注意力机制整合。复合损失结合对比、连贯性和对齐目标,指导学习过程生成语义连贯且空间紧凑的聚类。在四个真实灾难数据集上的实验表明,我们的模型在话题质量、空间连贯性和可解释性上均优于现有基线。该框架固有领域无关,可扩展到多种多模态数据和广泛下游分析任务。

英文摘要

The systematic analysis of user-generated social media content, especially when enriched with geospatial context, plays a vital role in domains such as disaster management and public opinion monitoring. Although multimodal approaches have made significant progress, most existing models remain fragmented, processing each modality separately rather than integrating them into a unified end-to-end model. To address this, we propose an unsupervised, multimodal graph-based methodology that jointly embeds semantic and geographic information into a shared representation space. The proposed methodology comprises two architectural paradigms: a mono graph (MonoGrah) model that jointly encodes both modalities, and a multi graph (MultiGraph) model that separately models semantic and geographic relationships and subsequently integrates them through multi-head attention mechanisms. A composite loss, combining contrastive, coherence, and alignment objectives, guides the learning process to produce semantically coherent and spatially compact clusters. Experiments on four real-world disaster datasets demonstrate that our models consistently outperform existing baselines in topic quality, spatial coherence, and interpretability. Inherently domain-independent, the framework can be readily extended to diverse forms of multimodal data and a wide range of downstream analysis tasks.

2412.19611 2026-06-10 gr-qc hep-th

Newman-Janis Algorithm from Taub-NUT Instantons

从Taub-NUT瞬间子看Newman-Janis算法

Joon-Hwi Kim

AI总结 本文展示Kerr度规是自对偶与反自对偶Taub-NUT瞬间子的非线性叠加,推动Newman-Janis算法成为具有明确物理起源的Kerr度规推导方法。

Comments 7+3 pages, 4 figures

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Journal ref
Phys. Rev. Lett. 136, 231401 (2026)
AI中文摘要

本文展示Kerr度规是自对偶与反自对偶Taub-NUT瞬间子的非线性叠加,推动Newman-Janis算法成为具有明确物理起源的Kerr度规推导方法。

英文摘要

It is shown that the Kerr metric represents the nonlinear superposition of self-dual and anti-self-dual Taub-NUT instantons. This promotes the Newman-Janis algorithm to a rigorous derivation of the Kerr metric with a definite physical origin. In the same way, the Kerr-Newman and charged Kerr-Taub-NUT solutions are systems of Taub-NUT instantons and chiral dyons.

2601.09168 2026-06-10 eess.SP

User-Centric Stream Sensing for Grant-Free Access: Deep Learning with Covariance Differencing

以用户为中心的流感知用于无授权接入:基于协方差差分的深度学习

Sojeong Park, Yeongjun Kim, Hyun Jong Yang

AI总结 本文提出一种基于协方差差分的深度学习框架,用于解决无授权接入中高负载下的流碰撞问题,通过分析信道变化诱导的协方差偏差,建立理论界限,并结合深度学习分类器提升鲁棒性。

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Journal ref
IEEE Wireless Communications Letters, 2026
AI中文摘要

无授权接入对于大规模连接至关重要,但因无协调传输面临碰撞风险。虽然用户侧感知可通过自主传输决策缓解碰撞,但传统方法在超载场景中失效,因为活跃流数超过接收天线数。为解决此问题,我们提出一种差分流感知框架,将问题从估计总流数转变为通过协方差差分隔离新激活流。我们分析信道变化引起的协方差偏差,建立基于信道相关性的理论界限以确定感知窗口大小。为缓解有限采样引起的残余干扰,集成深度学习分类器。在独立和 identically distributed 平坦瑞利衰落和标准化信道环境中进行的模拟表明,所提方法在超载场景中表现优异,优于非深度学习基线方法。

英文摘要

Grant-free (GF) access is essential for massive connectivity but faces collision risks due to uncoordinated transmissions. While user-side sensing can mitigate these collisions by enabling autonomous transmission decisions, conventional methods become ineffective in overloaded scenarios where active streams exceed receive antennas. To address this problem, we propose a differential stream sensing framework that reframes the problem from estimating the total stream count to isolating newly activated streams via covariance differencing. We analyze the covariance deviation induced by channel variations to establish a theoretical bound based on channel correlation for determining the sensing window size. To mitigate residual interference from finite sampling, a deep learning (DL) classifier is integrated. Simulations across both independent and identically distributed flat Rayleigh fading and standardized channel environments demonstrate that the proposed method consistently outperforms non-DL baselines and remains robust in overloaded scenarios.

2601.08021 2026-06-10 cond-mat.stat-mech

Boundary-Induced Drift and Negative Mobility in Constrained Stochastic Systems

边界诱导的漂移与受限随机系统中的负迁移

Meitar Goldfarb, Stanislav Burov

AI总结 研究受限随机动力学中边界几何与各向异性扩散张量的组合如何产生定向运动,并通过一维双粒子系统展示局部边界诱导漂移如何导致宏观传输,包括恒定力下的绝对负迁移。

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Journal ref
Physical Review E 113, 064119 (2026)
AI中文摘要

我们研究了受硬反射边界约束的过阻尼随机动力学,并展示边界几何与各向异性扩散张量的组合通常会生成定向运动。在个体轨迹层面,无净流条件强制在边界处产生斜向反射,从而产生平行于表面的系统漂移。所得到的局部速度具有一般形式 $v_B(\mathbf{x})=\mathbf{t}(\mathbf{x})^{\!\top}\mathbf{D}\,\mathbf{n}(\mathbf{x})$,由扩散张量 $\mathbf{D}$ 和局部边界几何编码在法向 $\mathbf{n}$ 和切向 $\mathbf{t}$ 中决定。尽管这种边界诱导的漂移是局部的,但根据边界接触的统计特性,它可以积累为宏观响应。我们通过一个由两个扩散系数不等的粒子组成的最小一维二元系统,展示了这种局部边界诱导漂移如何导致宏观传输。重复碰撞在配置空间中起反射作用,并导致持续的质心运动,包括在恒定力下的绝对负迁移 regime。

英文摘要

We study overdamped stochastic dynamics confined by hard reflecting boundaries and show that the combination of boundary geometry and an anisotropic diffusion tensor generically generates directed motion. At the level of individual trajectories, the no-flux condition enforces an oblique reflection at the boundary, which produces a systematic drift parallel to the surface. The resulting local velocity takes the general form $v_B(\mathbf{x})=\mathbf{t}(\mathbf{x})^{\!\top}\mathbf{D}\,\mathbf{n}(\mathbf{x})$, determined by the diffusion tensor $\mathbf{D}$ and the local boundary geometry encoded in the normal $\mathbf{n}$ and tangent $\mathbf{t}$. While this boundary-induced drift is local, it can accumulate into a macroscopic response, depending on the statistics of boundary encounters. We illustrate how this local boundary-induced drift gives rise to macroscopic transport using a minimal one-dimensional dimer composed of two particles with unequal diffusion coefficients. The repeated collisions act as reflections in configuration space and lead to sustained center-of-mass motion, including regimes of absolute negative mobility under constant forcing.

2512.23462 2026-06-10 hep-lat hep-ph

Pion scattering in finite volume within the Inverse Amplitude Method

有限体积内基于逆振幅方法的π介子散射

A. Gómez Nicola, R. Molina, Julián A. Sánchez

AI总结 在有限立方体积内,利用手征微扰论和逆振幅方法研究π-π散射,通过离散化所有道并扩展标准恒等式,计算了相互作用能级的体积依赖性,与格点数据吻合。

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AI中文摘要

我们在$L^3$盒子(静止系)内,在手征微扰论(ChPT)和逆振幅方法(IAM)框架下研究有限体积对π-π散射的影响。我们的完整ChPT计算不仅考虑了$s$道环路的离散化,还考虑了$t,u$道和蝌蚪贡献。因此,不仅右手幺正割线,左手连续谱贡献也在有限体积中计算。需要适当扩展标准的Veltman-Pasarino恒等式,以及基于有限立方谐波或正确表示不可约表示的矩阵,在八面体群不可约表示(irreps)张成的内空间上进行适当投影。从ChPT出发,我们在内空间中构建IAM,从而提供有限体积中双π散射相互作用能级的完整体积依赖性。对于各种低能常数集,我们的结果显示在$m_πL \lesssim 2$时与文献中先前分析相比有显著修正,并与能级格点数据兼容。我们期望我们的分析和结果将有助于优化能级和相移的确定过程,提高精度。

英文摘要

We study the effect of a finite volume for pion-pion scattering within Chiral Perturbation Theory (ChPT) and the Inverse Amplitude Method (IAM) in a $L^3$ box (rest frame). Our full ChPT calculation takes into account the discretization not only in the $s$-channel loops but also in the $t,u$- channels and tadpole contributions. Hence, not only the unitarity right-hand cut but also the left-hand one continuum contributions are calculated in the finite volume. A proper extension of the standard Veltman-Pasarino identities is needed, as well as a suitable projection on the internal space spanned by the irreducible representations (irreps) of the octahedral group, based on either a finite set of cubic harmonics or the matrices which represent the irreps properly. From the ChPT we construct the IAM in the internal space, which provides the full volume dependence of the interacting energy levels of two-pions scattering in the finite volume. Our results for various low-energy constants sets show sizable corrections with respect to previous analyses in the literature for $ m_πL \lesssim 2$, being compatible with energy levels lattice data. We expect that our analysis and results will help to optimize the process of determination of energy levels and phase-shifts with higher accuracy.

