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2605.20893 2026-05-21 quant-ph

Enhancing Phase Estimation in a Hybrid Interferometer via Kerr Nonlinearity and Photon Subtraction

通过Kerr非线性与光子子traction增强混合干涉仪的相位估计

Lifen Guo, Qingqian Kang, Zekun Zhao, Jifeng Sun, Teng Zhao, Cunjin Liu, Xin Su, Liyun Hu

AI总结 本文提出了一种高精度相位估计方案,通过结合Kerr非线性相位移器和多光子子traction操作,实现了超越标准量子极限和常规海森堡标度的相位灵敏度,接近超海森堡标度。

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AI中文摘要

我们提出了一种高精度相位估计方案,通过协同结合Kerr非线性相位移器和多光子子traction操作,在混合干涉仪中实现高精度相位估计。使用相干态和真空态作为输入资源,我们通过锁相检测系统性地评估了相位灵敏度,并分析了在理想和有损条件下量子 Fisher 信息以及量子 Cramér-Rao 绑定。我们的结果表明,Kerr 非线性和多光子子traction 的联合使用相较于单独使用任何一种技术具有显著优势。所提出的方案使相位灵敏度超越标准量子极限,超过常规海森堡标度(1/N),并接近超海森堡标度(1/N²)——Kerr 非线性的直接结果。更精确地说,超海森堡标度∝1/N²是k=2 Kerr 非线性允许的最终精度极限,并不违反线性相位积累的基本海森堡极限。即使在中等内部光子损失下,系统仍能保持高精度并表现出增强的退相干鲁棒性。Kerr 非线性引入了与光子数平方成正比的强度依赖相位移,而多光子子traction 制造非高斯态以加强相位信息提取。与基于混合干涉仪或SU(1,1)干涉仪的现有方案相比,我们的架构实现了更高的精度和更强的损失鲁棒性。所有组件都可通过当前量子光学技术实验实现。这项工作为实际高精度量子计量和量子传感提供了有前景的途径。

英文摘要

We propose a high-precision phase estimation scheme in a hybrid interferometer by synergistically combining a Kerr nonlinear phase shifter and multi-photon subtraction operations. Using a coherent state and a vacuum state as input resources, we systematically evaluate the phase sensitivity via homodyne detection and analyze the quantum Fisher information as well as the quantum Cramér-Rao bound under both ideal and lossy conditions. Our results show that the joint integration of Kerr nonlinearity and multi-photon subtraction yields remarkable advantages over either technique used alone. The proposed scheme enables the phase sensitivity to surpass the standard quantum limit, exceed the conventional Heisenberg scaling ($1/N$), and approach the super-Heisenberg scaling ($1/N^{2}$)-a direct consequence of Kerr nonlinearity. More precisely, the super-Heisenberg scaling $\propto $ $1/N^{2}$ is the ultimate precision limit permitted by the $k=2$ Kerr nonlinearity and does not violate the fundamental Heisenberg limit for linear phase accumulation. Even under moderate internal photon loss, the system maintains high precision and exhibits enhanced robustness to decoherence. The Kerr nonlinearity introduces an intensity-dependent phase shift proportional to the squared photon number, while multi-photon subtraction tailors non-Gaussian states to strengthen phase information extraction. Compared with existing schemes based on hybrid interferometers or SU(1,1) interferometers, our architecture achieves superior precision and stronger loss resilience. All components are experimentally accessible with current quantum optical technologies. This work provides a promising route for practical high-precision quantum metrology and quantum sensing.