2601.02579 2026-06-10 astro-ph.GA

COUGS-DESI: A Catalog of Unusual Galaxies with Polar Structures in the DESI Legacy Imaging Surveys

具有极性结构的异常星系目录:基于DESI遗产影像调查

Seneca K. H. Bahr, Aleksandr V. Mosenkov, Jacob A. Guerrette, Isaac H. Jensen, Jonah X. George, Thea E. Spigarelli, Ryan P. Smith, Brandon T. Burton, Kevan W. Beckstead, Jonah D. Seguine, Harrison K. Casper

AI总结 本文通过DESI数据构建了最大的极性结构星系目录,分析了其形态和分布,发现极环占非矮星系的2.2%,为研究极性结构的形成与演化提供了基础。

Comments 22 pages, 15 figures, submitted to A&A

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Journal ref
A&A 710, A145 (2026)
AI中文摘要

极性结构星系(PSGs)包含在光学和动力学上解耦的组件,这些组件以大角度相互取向。这些系统包括极环、极盘、极晕、极核、极尘带和极潮汐结构,尽管稀少,但为研究星系形成与演化提供了有价值见解。本文利用DESI遗产影像调查(DR10)数据,在Siena星系图(SGA)中通过视觉检查、卷积神经网络分类和与先前报告系统的交叉匹配,识别了PSG候选者。每个星系被分配了PSG子类型和宿主形态。分析了PSG的一般性质,并与SGA中所有星系的性质进行了比较。通过简单的图像模拟评估了投影效应。最终的《具有极性结构的异常星系目录》(COUGS-DESI)包含2,989个PSG候选者,包括342个已知对象。投影效应由随机星系重叠引起可忽略不计。样本涵盖了广泛的极性形态,包括1,113个极环、75个极核、216个极晕、185个极尘带和1,315个极潮汐结构。PSG占本地非矮星系的2.2%,其中极环占0.7%。SGA中约1%的S0星系拥有极环,而螺旋星系是我们的目录中PSG宿主中最常见的形态类型。COUGS--DESI将已知PSG候选者的数量增加了十倍,并为详细研究极性结构的形成与演化提供了基础。

英文摘要

Polar-structure galaxies (PSGs) host photometrically and kinematically decoupled components oriented at large angles to one another. These systems, which include polar rings, polar disks, polar halos, polar bulges, polar dust lanes, and polar tidal structures, provide valuable insights into galaxy formation and evolution, although their rarity has limited statistical studies. We aim to construct the largest and most homogeneous catalog of PSGs to date in order to enable robust statistical studies of their properties and occurrence rates in the local Universe. Using DESI Legacy Imaging Surveys (DR10) data, we identified PSG candidates in the Siena Galaxy Atlas (SGA) through visual inspection, convolutional neural network classification, and cross-matching with previously reported systems. Each galaxy was assigned a PSG subtype and host morphology. We analyzed general properties of PSGs and compared them with those for all galaxies in the SGA. Simple image simulations were used to evaluate projection effects. The resulting Catalog of Unusual Galaxies with polar Structures in the DESI Legacy Imaging Surveys (COUGS-DESI) contains 2,989 PSG candidates, including 342 previously known objects. Projection effects from random galaxy overlaps are negligible. The sample spans a wide range of polar morphologies, with 1,113 polar rings, 75 polar bulges, 216 polar halos, 185 polar dust lanes, and 1,315 polar tidal structures. PSGs constitute 2.2% of local non-dwarf galaxies, with polar rings representing 0.7%. Approximately 1% of S0 galaxies in the SGA host polar rings, whereas spirals constitute the most common morphological type among the PSG hosts in our catalog. COUGS--DESI increases the number of known PSG candidates by an order of magnitude and provides a foundation for detailed studies of the formation and evolution of polar structures.

2601.01722 2026-06-10 astro-ph.GA

Dynamical properties and star formation history of a low-mass quenched galaxy at Cosmic Noon

宇宙正午时期一个低质量熄灭星系的动力学性质与恒星形成历史

K. Ito, F. Valentino, W. M. Baker, G. Brammer, R. Gottumukkala, T. Kakimoto, C. D. P. Lagos, M. Onodera, A. Pensabene, G. Scarpe, M. Tanaka, K. E. Whitaker, N. A. Reddy, R. L. Sanders, A. E. Shapley

AI总结 研究通过JWST/NIRSpec光谱确认并分析了一个低质量静止星系,揭示其恒星形成历史和熄灭过程,展示了深空光谱技术对低质量星系的详细研究价值。

Comments 10 pages, 7 figures, 1 table + Appendix. submitted to A&A

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Journal ref
A&A 710, A122 (2026)
AI中文摘要

我们提供了AURORA-LQG1的光谱确认和深入分析,该星系在z_spec=2.0834处,具有log(M_*/M_⊙)=9.6的质量。中分辨率光谱使我们能够测量其恒星速度弥散(σ_⋆=95±33 km s⁻¹),这是在z≈2处光谱确认的静止星系中最小的值。结合其紧凑的大小(0.41±0.03 kpc),它得出动态质量估计为log(M_dyn/M_⊙)=9.75±0.38。其恒星形成历史表明,一半的恒星质量在观测时期约1 Gyr之前已形成,熄灭发生在z=2.08之前约0.2 Gyr。这些结果证实AURORA-LQG1确实被熄灭,而非处于短暂的恒星形成率抑制阶段。AURORA-LQG1符合z≈2处的质量基本平面,此前仅由大质量静止系统所限制。与同一时期通过NIRSpec光栅光谱观测到的更高质量系统相比,AURORA-LQG1的熄灭时间在已观测中是最短的。该星系可能处于一个可能的密集群尺度(约50 kpc)环境中,包含一个有推测光谱红移的伴星和五个候选伴星,并嵌入一个已知的原星团中。其可能的环境影响可能解释了其由外向内熄灭所建议的正梯度大小与波长的关系。本研究证明深JWST/NIRSpec光谱能够对宇宙正午时期低质量静止星系进行详细研究,提供有价值的关于这些未探索低质量系统中熄灭机制的新见解。[摘要]

英文摘要

We present the spectroscopic confirmation and in-depth analysis of AURORA-LQG1, a low-mass quiescent galaxy at $z_{\rm spec}=2.0834$ with $\log(M_\star/M_\odot)=9.6$ observed with medium-resolution JWST/NIRSpec spectroscopy. The deep medium-resolution spectrum enables the measurement of its stellar velocity dispersion ($σ_\star = 95_{-33}^{+38}\,{\rm km\,s^{-1}}$), the smallest value recorded among spectroscopically confirmed quiescent galaxies at $z\sim2$. Coupled with a compact size ($0.41\pm0.03\, {\rm kpc}$), it yields a dynamical mass estimate of $\log(M_{\rm dyn}/M_\odot)=9.75_{-0.38}^{+0.29}$. Its star formation history suggests that half of the stellar mass was in place $\sim1\,{\rm Gyr}$ before the observed epoch, with quenching occurring $\sim0.2\,{\rm Gyr}$ prior to $z=2.08$. These results confirm that AURORA-LQG1 is genuinely quenched, rather than in a temporary phase of suppressed star formation rate. AURORA-LQG1 is consistent with the mass fundamental plane at $z\sim2$, previously constrained only by massive quiescent systems. Compared with more massive counterparts at the same epoch observed with NIRSpec grating spectroscopy, the time since quenching for AURORA-LQG1 is among the shortest observed. The galaxy resides in a possible dense group-scale ($\sim50$ kpc) environment containing one companion with tentative spectroscopic redshift and five companion candidates, and it is embedded in a known protocluster on Mpc scales. A potential environmental influence on its evolution could explain the outside-in quenching suggested by the positive gradient of size with wavelength. This study demonstrates that deep JWST/NIRSpec spectroscopy enables low-mass quiescent galaxies at Cosmic Noon to be characterized with a level of detail long reserved for massive systems, offering valuable new insights into how quenching operates in these underexplored low-mass systems. [Abridged]

2601.00960 2026-06-10 astro-ph.GA

GA-NIFS: AGN activity in a Lyα emitter within a triple-AGN system anchored by a passive galaxy at z=3

GA-NIFS:一个三重AGN系统中被静止星系锚定的Lyα发射体内的AGN活动

Michele Perna, Santiago Arribas, Mahmoud Hamed, Francesco D'Eugenio, J. Andrew Bunker, Stefano Carniani, Stéphane Charlot, Roberto Maiolino, Bruno Rodríguez Del Pino, Hannah Übler, Torsten Böker, Elena Bertola, Giovanni Cresci, Isabella Lamperti, Giacomo Venturi, Michele Ginolfi, Montserrat Villar Martín, Sandra Zamora

AI总结 研究通过新数据确认Lyα发射体LAE2的AGN性质,并分析其物理和电离特性,揭示GS10578周围存在多黑洞活动和气体结构,为理解静止大质量星系的晚期演化提供新见解。

Comments submitted

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Journal ref
A&A 710, A167 (2026)
AI中文摘要

在z>3的高质量淬熄星系挑战早期星系演化模型,因其快速形成和突然淬熄需要高效的反馈,通常与活动星系核(AGN)相关。z=3.1的静止星系GS10578是这一群体的关键例子。先前的JWST/NIRSpec IFU数据揭示了一个AGN喷流,并发现了一个分离约5kpc的紧凑AGN对。此外,VLT/MUSE光谱学发现了第三个AGN候选者,与一个明亮的Lyα发射体(LAE2)相关,该发射体具有高电离的紫外线,但缺乏之前的静止框架光学诊断。我们旨在利用新的JWST数据确认LAE2的性质,并分析LAE2和一个缺乏任何可检测连续体对应物的邻近Lyα发射体(LAE1)的物理和电离特性。我们分析新的NIRSpec IFU观测数据,针对LAE1和LAE2的光学星云线,补充MUSE数据,作为GA-NIFS项目的一部分。我们提取积分和空间解析光谱,构建发射线地图,并使用标准诊断图来确定电离源和运动学。LAE2的线比完全一致于嵌套的AGN。其光学线显示亚千 parsec尺度的斑块状形态和不规则运动学。除了Lyα外,LAE1在所有星云线和JWST成像中均未被检测到。LAE1和LAE2的Lyα轮廓在速度和流量上的相似性表明,LAE1追踪共振散射发射而非原位恒星形成。我们的分析揭示GS10578的环境包含多黑洞活动和十千 parsec尺度的气体结构,为理解反馈和卫星相互作用如何影响静止大质量星系的晚期演化提供新见解。

英文摘要

Massive quenched galaxies at z>3 challenge models of early galaxy evolution, as their rapid formation and abrupt quenching require efficient feedback, often linked to active galactic nuclei (AGN). The quiescent galaxy GS10578 at z=3.1 is a key example of this population. Previous JWST/NIRSpec IFU data revealed an AGN outflow and uncovered a compact pair of AGN separated by ~5 kpc. In addition, VLT/MUSE spectroscopy has identified a third AGN candidate at a projected distance of ~30 kpc, associated with a luminous Lya emitter (LAE2) characterised by high-ionisation UV lines, although rest-frame optical diagnostics were not previously available. We aim to confirm the nature of LAE2 using rest-frame optical diagnostics enabled by new JWST data, and to characterise the physical and ionisation properties of both LAE2 and a distinct nearby Lya emitter (LAE1) that lacks any detectable continuum counterpart. We analyse new NIRSpec IFU observations targeting the optical nebular lines of LAE1 and LAE2, complemented with MUSE data, as part of the GA-NIFS project. We extract integrated and spatially resolved spectra, construct emission-line maps, and use standard diagnostic diagrams to determine ionisation sources and kinematics. LAE2 exhibits line ratios fully consistent with an embedded AGN. Its optical lines display a clumpy morphology and irregular kinematics on sub-kpc scales. Except for Lya, LAE1 remains undetected in all nebular lines and in JWST imaging. The similarity of the LAE1 and LAE2 Lya profiles in both velocity and flux suggests that LAE1 traces resonantly scattered emission rather than in-situ star formation. Our analysis reveals that the environment of GS10578 contains both multi-black-hole activity and gas structures on tens-of-kpc scales, offering new insights into how feedback and satellite interactions influence the late evolutionary stages of quenched massive galaxies.

2512.21836 2026-06-10 cond-mat.mtrl-sci cond-mat.soft

Spectroscopic Characterization of Metallocene Single Crystals Grown by Physical Vapor Transport Method

通过物理气相传输法生长的金属ocene单晶光谱学表征

Ian B. Logue, Sandaruka Jayasooriya Arachchilage, Lance M. Griswold, Moses B. Gaither-Ganim, Lincoln W. Weber, Robyn Cook, Stephen Hofer, Praveena Satkunam, Dipanjan Mazumdar, Poopalasingam Sivakumar, Bumsu Lee

AI总结 通过物理气相传输法制备出高纯度、高均一性的金属ocene单晶,并利用光谱学工具和X射线衍射进行表征,确认其单斜结构及振动特性,为有机光伏、发光显示和分子量子系统提供基础研究。

Comments 15 pages, 5 figures

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Journal ref
Journal of Organometallic Chemistry, 1053, 124138 (2026)
AI中文摘要

通过物理气相传输法制备了具有低杂质密度和高均一性的高质量金属ocene单晶。这些晶体通过多种光谱学工具和X射线衍射进行了表征。激光诱导击穿光谱证实了每个新鲜生长样品中金属离子的存在,尽管所有晶体经历了不同寿命的物理变形。X射线衍射分析确认所有金属ocene单晶在室温下仍保持单斜结构。利用拉曼和傅里叶变换红外光谱研究了金属ocene晶体的振动特性。识别了环间和环内振动模式以及与晶态相关的额外模式作为金属ocene单晶的固有振动特性。鉴于金属ocene在有机光伏、有机发光显示和分子量子系统中的日益重要角色,这项研究将增强我们对更纯净、更结晶化金属ocene单晶固有物理性质的理解。

英文摘要

High-quality metallocene single crystals with a low density of impurities and high homogeneity were prepared using the physical vapor transport method. These crystals were then characterized using various spectroscopic tools and X-ray diffraction. Laser-induced breakdown spectroscopy confirmed the presence of metal ions in each freshly grown sample despite all these crystals undergoing physical deformation with different lifetimes. X-ray diffraction analysis confirmed that all our metallocene single crystals retained a monoclinic structure at room temperature. The vibrational properties of our metallocene crystals were examined using Raman and Fourier-transform infrared spectroscopy. The inter- and intra-ring vibrational modes, along with additional modes associated with the crystalline form, were identified as inherent vibrational properties of our metallocene single crystals. Given the increasingly important role of metallocene in organic solar cells, organic light-emitting displays and molecular quantum systems, this research will enhance our understanding of the intrinsic physical properties of cleaner, more crystalline metallocene single crystals.

2501.12742 2026-06-10 math.CA

L^p-boundedness of the Bochner-Riesz operator

L^p有界性与Bochner-Riesz算子

Zipeng Wang

AI总结 本文提出新的Bochner-Riesz求和方法,证明当0<Reδ<1/2时,Bochner-Riesz算子S^δ在L^p(R^n)上有界,其中(n-1)/(2n)≤1/p≤(n+1)/(2n)

Comments We made certain simplifications and corrected some typos from the previous version

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AI中文摘要

本文给出了Bochner-Riesz求和的新方法。作为结果,我们证明当0<Reδ<1/2时,Bochner-Riesz算子S^δ在L^p(R^n)上有界,其中(n-1)/(2n)≤1/p≤(n+1)/(2n)。

英文摘要

In this paper, we give a new approach to the Bochner-Riesz summability. As a result, we show that the Bochner-Riesz operator $\mathbf{S}^δ, 0<\Reδ<{1\over 2}$ is bounded on $\mathbf{L}^p(\mathbb{R}^n)$ for ${n-1\over 2n}\leq {1\over p}\leq{n+1\over 2n}$.

2503.01276 2026-06-10 math.NA cs.NA

A hierarchical approach for multicontinuum homogenization in high contrast media

多连续体均质化的分层方法

Wei Xie, Viet Ha Hoang, Yin Yang, Yunqing Huang

AI总结 本文提出分层多连续体均质化框架,通过分层宏尺度点和不同分辨率网格解决复杂多尺度系统,实现计算成本降低。

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Journal ref
SIAM Journal on Scientific Computing, 2026, 48(2): A1006-A1027
AI中文摘要

一种 recently developed upscaling technique, the multicontinuum homogenization method, has gained significant attention for its effectiveness in modeling complex multiscale systems. This method defines multiple continua based on distinct physical properties and solves a series of constrained cell problems to capture localized information for each continuum. However, solving all these cell problems on very fine grids at every macroscopic point is computationally expensive, which is a common limitation of most homogenization approaches for non-periodic problems. To address this challenge, we propose a hierarchical multicontinuum homogenization framework. The core idea is to define hierarchical macroscopic points and solve the constrained problems on grids of varying resolutions. We assume that the local solutions can be represented as a combination of a linear interpolation of local solutions from preceding levels and an additional correction term. This combination is substituted into the original constrained problems, and the correction term is resolved using finite element (FE) grids of varying sizes, depending on the level of the macropoint. By normalizing the computational cost of fully resolving the local problem to $\mathcal{O}(1)$, we establish that our approach incurs a cost of $\mathcal{O}(L η^{(1-L)d})$, highlighting substantial computational savings across hierarchical layers $L$, coarsening factor $η$, and spatial dimension $d$. Numerical experiments validate the effectiveness of the proposed method in media with slowly varying properties, underscoring its potential for efficient multiscale modeling.

英文摘要

A recently developed upscaling technique, the multicontinuum homogenization method, has gained significant attention for its effectiveness in modeling complex multiscale systems. This method defines multiple continua based on distinct physical properties and solves a series of constrained cell problems to capture localized information for each continuum. However, solving all these cell problems on very fine grids at every macroscopic point is computationally expensive, which is a common limitation of most homogenization approaches for non-periodic problems. To address this challenge, we propose a hierarchical multicontinuum homogenization framework. The core idea is to define hierarchical macroscopic points and solve the constrained problems on grids of varying resolutions. We assume that the local solutions can be represented as a combination of a linear interpolation of local solutions from preceding levels and an additional correction term. This combination is substituted into the original constrained problems, and the correction term is resolved using finite element (FE) grids of varying sizes, depending on the level of the macropoint. By normalizing the computational cost of fully resolving the local problem to $\mathcal{O}(1)$, we establish that our approach incurs a cost of $\mathcal{O}(L η^{(1-L)d})$, highlighting substantial computational savings across hierarchical layers $L$, coarsening factor $η$, and spatial dimension $d$. Numerical experiments validate the effectiveness of the proposed method in media with slowly varying properties, underscoring its potential for efficient multiscale modeling.

2512.19520 2026-06-10 cond-mat.supr-con cond-mat.str-el

Compressive Strain Turns $s^{\pm}$ into $d$-Wave Pairing in One-unit-cell La$_3$Ni$_2$O$_7$ Thin Film Via Substrate-Induced Hole Doping

压缩应变使$s^{\pm}$转变为$d$波配对,在单单元格La$_3$Ni$_2$O$_7$薄膜中通过衬底诱导空穴掺杂

Yang Zhang, Ling-Fang Lin, Adriana Moreo, Satoshi Okamoto, Thomas A. Maier, Elbio Dagotto

AI总结 研究发现,单单元格La$_3$Ni$_2$O$_7$薄膜中,压缩应变抑制了层间$d_{3z^2-r^2}$跃迁,增强了层内$d_{x^2-y^2}$跃迁的晶场分裂,空穴掺杂显著增强了自旋涨落驱动的配对相关性,导致配对对称性从$d_{x^2-y^2}$转变为$d_{xy}$。

Comments 9 pages, 5 figures

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Journal ref
Phys. Rev. B 113, L140505 (2026)
AI中文摘要

受最近在La$_3$Ni$_2$O$_7$薄膜上生长于LaSrAlO$_4$衬底上常压超导性报告的启发,我们利用从头计算和随机相位近似技术研究了单单元格薄膜中的超导不稳定性和配对对称性变化。与高压体材料相比,单单元格薄膜中层间$d_{3z^2-r^2}$跃迁与层内$d_{x^2-y^2}$跃迁的比值被抑制,层内晶场分裂被增强。我们的计算表明,在常压下,配对相关性由自旋涨落驱动,但随着空穴掺杂显著增强。配对对称性也随着空穴掺杂而改变。具体而言,在中等空穴掺杂下,主导配对对称性为$d_{x^2-y^2}$,在更高掺杂下则为$d_{xy}$。这些状态由内带自旋涨落散射驱动,主要来自远离衬底的Ni层。这些结果强烈表明,薄膜超导样品是空穴掺杂的,配对主要发生在层内,而非高压体材料中的层间配对。

英文摘要

Motivated by recent reports of ambient-pressure superconductivity in La$_3$Ni$_2$O$_7$ films grown on LaSrAlO$_4$, we investigate the superconducting instability in a one-unit cell thin film using {\it ab initio} and random-phase approximation techniques. Compared to the high-pressure bulk system, the ratio of inter-layer $d_{3z^2-r^2}$ hopping to intra-layer $d_{x^2-y^2}$ hopping is suppressed in the 1UC thin film, and the crystal-field splitting of the $e_g$ orbitals is increased. Our calculation indicates that spin-fluctuation-driven pairing correlations are weak for the stoichiometric case at ambient pressure, but increase significantly under hole doping. The leading pairing symmetry is also found to change by hole doping. Specifically, we obtain a leading $d_{x^2-y^2}$ pairing state at moderate hole doping, followed by a $d_{xy}$ state at higher doping. These states are driven by intra-band spin-fluctuation scattering {\it within} the $γ$ hole pocket centered around the M point, and arise primarily from states in the Ni layer {\it farther} from the substrate. These results strongly suggest that the thin-film superconducting samples are hole-doped and that pairing in this system predominantly arises in the layer, as opposed to the inter-layer pairing in the pressurized bulk system.