2605.20890 2026-05-21 cond-mat.mtrl-sci

Transferable 3D Convolutional Neural Networks for Elastic Constants Prediction in Nanoporous Metals

可迁移的3D卷积神经网络用于纳米多孔金属弹性常数预测

Sergei Zorkaltsev, Rafał Topolnicki, Tal-El Carmon, Santhosh Mathesan, Paweł Dłotko, Dan Mordehai, Maciej Harańczyk

AI总结 本文研究了如何利用可迁移的3D卷积神经网络预测纳米多孔金属的弹性常数,通过分子动力学模拟生成了大量数据,并比较了不同预测方法的性能,最终展示了模型的鲁棒性和在大规模数据集上的应用效果。

Comments 20 pages, 7 figures, supplement, dedicated github repo

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Journal ref
Materials & Design, Volume 260, 2025, 114896
AI中文摘要

纳米多孔金属的拓扑结构对其机械响应至关重要。在本工作中,我们生成了6000个金和422个银纳米多孔结构,并通过分子动力学模拟计算了弹性模量的三个分量,共得到19263个数据点。本研究比较了两种预测弹性模量的方法:一种是基于预计算拓扑描述符的全连接神经网络,以及几种从计算机视觉中借鉴的3D卷积神经网络架构。3D CNNs在基于描述符的基线模型(R²=0.704)之上表现更优,其中表现最佳的DenseNet-201架构达到R²=0.955。此外,还研究了训练网格分辨率、数据集大小以及将描述符整合到模型中的影响。我们进一步通过迁移学习展示了模型的鲁棒性:预训练模型在更小的致密金结构数据集和致密银结构数据集上进行了微调。最后,训练好的模型被用于评估100,000个随机生成的纳米多孔金结构,并识别出帕累托最优设计。

英文摘要

The topology of nanoporous metals is crucial for determining their mechanical response. In this work, we generated 6,000 gold and 422 silver nanoporous structures and calculated three components of elastic modulus with Molecular Dynamics simulations, resulting in 19,263 data points. This study compared two distinct approaches of predicting elastic modulus: a Fully-Connected neural network trained on precomputed topological descriptors, and several 3D Convolutional neural network architectures adapted from computer vision. The 3D CNNs outperformed the descriptor-based baseline model ($R^2 = 0.704$), with to-performing DenseNet-201 architecture achieving $R^2 = 0.955$. Additionally, the effects of training grid resolution, dataset size, and descriptor integration into a model were investigated. We further demonstrated model robustness through Transfer learning: a pretrained model was fine-tuned on a much smaller dataset of denser gold structures and the dataset of denser silver structures. Finally, the trained model was employed to evaluate the mechanical properties of 100,000 stochastic nanoporous gold structures and identify the Pareto optimal designs.

2605.20888 2026-05-21 gr-qc

Constraint-satisfying binary boson star initial data via XCFC

通过XCFC构建满足约束条件的二元玻色星初始数据

Gabriele Palloni, Nicolas Sanchis-Gual, José A. Font, Samuel Santos-Pérez, Isabel Cordero-Carrión, Pablo Cerdá-Durán, Claudio Lazarte

AI总结 本文提出了一种基于XCFC方法的构造满足约束条件的二元玻色星初始数据的方法,克服了传统方法中局部唯一性和收敛性问题,通过迭代求解器展示了该方法在多种标量场物质系统中的收敛性,包括高斯型轮廓、拓扑环形配置和等质量玻色星双星系统。

Comments 18 pages, 8 figures

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AI中文摘要

具有非平凡物质配置的数值相对论模拟需要满足爱因斯坦方程哈密顿和动量约束的初始数据。我们使用扩展共形平坦条件(XCFC)方法构造满足约束条件的标量场初始数据,其中物质变量被共形缩放,并引入了一个辅助矢量场。通过迭代求解器方法,我们展示了XCFC方法在几种标量场物质系统中的收敛性。这些包括高斯型轮廓、拓扑环形配置以及等质量玻色星双星系统。特别是对于后者,通常采用两个孤立玻色星解的叠加来构建初始数据。我们证明我们的方法通过生成真正的满足约束条件的初始数据,显著优于叠加方法。

英文摘要

Numerical-relativity simulations with non-trivial matter configurations require initial data that satisfy the Hamiltonian and momentum constraints of the Einstein equations. We construct constraint-satisfying scalar-field initial data using the eXtended Conformally Flat Condition (XCFC) formalism, in which the matter variables are conformally rescaled and an auxiliary vector field is introduced. In doing so, we overcome the issues of local uniqueness and convergence of the solutions that arise in the second-order elliptic equations associated with the constraints. Using an iterative solver method, we demonstrate the convergence of the XCFC approach to a solution for several scalar-field matter systems. Those include Gaussian-like profiles, topological torus configurations, and equal-mass boson star binaries. In particular, for the latter case, it is common to employ the superposition of two isolated boson star solutions in order to build the initial data. We show that our formalism significantly improves upon a superposition approach by generating genuinely constraint-satisfying initial data for boson star binaries.