2512.16517 2026-06-10 astro-ph.CO

How massive neutrinos reshape the cosmic web

重力中微子如何重塑宇宙网

Leonor N. L. Simões, Krishna Naidoo, Benjamin Joachimi, Willem Elbers, Carlos S. Frenk

AI总结 研究通过FLAMINGO模拟探讨重力中微子对宇宙网的影响,发现中微子质量增加会改变密度分布并延迟结构形成,MST图谱能有效区分不同宇宙环境。

Comments 10 pages, 6 figures

详情
Journal ref
Mon Not R Astron Soc (2026)
AI中文摘要

我们通过FLAMINGO模拟探讨了重力中微子对宇宙网的影响。我们将宇宙网分为空洞、片状体、纤维和团块,并发现重力中微子通过减少团块和空洞的体积影响环境。我们发现增加中微子质量会使体积加权密度分布向更高密度偏移,并导致更窄的密度分布,这被解释为中微子延迟结构形成。我们从子晕中构建了最小生成树(MST)图谱,采用数密度以匹配DESI-like观测预期。我们显示大多数MST边位于纤维中,大约70%在不同模拟中。我们还将MST边长信号在不同尺度与不同宇宙网环境联系起来,团块主导小尺度信号,空洞主导长尺度信号,纤维主导中间尺度信号。MST边与宇宙网环境的强相关性强化了MST作为大尺度结构分类器的潜力。我们比较了重子物理和重力中微子的影响,发现它们在MST边长上产生不同的特征。此分析在三维空间中进行,使用子晕的真实位置,而不考虑红移空间扭曲。尽管如此,这些结果强调了MST超越两点统计学的能力,推动了其在真实观测数据中的应用。

英文摘要

We explore the effects of massive neutrinos on the cosmic web using the FLAMINGO simulations. We classify the cosmic web into voids, sheets, filaments, and clusters, and find that massive neutrinos affect the environment by decreasing the volume occupied by clusters and voids. We find that increasing the neutrino mass shifts the volume-weighted density distribution towards higher densities and leads to a more narrow density distribution, which we interpret as neutrinos delaying structure formation. We construct the minimum spanning tree (MST) graph from the subhaloes, adopting a number density chosen to match that expected for DESI-like observations. We show that most MST edges lie in filaments, approximately 70% throughout different simulations, which we link to its sensitivity to neutrino mass. We also link the MST's edge length signal at different scales to different cosmic web environments, with clusters dominating the signal at small scales, voids at longer scales, and filaments at intermediate scales. The strong correlation between MST edges and cosmic web environments reinforces the MST's potential to be used as a classifier for large-scale structure in galaxy surveys. We compare the effects of baryonic physics and massive neutrinos and find that each produces distinct signatures in MST edge lengths. This analysis is performed in 3D space, using the true positions of subhaloes and not accounting for redshift space distortions. Nevertheless, these results emphasise the MST's capability to go beyond two-point statistics, motivating future applications to real observational data.

2512.15604 2026-06-10 astro-ph.CO

Comparing cosmic shear nulling methods for Stage-IV surveys

比较第四阶段巡天中消除宇宙 shear 影响的方法

Naomi Clare Robertson, Alex Hall

AI总结 本文比较了三种消除宇宙 shear 测量中 baryon 反馈影响的方法,评估了它们在减少宇宙学约束偏倚方面的有效性,发现这些方法对 S8 和暗能量参数有显著影响。

Comments Published in the Open Journal of Astrophysics

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AI中文摘要

我们提出了一个分析,比较了减少 baryon 反馈对宇宙 shear 测量影响的 nulling 策略。我们考虑了三种不同的方法,旨在通过应用于数据向量的变换来“消除”高 k 模式:Bernardeau-Nishimichi-Taruya(BNT)变换,作用于透镜场;一种新的 LU 分解离散化 Limber 积分(LUnul)的实现,作用于透镜两点统计;以及最后一种利用相关 LSS 标记物来抑制低红移贡献(交叉相关)的方法。我们比较了这些方法与未消除(或标准)宇宙 shear,在数据向量层面评估这些方法是否能通过 Fisher 预测减少宇宙学约束的偏倚。我们发现所考虑的 nulling 技术对 S8 和暗能量参数的偏倚减少有显著影响。交叉相关方法在减少 S8 偏倚方面有效,但需要额外的来自星系聚类的信息。LUnul 方法是最激进的,因此随着 k_max 的增加,它减少了偏倚最有效,尽管这种准确性提高是以精度为代价的。BNT 方法比 LUnul 保留更多信息,并具有更严谨的理论基础。我们证明了这三种方法都能有效减轻偏倚,并可以应用于未来的透镜分析。

英文摘要

We present an analysis comparing nulling strategies for reducing the impact of baryon feedback on cosmic shear measurements. We consider three different approaches which aim to `null' the high-$k$ modes using transformations applied to the data vector: the Bernardeau-Nishimichi-Taruya (BNT) transform which operates on the lensing field, a new implementation of an LU factorisation of the discretized Limber integral (LUnul) which operates on the lensing two-point statistics, and finally a method which uses a correlated LSS tracers to suppress contributions from lower redshifts (cross-correlation). We compare these methods to un-nulled (or standard) cosmic shear at the data vector level and assess whether these methods are able to reduce the bias on cosmological constraints using a Fisher forecast. We find that the nulling techniques considered can have a large impact on reducing the bias on $S_8$ and Dark Energy parameters. The cross-correlation method is effective at reducing biases in $S_8$, but requires additional information from galaxy clustering. The LUnul method is the most aggressive of the methods and hence reduces biases most efficiently as $k_{\rm max}$ is increased, although this improvement in accuracy comes at the cost of precision. The BNT approach preserves more information than LUnul, and has a more rigorous theoretical grounding. We demonstrate that all three of these methods are effective at mitigating bias, and can be readily applied in forthcoming lensing analyses.

2512.14920 2026-06-10 gr-qc

Gravitational decoupling and regular hairy black holes: Geodesic stability, quasinormal modes, and thermodynamic properties

引力解耦与规则毛黑洞:测地线稳定性、 quasinormal 模式及热力学性质

R. C. de Paiva, K. S. Alves, R. T. Cavalcanti, R. da Rocha

AI总结 研究规则毛黑洞在引力解耦设定下的测地线稳定性,探讨毛参数对轨道稳定性的影响,并分析其 quasinormal 模式及热力学性质。

Comments 39 pages, 15 figures

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Journal ref
Annals Phys. 492 (2026) 170540
AI中文摘要

通过Lyapunov指数研究规则毛黑洞周围测地线轨道的稳定性,量化动态系统中邻近轨迹发散率。探讨了时样测地线和光样测地线,分析毛参数对轨道稳定性的影响。偏离Schwarzschild解对轨道稳定性有显著影响,可能提供观测特征。计算了规则毛黑洞的quasinormal模式,并讨论其热力学性质。报告了Rényi和Bekenstein-Hawking熵,加深了对强场引力动力学的理解,促进了修改引力理论的研究。

英文摘要

The stability of geodesic orbits around a regular hairy black hole, in the gravitational decoupling setup, is investigated by employing Lyapunov exponents, which quantify the divergence rate of nearby trajectories in dynamical systems. Both timelike and null geodesics are addressed, probing the effect of the hair parameter on orbital stability. Deviations from the Schwarzschild solution have a significant influence on orbit stability, potentially providing observational signatures. Quasinormal modes of regular hairy black holes are calculated, and their thermodynamic properties are discussed. Both the Rényi and the Bekenstein-Hawking entropies are reported, deepening our understanding of gravitational dynamics in the strong-field regime, contributing to ongoing approaches to modified gravity.

2512.11981 2026-06-10 astro-ph.HE astro-ph.IM

Multimessenger Probes of the Supermassive Black Hole Binary Population: The Role of Pulsar Timing Arrays

多信使探测超大质量黑洞双星人口:脉冲星定时阵列的作用

Nima Laal, Stephen R. Taylor, Cayenne Matt, Kayhan Gultekin

AI总结 本文通过贝叶斯推断模拟数据,探讨脉冲星定时阵列如何通过引力波背景研究超大质量黑洞双星人口,发现其能显著降低双星硬化率和演化寿命的先验不确定性。

Comments Under review for publication

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Journal ref
Astrophys. J. 1004, 90 (2026)
AI中文摘要

通过推断引力波背景(GWB)从超大质量黑洞双星(SMBHBs)种群,脉冲星定时阵列(PTAs)使研究大质量黑洞成为可能。在许多方面,PTAs展示了多信使方法在天文学中的潜力:它们可以约束其他通过电磁观测难以约束的SMBHB种群特性,例如亚秒差距分离处的硬化机制。在本工作中,我们通过推断许多模拟PTA数据的实现,采用一个已成功应用于北美洲纳赫兹引力波观测站(NANOGrav)15年数据集的SMBHB模型,量化了这种多信使潜力。我们对200个现实的模拟NANOGrav数据集的分析显示,有超过50%的机会将SMBHB硬化率的先验不确定性减少超过50%,将SMBHB演化寿命的先验不确定性减少25-75%。此外,有88%的机会PTA数据可以将星系恒星质量函数(GSMF)特征质量变量的先验不确定性减少25-50%。对于M_BH--M_Bulge参数(在无红移演化的模型中)和GSMF的整体归一化参数,PTA数据在电磁观测约束之外只能提供有限的信息增益。我们的工作界定了电磁和引力波数据约束超大质量黑洞双星种群人口和动态的领域,为PTAs作为多信使天体物理学探测器对超大质量黑洞双星种群的影响提供了更清晰的图景。

英文摘要

By inferring the gravitational wave background (GWB) from a population of supermassive black hole binaries (SMBHBs), pulsar timing arrays (PTAs) enable the study of massive black holes. In many ways, PTAs manifest the promise of a multimessenger approach to astronomy: they can constrain SMBHB population characteristics that are otherwise difficult to constrain using electromagnetic observations, such as hardening mechanisms at sub-parsec separations. In this work, we quantify this multimessenger promise using Bayesian inference of many realizations of simulated PTA data, while adopting a model for the SMBHBs that has been successfully applied to the 15-year data set of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). Our analyses of 200 realistic, simulated NANOGrav data sets show that there is a greater than 50\% chance of reducing the prior uncertainty in the SMBHB hardening rate by more than 50\%, and in the SMBHB evolutionary lifetime by 25--75\%. Additionally, there is an 88\% chance that PTA data can reduce the prior uncertainty in the characteristic mass variable of the galaxy stellar mass function (GSMF) by 25--50\%. For $M_{\text{BH}}$--$M_{\text{Bulge}}$ parameters (in a model without redshift evolution) and the overall normalization parameter of the GSMF, PTA data can provide only marginal information gain beyond the constraints from electromagnetic observations. Our work delineates the domains over which electromagnetic and gravitational-wave data constrain the demographics and dynamics of the supermassive black-hole binary population, offering a clearer picture of the impact of population multi-messenger astrophysics probes with PTAs.

2512.11607 2026-06-10 eess.SY cs.SY

A Modeling and Optimization Framework for Fostering Modal Shift through the Integration of Tradable Credits and Demand-Responsive Autonomous Shuttles

一种通过整合可交易信用和需求响应型自动驾驶接驳车促进出行方式转换的建模与优化框架

Zenghao Hou, Ludovic Leclercq

AI总结 本文提出动态多模式均衡模型,整合可交易信用与需求响应型自动驾驶接驳车,优化出行方式转换及交通管理策略。

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Journal ref
Transportation Research Part C: Emerging Technologies, Volume 189, August 2026, Article 105755
AI中文摘要

可交易信用方案(TCS)通过限制私人汽车使用并允许信用交易来促进公共交通和共享交通的使用。然而,现有研究大多假设公共交通容量无限或共享交通的固定占用率,忽略了等待时间和时间成本的简化。本文开发了动态多模式均衡模型,考虑TCS监管下的运营约束和诱导等待时间。此外,大多数TCS研究假设固定交通供应,忽视了需求转换引发的供应响应。因此,本文提出通过部署需求响应型自动驾驶接驳车(DRAS)实现自适应供应管理,并开发双层优化框架,结合均衡模型共同优化TCS设计和DRAS的操作策略。本文将该框架应用于法国巴黎A10高速公路路段,研究需求-供应互动并评估TCS与DRAS联合实施的潜在效益。数值结果表明,在多模式均衡中建模运营特征和在TCS政策中纳入灵活供应对于降低总体广义成本至关重要。

英文摘要

Tradable Credit Schemes (TCS) promote the use of public and shared transport by capping private car usage while maintaining fair welfare outcomes by allowing credit trading. However, most existing studies assume unlimited public transit capacity or a fixed occupancy of shared modes, often neglecting waiting time and oversimplifying time-based costs by depending solely on in-vehicle travel time. These assumptions can overstate the system's performance with TCS regulation, especially when there are insufficient public or shared transport supplies. To address this, we develop a dynamic multimodal equilibrium model to capture operation constraints and induced waiting times under TCS regulation. The model integrates travelers' mode choices, credit trading, traffic dynamics, and waiting time, which depend on key operational features of service vehicles such as fleet size and capacity. Besides, most TCS studies assume fixed transport supply, overlooking supply-side responses triggered by demand shifts. Therefore, we further propose integrating adaptive supply management through the deployment of Demand-Responsive Autonomous Shuttles (DRAS) and developing a bi-level optimization framework that incorporates the equilibrium model to jointly optimize TCS design and operational strategies for the DRAS. We apply the framework to a section of the A10 highway near Paris, France, to examine demand-supply interactions and assess the potential benefits of jointly implementing TCS and DRAS. Numerical results demonstrate the importance of modeling operational features within multimodal equilibrium and incorporating flexible supply in TCS policies for mitigating overall generalized cost.

2512.10215 2026-06-10 quant-ph

Generating strong mechanical squeezing via combined squeezed vacuum field and two-tone driving

通过结合压缩真空场和双音驱动生成强机械压缩

Xiao-Jie Wu, Huan-Huan Cheng, Cheng-Hua Bai, Shao-Xiong Wu

AI总结 本文提出利用双音驱动与压缩真空场结合机制生成机械压缩态,实现红蓝调制比范围内机械压缩性能显著提升,揭示压缩场同时诱导位置压缩并促进动量压缩,且总压缩度随压缩参数r非线性增强,具有高操作灵活性和强鲁棒性。

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Journal ref
Advanced Quantum Technologies, 2026; 9: e00655
AI中文摘要

我们提出了一种基于双音驱动和压缩真空场结合机制生成机械压缩态的新方案。该创新方法在红蓝调制比整个范围内实现了机械压缩性能的显著提升。研究表明,压缩真空场不仅诱导机械振子的位置压缩,还通过相匹配促进动量压缩。此外,总压缩度随着压缩参数r的增加呈现非线性增强。机械压缩态相对于压缩相θ具有2π周期依赖性,提供高操作灵活性的实验实现。值得注意的是,该方案对腔体损耗和环境热噪声具有强鲁棒性,大大缓解了传统方法中严格参数匹配要求。

英文摘要

We propose a novel scheme for generating mechanical squeezed states based on the combined mechanism of a two-tone driving and a squeezed vacuum field. This innovative approach achieves a remarkable improvement in mechanical squeezing performance across the entire range of red/blue detuning ratios. Our study reveals that the squeezed vacuum field not only induces position squeezing of the mechanical oscillator but also facilitates momentum squeezing through phase matching. Moreover, the total squeezing degree exhibits nonlinear enhancement with the increasing of squeezing parameter $r$. The mechanical squeezed state exhibits a $2π$-periodic dependence in relation to the squeezing phase $θ$, offering experimental implementation with a high degree of operational flexibility. Notably, the scheme exhibits strong robustness against cavity dissipation and environmental thermal noise, substantially relaxing the strict parameter-matching requirements inherent in conventional approaches.

2507.00549 2026-06-10 cond-mat.soft physics.bio-ph

Charge Regulation Effect on Nanoparticles Interaction Mediated by Polyelectrolyte

电荷调节对由聚电解质介导的纳米颗粒相互作用的影响

Vijay Yadav, Prabhat Kumar Jaiswal, Rudolf Podgornik, Sunita Kumari

AI总结 研究电荷调节对由反电荷聚电解质介导的纳米颗粒相互作用的影响,通过混合CR分子动力学模拟发现电荷调节增强聚电解质吸附,导致弱排斥,而常电荷模型则产生更强的吸引力。

Comments Figures 7

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Journal ref
Macromolecules 2026, 59, 11, 6398-6409
AI中文摘要

利用带电聚合物精确控制表面电荷的能力对于许多纳米技术应用至关重要,能够设计和制造具有定制性质和功能的材料。本文研究了电荷调节(CR)对由反电荷聚电解质(PE)介导的两个纳米颗粒(NPs)相互作用的影响。为此,我们采用混合CR蒙特卡洛/分子动力学模拟框架,系统地探讨了pH、盐浓度和聚合物链长对纳米颗粒表面电荷行为的影响。此外,我们还进行了在恒定电荷(CC)条件下的分子模拟。研究结果表明,CR比CC情况增强了PE在纳米颗粒表面的吸附,其中聚合物桥接在广泛的纳米颗粒表面分离范围内占主导地位。这种增强的吸附在CR条件下导致由渗透力驱动的弱净排斥。相比之下,CC模型由于桥接力产生更强的净吸引力。此外,我们发现CR效应在低盐浓度下更为显著,而在高盐浓度下,反离子屏蔽在CR和CC情况下均占主导地位,削弱了CR效应。这些发现突显了在复杂生物化学环境中表征纳米颗粒相互作用时,纳入电荷调节的重要性,特别是在低盐浓度情况下。

英文摘要

The ability to precisely control surface charge using charged polymers is fundamental to many nanotechnology applications, enabling the design and fabrication of materials with tailored properties and functionalities. Here, we study the effect of charge regulation (CR) on the interaction between two nanoparticles (NPs) mediated by an oppositely charged polyelectrolyte (PE) in an electrolyte solution. To this end, we employ a hybrid CR Monte Carlo / molecular dynamics simulation framework to systematically explore the effects of pH, salt concentration, and polymer chain length on NP surface charge behavior. For comparison, we also conduct molecular simulations under constant charge (CC) conditions. Our results reveal that CR enhances PE adsorption onto NP surfaces compared to the CC case, where polymer bridging dominates across a wide range of NP intersurface separations. This enhanced adsorption under CR leads to a weak net repulsion driven by osmotic forces. In contrast, the CC model yields a stronger net attraction due to the bridging force. Furthermore, we find that the CR effects are more pronounced at low salt concentration, whereas at high salt concentration, counterion screening dominates in both CR and CC cases, diminishing the CR effect. These findings highlight the importance of incorporating charge regulation in characterizing nanoparticle interactions within a complex biochemical environment, particularly in low salt concentrations.

2309.12092 2026-06-10 math.MG

Jung-type Inequalities and Blaschke-Santaló Diagrams for Different Diameter Variants

Jung型不等式与Blaschke-Santaló图示法对于不同直径变体

René Brandenberg, Mia Runge

AI总结 本文研究了关于凸体的圆外径与直径的几何不等式,涉及内径和Minkowski不对称性。不同凸体直径定义在非对称度量下会分解,对应于度量的不同对称化方法。

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AI中文摘要

我们研究了关于圆外径和直径相对于一般度量的几何不等式,部分还涉及内径和Minkowski不对称性。存在多种定义凸体直径的方法,当考虑非对称度量时这些定义会分解。这些定义对应于度量的不同对称化,即度量$C$与其原点反射$-C$的平均方法。

英文摘要

We study geometric inequalities for the circumradius and diameter with respect to general gauges, partly also involving the inradius and the Minkowski asymmetry. There are a number of options for defining the diameter of a convex body that fall apart when we consider non-symmetric gauges. These definitions correspond to different symmetrizations of the gauge, i.e. means of the gauge $C$ and its origin reflection $-C$.

2511.20379 2026-06-10 cond-mat.mes-hall cond-mat.mtrl-sci

Spin current symmetries generated by GdFeCo ferrimagnet across its magnetisation compensation temperature

由GdFeCo铁磁体在磁化补偿温度跨过时生成的自旋电流对称性

Héloïse Damas, Michel Hehn, Juan-Carlos Rojás-Sanchez, Sébastien Petit-Watelot

AI总结 研究GdFeCo铁磁体在不同温度下自旋电流对称性,通过自旋扭矩铁磁共振光谱技术分离自旋霍尔效应和自旋异常霍尔效应贡献,揭示自旋电流在磁化补偿点的行为特性。

Comments 10 pages, 6 figures, 1 table

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AI中文摘要

铁磁体由反铁磁耦合的磁子晶格组成,其净磁化可通过温度调节。本文研究了GdFeCo铁磁体在固定浓度和宽温度范围内生成的自旋电流对称性,包括磁化补偿点。利用互补技术,基于自旋扭矩铁磁共振光谱,分离自旋霍尔效应(SHE)和自旋异常霍尔效应(SAHE)的贡献。我们显示,两种机制产生的扭矩在磁化补偿温度跨过时保持符号不变,且SAHE驱动的阻尼类扭矩与SHE驱动的项符号相反。我们建议两种效应源自不同的电子子系统:SHE来自Gd 5d电子,SAHE来自FeCo 3d电子。因此,SHE的符号对磁化状态不敏感,而SAHE的符号在补偿点不翻转,重现了我们的观测。这些见解阐明了铁磁体中子晶格间的相互作用,并突显了铁磁自旋电流在相邻层或自身内生成自旋扭矩的潜力。

英文摘要

Ferrimagnets, composed of antiferromagnetically coupled magnetic sublattices whose net magnetisation can be tuned by temperature, offer a unique platform for probing the symmetry of the spin currents they generate and for identifying the sublattice contributions to these currents. Here, we investigate the spin current symmetries produced by GdFeCo ferrimagnet at a fixed concentration and across a broad temperature range, including the magnetisation compensation point. Using complementary techniques based on spin-torque ferromagnetic resonance spectroscopy, we separate the contributions of the spin Hall effect (SHE) and the spin anomalous Hall effect (SAHE). We show that the torques arising from both mechanisms retain their sign across the magnetisation compensation temperature, and that the SAHE-driven damping-like torque has the opposite sign to the SHE-driven term. We suggest that both effects originates from distinct electronic subsystems: the SHE emerging from Gd 5d electrons, and the SAHE from FeCo 3d electrons. Consequently, the SHE sign remains insensitive to the magnetisation state, whereas the SAHE sign does not invert at compensation, reproducing our observations. Together, these insights clarify the interplay between sublattices in ferrimagnetic spin transport and highlight the potential of ferrimagnetic spin currents to generate spin torques in adjacent layers or within the ferrimagnet itself.

2512.01907 2026-06-10 cond-mat.mtrl-sci

First-principles band alignment engineering in polar and nonpolar orientations for wurtzite AlN, GaN, and B$_x$Al$_{1-x}$N alloys

极性和非极性取向下 wurtzite 结构 AlN、GaN 和 B$_x$Al$_{1-x}$N 合金的原理计算能带对齐工程

Cody L Milne, Arunima K Singh

AI总结 本文通过密度泛函理论等方法计算了B$_x$Al$_{1-x}$N在不同取向下的能带对齐,发现低xB$_x$Al$_{1-x}$N/AlN具有近零价带对齐,高xB$_x$Al$_{1-x}$N则呈现I型或II型对齐,为高电子迁移率晶体管和紫外发光二极管设计提供指导。

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AI中文摘要

硼铝氮化物(B$_x$Al$_{1-x}$N)因其超宽禁带、高热稳定性和与其他III-氮化物半导体的兼容性,成为下一代电子和光电子器件的有前途材料。尽管其潜力巨大,但B$_x$Al$_{1-x}$N的能带对齐仍鲜为人知,这对于器件设计至关重要。在本研究中,我们利用密度泛函理论、许多体微扰理论、GW0方法和一种新的钝化方案,计算了非极性(a面)和极性(c面)B$_x$Al$_{1-x}$N的价带和导带对齐,并将其与AlN和GaN的进行了比较。结果发现,低xB$_x$Al$_{1-x}$N/AlN具有近零价带对齐,而较高成分(x > 0.333)则呈现I型或II型能带对齐。能带对齐还显示出对表面极性和B$_x$Al$_{1-x}$N结构四面体畸变的显著依赖性。计算得到的偏移量与现有实验数据良好一致。由于其低价带对齐和高导带对齐,B$_x$Al$_{1-x}$N/AlN异质结适合用于高电子迁移率晶体管和紫外发光二极管。本研究确定的B$_x$Al$_{1-x}$N能带对齐为将这些超宽禁带合金整合到先进半导体技术中提供了必要的设计指南。

英文摘要

Boron aluminum nitride (B$_x$Al$_{1-x}$N) is a promising material for next-generation electronic and optoelectronic devices due to its ultra-wide bandgap, high thermal stability, and compatibility with other III-nitride semiconductors. Despite its potential, the band alignments of B$_x$Al$_{1-x}$N remain largely unexplored, although this information is essential for device design. In this study, we compute the valence and conduction band alignments of nonpolar ($a$-plane) and polar ($c$-plane) B$_x$Al$_{1-x}$N, and compare them with those of AlN and GaN. Using density functional theory, many-body perturbation theory, $GW_0$ method, and a novel passivation scheme, we find that they have near-zero valence band alignments for low-$x$ B$_x$Al$_{1-x}$N/AlN, while higher compositions ($x > $0.333) exhibit type I or II band alignments. The band alignments also show a notable dependence on surface polarity and the tetrahedral distortion of the B$_x$Al$_{1-x}$N structures. Our computed offsets are in good agreement with available experimental data. Due to their low valence band alignments and higher conduction band alignments, the B$_x$Al$_{1-x}$N/AlN heterostructures could be well suited for high-electron-mobility transistors and ultraviolet light-emitting diodes. The band alignments of B$_x$Al$_{1-x}$N determined in this study provide essential design guidelines for integrating these ultra-wide bandgap alloys into advanced semiconductor technologies.

2511.22017 2026-06-10 cs.CR

POLARIS: Cross-Domain Access Control via Verifiable Identity and Policy-Based Authorization

POLARIS:通过可验证身份和基于策略的授权实现跨域访问控制

Aiyao Zhang, Xiaodong Lee, Zhixian Zhuang, Jiuqi Wei, Yufan Fu, Botao Peng

AI总结 本文提出POLARIS框架,解决传统访问控制在跨域场景中的身份分散、隐私泄露等问题,通过可验证身份和轻量级策略语言实现隐私保护和灵活授权。

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Journal ref
Proc. 2025 IEEE 24th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom), pp. 1489-1498, 2025
AI中文摘要

访问控制是一种安全机制,旨在确保只有授权用户才能访问特定资源。跨域访问控制涉及在不同组织、机构或应用之间访问资源。然而,传统访问控制在集中化环境中将认证和授权分开处理,面临身份分散、隐私泄露和多样化权限需求的挑战,无法适应跨域场景。因此,需要一种新的访问控制机制,能够自主控制用户身份和资源,满足跨域场景中隐私保护的认证和灵活授权需求。为了解决跨域访问控制的挑战,我们提出POLARIS,一种统一且可扩展的架构,能够实现基于策略的、可验证且隐私保护的跨域访问控制。POLARIS具有结构化承诺机制,用于可靠、细粒度、基于策略的身份披露。它进一步引入VPPL,一种轻量级策略语言,支持绑定评估的可选属性。专门的会话级安全机制确保认证与访问之间的绑定,增强保密性和对重放攻击的抵抗力。我们实现了一个工作原型并进行了全面实验,证明POLARIS在异构域中提供了可扩展、隐私保护和互操作的访问控制。我们的结果突显了POLARIS在支持安全且隐私保护的访问控制方面的实际可行性,特别是在去中心化、跨域环境中。

英文摘要

Access control is a security mechanism designed to ensure that only authorized users can access specific resources. Cross-domain access control involves access to resources across different organizations, institutions, or applications. Traditional access control, however, which handles authentication and authorization separately in centralized environments, faces challenges in identity dispersion, privacy leakage, and diversified permission requirements, failing to adapt to cross-domain scenarios. Thus, there is an urgent need for a new access control mechanism that empowers autonomous control over user identity and resources, addressing the demands for privacy-preserving authentication and flexible authorization in cross-domain scenarios. To address cross-domain access control challenges, we propose POLARIS, a unified and extensible architecture that enables policy-based, verifiable and privacy-preserving access control across different domains. POLARIS features a structured commitment mechanism for reliable, fine-grained, policy-based identity disclosure. It further introduces VPPL, a lightweight policy language that supports issuer-bound evaluation of selectively revealed attributes. A dedicated session-level security mechanism ensures binding between authentication and access, enhancing confidentiality and resilience to replay attacks. We implement a working prototype and conduct comprehensive experiments, demonstrating that POLARIS effectively provides scalable, privacy-preserving, and interoperable access control across heterogeneous domains. Our results highlight the practical viability of POLARIS for enabling secure and privacy-preserving access control in decentralized, cross-domain environments.

2511.21308 2026-06-10 cond-mat.mes-hall

Unveiling Micrometer-Range Spin-Wave Transport in Artificial Spin Ice

揭示人工自旋冰中微米级自旋波传输

Syamlal Sankaran Kunnath, Mateusz Zelent, Pawel Gruszecki, Maciej Krawczyk

AI总结 研究通过混合人工自旋冰系统实现微米级自旋波传输,利用交换耦合和倏逝波隧道效应,突破传统自旋冰的限制,为自旋波在摩擦自旋冰系统中的研究和类比信号处理奠定基础。

Comments 7 pages main paper paper text and 4 main figures; 6 pages supporting information text and 8 supporting figures

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AI中文摘要

人工自旋冰(ASI)系统表现出摩擦、磁单极子状态和狄拉克弦等有趣现象,但探索其中的波现象困难,因为支配其相互作用的弱偶极子耦合。在本研究中,我们展示了在多层铁磁薄膜基础上的混合ASI系统中相干自旋波传播,该系统具有垂直磁各向异性的多层铁磁薄膜和其中嵌入的平面磁化纳米元件。我们证明该系统通过子系统间的交换耦合和倏逝自旋波隧道效应,实现了自旋波在1微米距离的传输。该系统克服了传统ASI中仅依赖偶极子相互作用的限制,同时保留了其基本性质。因此,它为研究摩擦ASI系统中的自旋波现象提供了平台,并为利用自旋波进行类比信号处理铺平了道路。

英文摘要

Artificial spin ice (ASI) systems exhibit fascinating phenomena, such as frustration and the formation of magnetic monopole states, and Dirac strings. However, exploring the wave phenomena in these systems is elusive due to the weak dipolar coupling that governs their interactions. In this study, we demonstrate coherent spin-wave propagation in an hybrid ASI system, which is based on a multilayered ferromagnetic thin film with perpendicular magnetic anisotropy and in-plane magnetized nanoelements embedded within it. We show that this system enables spin-wave transmission over a one-micrometer distance via exchange-mediated coupling between subsystems and evanescent spin-wave tunneling through the out-of-plane magnetized parts. This system overcomes the limitations of purely dipolar interactions in standard ASIs while preserving their fundamental properties. Thus, it provides a platform for studying spin-wave phenomena in frustrated ASI systems and paves the way for exploiting them in analog signal processing with spin waves.

2511.03663 2026-06-10 astro-ph.GA astro-ph.IM

3D Full Spectrum Fitting: Algorithm Comparison

三维全谱拟合:算法比较

Prashin Jethwa, Simon Hubmer, Ronny Ramlau, Glenn Van de Ven

AI总结 本文比较了两种算法在三维全谱拟合中的性能,发现Bayes-LOSVD在考虑空间相关性时提升了动能恢复精度,而PNKR在SNR>40时能更准确恢复动能,并能推断动能与人口之间的趋势。

Comments Submitted to A&A

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Journal ref
A&A 710, A135 (2026)
AI中文摘要

全谱拟合是提取恒星动力学和人口测量的主要方法,而三维方法涉及对积分场光谱(IFS)数据的同时建模。本文介绍了并比较了两种算法:投影Nesterov Kaczmarz重建方法(PNKR)和改进版的Bayes-LOSVD软件。研究旨在理解两种算法的优缺点,并评估三维方法对恒星推断的影响。通过在信号噪声比(SNR)20-200范围内的模拟IFS数据应用两种恢复算法,评估恢复质量与真实值的对比。在Bayes-LOSVD中考虑空间相关性显著提高了动能恢复的准确性和精度。而PNKR的三维建模未提供比一维拟合更显著的改进,但SNR>40时总体动能恢复最准确。此外,通过同时建模动能和人口的联合分布,PNKR能成功推断两者之间的趋势,如局部金属licity-速度趋势,但绝对金属licity存在显著偏差。本文结论表明,Bayes-LOSVD的三维建模和PNKR的联合动能-人口分析在恒星结构检测和表征中具有实用性。

英文摘要

Full spectrum fitting is the prevailing method for extracting stellar kinematic and population measurements from 1D galaxy spectra. 3D methods refer to analysis of Integral Field Spectroscopy (IFS) data where spatial and spectral dimensions are modelled simultaneously. While several 3D methods exist for modelling gas structures there has been less investigation into the more computationally demanding problem of 3D full spectrum fitting for stellar recoveries. This work introduces and compares two algorithms for this task: the Projected Nesterov Kaczmarz Reconstruction method (PNKR) and a version of the Bayes-LOSVD software which has been modified to account for spatial correlations. We aim to understand strengths and weaknesses of both algorithms and assess the impact of 3D methods for stellar inferences. We apply both recovery algorithms to a mock IFS data over a signal-to-noise ratio (SNR) range from 20-200 and evaluate the quality of the recoveries compared to the known ground truth. Accounting for spatial correlations in Bayes-LOSVD significantly improved the accuracy and precision of kinematic recoveries. 3D modelling with PNKR did not provide any significant improvement over 1D fits however, for SNR>40, PNKR did recover the most accurate kinematics overall. Additionally, by modelling the joint distribution over kinematics and populations, PNKR could successfully infer trends between these quantities e.g. inferring local metallicity-velocity trends, albeit with a significant bias on the absolute metallicity. Having demonstrated advantages of (i) 3D modelling with Bayes-LOSVD, and (ii) joint kinematic-population analyses with PNKR, we conclude that both methodological advances will prove useful for detecting and characterising stellar structures from IFS data.

2511.02904 2026-06-10 quant-ph cond-mat.stat-mech hep-lat nucl-th

Classical shadows for sample-efficient measurements of gauge-invariant observables

用于规范不变可观测量高效测量的经典阴影

Jacob Bringewatt, Henry Froland, Andreas Elben, Niklas Mueller

AI总结 针对Z2格点规范理论,开发三种经典阴影协议,利用对称性实现样本复杂度指数级提升,并分析电路深度与样本复杂度的权衡。

Comments 21 pages, 10 figures. Updated to journal version: modified abstract, expanded discussion, clarified certain points, changed license

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Journal ref
Quantum 10, 2127 (2026)
AI中文摘要

经典阴影提供了一个通用框架,通过重复的随机测量来估计量子态的许多性质,而无需完整的量子态层析。当先验信息可用时,例如态和算符的对称性知识,可以利用这些知识显著提高样本效率。在这项工作中,我们为$\mathbb{Z}_2$格点规范理论开发了三种经典阴影协议,其中对偶公式允许对资源需求进行严格分析,包括电路深度和样本复杂度。我们的方法可以在样本复杂度上比对称性无关的方法提供指数级改进,尽管以增加电路复杂度为代价。虽然我们的分析限于$\mathbb{Z}_2$格点规范理论,但我们的方法为更一般的格点规范理论模型提供了蓝图,这些模型目前处于量子模拟努力的前沿。

英文摘要

Classical shadows provide a versatile framework for estimating many properties of quantum states from repeated, randomly chosen measurements without requiring full quantum state tomography. When prior information is available, such as knowledge of symmetries of states and operators, this knowledge can be exploited to significantly improve sample efficiency. In this work, we develop three classical shadow protocols for $\mathbb{Z}_2$ lattice gauge theory, where a dual formulation enables a rigorous analysis of resource requirements, including both circuit depth and sample complexity. Our approaches can offer exponential improvements in sample complexity over symmetry-agnostic methods, albeit at the cost of increased circuit complexity. While our analysis is restricted to $\mathbb{Z}_2$ lattice gauge theory, our approach offers a blueprint for similar protocols for more general lattice gauge theory models which are currently at the forefront of quantum simulation efforts.

2510.23367 2026-06-10 astro-ph.HE

From Rare Events to a Population: Discovering Overlooked Extragalactic Magnetar Giant Flare Candidates in Archival Fermi Gamma-ray Burst Monitor Data

从稀有事件到一个群体:在阿基米德费米伽马射线暴监测器数据中发现被忽视的 extragalactic 磁星巨爆发候选者

Aaron C. Trigg, Eric Burns, Michela Negro, Suman Bala, P. N. Bhat, William H. Cleveland, Dmitry D. Frederiks, Adam Goldstein, Boyan A. Hristov, Daniel Kocevski, Niccolò Di Lalla, Stephen Lesage, Bagrat Mailyan, Eliza Neights, Nicola Omodei, Oliver J. Roberts, Lorenzo Scotton, Dmitry S. Svinkin, Joshua Wood

AI总结 本文通过改进方法在费米GBM数据中发现4个新候选者,扩展了已知的13个磁星巨爆发,建立了统计模型并推断出事件体积率,揭示磁星可能多次爆发的特性。

详情
Journal ref
A&A 710, A139 (2026)
AI中文摘要

磁星巨爆发(MGFs)是来自高磁化中子星的罕见、极亮伽马射线爆发。这些事件难以识别,因为在 extragalactic 距离下,它们可能与其他天体物理现象相似。迄今为止,只有少数几个被确认,限制了我们对其起源和物理性质的理解。本研究旨在扩展已知事件样本,并更详细地表征其观测特征和内在性质,同时引入显著改进的识别和分析方法。当应用于费米伽马射线空间望远镜上的伽马射线暴监测器(GBM)存档数据时,这种方法将四个此前未识别的事件加入已知样本,使总数扩展到13个MGFs。这展示了方法的有效性,并表明还有更多MGFs可能隐藏在现有的伽马射线暴目录中。我们利用扩展的样本来更深入地了解MGFs的更大群体。我们开发了一个统计建模框架,结合了之前考虑的数据与现代Fermi/GBM观测。该模型考虑了仪器灵敏度和事件特征的预期多样性。我们推断出事件体积率超过1.2×10^44 erg的R_MGF=5.5±4.5/−2.7×10^5 Gpc^{-3} yr^{-1}。结果表明,单个磁星必须在其生命周期内产生多次爆发,强化了这些是重复现象而非单一爆炸事件的观点。扩大已知MGFs样本有助于我们理解磁星及其在其他天体物理现象中的作用,包括可能与快速射电暴、引力波以及极端天体物理环境中重元素形成的相关性。

英文摘要

Magnetar giant flares (MGFs) are rare, extremely bright bursts of gamma-rays from highly magnetized neutron stars. These events are challenging to identify because, at extragalactic distances, they can appear similar to other astrophysical phenomena. Only a handful have been confidently identified to date, limiting our understanding of their origin and physical properties. This study focuses on expanding the sample of known events and enabling a more detailed characterization of their observational features and intrinsic properties, while introducing significant improvements in the methods used to identify and analyze them. When applied to archival data from the Gamma-ray Burst Monitor (GBM) on the \Fermi Gamma-ray Space Telescope, this approach added four previously unidentified events the known sample, expanding the total to 13 MGFs. This demonstrates both the effectiveness of the method and the likelihood that additional MGFs remain hidden in existing gamma-ray burst catalogs. We utilize this expanded sample to gain a deeper understanding of the broader population of MGFs. We develop a statistical modeling framework that combines previously considered data with modern observations from Fermi/GBM. The model accounts for instrumental sensitivity and the expected diversity in event characteristics. We infer a volumetric rate of events above $1.2\times10^{44}\,\rm{erg}$ of $R_{MGF}=5.5^{+4.5}_{-2.7}\times10^5\rm{Gpc^{-3}yr^{-1}}$. The results show that individual magnetars must produce multiple flares throughout their lifetimes, reinforcing the idea that these are recurring phenomena rather than singular explosive events. Expanding the sample of known MGFs improves our understanding of magnetars and their role in other astrophysical phenomena, including possible links to fast radio bursts, gravitational waves, and the creation of heavy elements in extreme astrophysical environments.

2510.09069 2026-06-10 physics.hist-ph

Two Types of Natural Kind Discovery: Nobel Meets Kuhn

两种自然种类的发现:诺贝尔奖与库恩

Samuel Schindler

AI总结 本文通过诺贝尔物理学奖得主的发现,探讨库恩提出的两种自然种类发现类型,并提出科学信用分配的规范结论。

Comments forthcoming in Philosophy of Science

详情
Journal ref
Philos. sci. 93 (2026) 334-352
AI中文摘要

哲学家们在经典“发现情境”中对思想发现的发现已有大量讨论。然而,关于“世界中的事物”发现的性质问题却鲜有探讨。T.S.库恩为这一问题提供了被忽视的答案。本文表明,过去53年获得诺贝尔物理学奖的发现符合库恩的基本前提及其对两种自然种类发现类型的区分。同时,本文还为科学中的信用分配提出了规范性结论。

英文摘要

Philosophers have spilled much ink over the discovery of ideas in the classical 'context of discovery'. However, there has been little engagement with the question of what constitutes a discovery of 'things in the world'. A much-overlooked answer to this question is provided by T.S. Kuhn. In this paper, I show that discoveries awarded with a Nobel Prize in Physics in the past 53 years accord with a basic premise of Kuhn's account and his distinction between two types of natural kind discoveries. I also draw normative conclusions for credit attribution in science.

2510.17005 2026-06-10 cs.NE

Bombardier Beetle Optimizer: A Novel Bio-Inspired Algorithm for Global Optimization

爆炸 Beetle 优化器:一种新颖的生物启发算法用于全局优化

Hisham A. Shehadeh, Mohd Yamani Idna Idris, Iqbal H. Jebril

AI总结 本文提出了一种名为爆炸 Beetle 优化器(BBO)的新型生物启发算法,受爆炸 Beetle 的防御和逃避机制启发,用于解决全局优化问题。

Comments Journal paper

详情
Journal ref
In IEEE 2026 2nd International Conference on Computational Intelligence Approaches and Applications (ICCIAA)
AI中文摘要

本文提出了一种新颖的生物启发优化算法,称为爆炸 Beetle 优化器(BBO)。这种生物具有智能特性,能够防御和逃避捕食者。前者原理受到爆炸 Beetle 对捕食者防御机制的启发,当它感到受到威胁时,会触发有毒化学物质喷射。该反应发生在其腹部内的专用反应室中,包括一个精心调节的酶促机制,其中包括热水蒸汽、氧气和刺激性物质如对苯二醌。此外,所提出的BBO还模拟了爆炸 Beetle 逃避捕食者的机制,它能够计算与捕食者之间的距离并飞走。BBO 在优化进化计算(CEC 2017)测试集上进行了测试。此外,它还与一些著名的元启发式优化算法进行了比较,包括切尔诺贝利灾难优化器(CDO)、灰狼优化器(GWO)、粒子群优化(PSO)、百慕大三角优化器(BTO)、精子群优化(SSO)和引力搜索算法(GSA)。本文的结果证明了BBO在收敛速度和结果质量方面的效率,优于其他算法。

英文摘要

In this paper, a novel bio-inspired optimization algorithm is proposed, called Bombardier Beetle Optimizer (BBO). This type of species is very intelligent, which has an ability to defense and escape from predators. The principles of the former one is inspired by the defense mechanism of Bombardier Beetle against the predators, which the Bombardier Beetle triggers a toxic chemical spray when it feels threatened. This reaction occurs in a specialized reaction chamber inside its abdomen and includes a well regulated enzymatic mechanism, which comprises hot water vapor, oxygen, and irritating substances like p-benzoquinones. In addition, the proposed BBO simulates also the escape mechanism of Bombardier Beetle from predator, which it has the ability to calculate its distance from predator and it can fly away. The BBO is tested with optimizing Congress on Evolutionary Computation (CEC 2017) test bed suites. Moreover, it is compared against well-known metaheuristic optimization algorithms includes Chernobyl Disaster Optimizer (CDO), Grey Wolf Optimizer (GWO), Particle Swarm Optimization (PSO), Bermuda Triangle Optimizer (BTO), Sperm Swarm Optimization (SSO) and Gravitational Search Algorithm (GSA). The outcomes of this paper prove the BBO's efficiency in which outperforms the other algorithms in terms of convergence rate and quality of results.

2510.16733 2026-06-10 cond-mat.mtrl-sci

Fractional Quantum Multiferroics from Coupling of Fractional Quantum Ferroelectricity and Altermagnetism

从分数量子铁电性和交替磁性耦合获得分数量子多铁性

M. Q. Dong, B. Liu, Z. H. Dai, Zhi-Xin Guo, Hongjun Xiang, Xin-Gao Gong

AI总结 研究提出通过分数量子多铁性实现强磁电耦合,发现电控自旋调控及室温高磁电性能,揭示多铁材料新途径。

Comments 13 pages, 4 figures

详情
Journal ref
Phys. Rev. Lett. 136, 136702 (2026)
AI中文摘要

多铁性材料结合铁电和磁序,为下一代电子器件提供平台,但单相材料中铁电和磁性机制的竞争限制了性能,通常导致室温下弱磁电耦合。本文提出分数量子多铁性(FQMF)概念,通过分数量子铁电性(FQFE)与交替磁性(AM)耦合实现强磁电耦合。对称分析显示,反转FQFE极化必然反转AM自旋分裂在宇称时间(PT)或时间反演(Tτ)操作下。最小紧束缚模型再现该效应,证明电控自旋调控无需旋转Néel矢量。第一性原理计算进一步识别二维和三维材料家族,包括本征MnTe、Cr₂S₃、Mn₄Bi₃NO₁₅及二维AB₂双层如MnX₂(X=Cl, Br, I)、CoCl₂、CoBr₂和FeI₂。值得注意的是,MnTe具有高Néel温度(≈300 K)和大电控自旋分裂(≈0.8 eV),展示出超过传统多铁材料的室温磁电性能。为进一步展示技术潜力,提出基于MnTe的电场控制FQMF隧道结,实现隧道磁电阻超过300%。本工作确立FQMF作为实现室温强磁电耦合的新型途径,开辟电压控制自旋电子学的新领域。

英文摘要

Multiferroics, which combine ferroelectric and magnetic order, offer a transformative platform for next-generation electronic devices. However, the intrinsic competition between the mechanisms driving ferroelectricity and magnetism in single-phase materials severely limits their performance, typically resulting in weak magnetoelectric coupling at room temperature. Here, we propose a solution to this long-standing challenge through the novel concept of fractional quantum multiferroics (FQMF), where strong magnetoelectric coupling is naturally realized by coupling fractional quantum ferroelectricity (FQFE) with altermagnetism (AM). Symmetry analysis shows that reversing the FQFE polarization necessarily inverts the AM spin splitting under parity-time ($\mathcal{PT}$) or time-reversal ($\mathcal{T}τ$) operations. A minimal tight-binding model reproduces this effect, demonstrating electrically driven spin control without rotating the Néel vector. First-principles calculations further identify a broad family of candidate materials in two and three dimensions including bulk MnTe, Cr$_2$S$_3$, Mn$_4$Bi$_3$NO$_{15}$ and two-dimensional AB$_2$ bilayers such as MnX$_2$ (X=Cl, Br, I), CoCl$_2$, CoBr$_2$, and FeI$_2$. Notably, MnTe exhibits a high Néel temperature ($\sim$300 K) and a large electrically switchable spin splitting ($\sim$0.8 eV), demonstrating room-temperature magnetoelectric performance that surpasses that of conventional multiferroics. To further showcase the technological potential, we propose an electric-field-controlled FQMF tunnel junction based on MnTe that achieves tunneling magnetoresistance exceeding 300\%. This work establishes FQMF as a distinct and promising route to achieving room-temperature strong magnetoelectric coupling, opening a new avenue for voltage-controlled spintronics.