2605.20887 2026-05-21 astro-ph.GA

Difference Between Half-mass Radius and Half-light Radius of Galaxies at 0.2 $< z <$ 2.5 Revealed by JWST/NIRCam Data

通过JWST/NIRCam数据揭示0.2 < z < 2.5红移范围内星系半光半质量半径之差

Mingen Xin, Guanwen Fang, Jie Song, Shiying Lu, Zesen Lin, Xu Kong

AI总结 研究利用JWST观测数据,测量了14333个恒星质量M* > 10^9 M_sun的星系的半光半质量半径,发现半光半质量半径之差与恒星质量及紫外-可见色有关,且星系演化中半质量半径比半光半径的增长趋势存在差异。

Comments 18 pages, 14 figures, 3 tables; published in The Astrophysical Journal

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AI中文摘要

利用JWST观测的CANDELS区域,我们测量了红移0.2 < z < 2.5范围内,恒星质量M* > 10^9 M_sun的14333个星系的半光半径(r_e,light)和半质量半径(r_e,mass)。为研究这两个半径的差异,我们发现对于静止星系(QGs)和恒星形成星系(SFGs),r_e,light均大于r_e,mass。此外,这两个半径的差异与星系的恒星质量、r_e,light以及视Rest-frame U-V色明显相关。当考察r_e,mass/r_e,light比值的演化时,我们发现SFGs在z > 1.7时有显著增加,而QGs在z > 1时没有明显增加,但在0.2 < z < 1.0时略有下降趋势。通过拟合银河系大小与恒星质量之间的线性关系,我们发现r_e,light的斜率比r_e,mass大约0.1到0.3个数量级。在固定恒星质量下,QGs的r_e,mass从z ~ 2.5到z ~ 0.2增加了约3到5倍,而SFGs的r_e,mass在相同红移范围内增加了约2倍,其增长趋势与r_e,light的增长趋势相近。这些结果表明,基于r_e,light的先前银河系演化见解在考虑r_e,mass时仍然有效,尽管具体斜率有所变化。

英文摘要

Using JWST observations in CANDELS fields, we measure the half-light radius ($r_{\rm e,light}$) and half-mass radius ($r_{\rm e,mass}$) for 14,333 galaxies with stellar masses $M_* > 10^9 M_\odot$ at redshifts $0.2 < z < 2.5$. To investigate the difference between $r_{\rm e,light}$ and $r_{\rm e,mass}$, we find that $r_{\rm e,light}$ is larger than $r_{\rm e,mass}$ for both quiescent galaxies (QGs) and star-forming galaxies (SFGs). Moreover, the difference between these two radii is clearly correlated with galaxy stellar mass, $r_{\rm e,light}$, and the rest-frame $U - V$ color. When examining the evolution of the $r_{\rm e,mass}/r_{\rm e,light}$ ratio, we observe a significant increase for SFGs at $z > 1.7$. In contrast, no clear increase is observed for QGs at $z > 1$, though a slight decreasing trend is seen between $0.2 < z < 1.0$. By fitting a linear relationship between galaxy size and stellar mass, we find that the slope for $r_{\rm e,light}$ is $\sim$ 0.1 to 0.3 dex larger than that for $r_{\rm e,mass}$. In terms of galaxy size evolution at a fixed stellar mass, the $r_{\rm e,mass}$ of QGs increases by a factor of $\sim$ 3 to 5 from $z \sim 2.5$ to $z \sim 0.2$. In contrast, the $r_{\rm e,mass}$ of SFGs increases by a factor of approximately 2 over the same redshift range, with this growth trend closely following that of their $r_{\rm e,light}$. These results indicate that previous insights into galaxy evolution based on $r_{\rm e,light}$ remain valid when considering $r_{\rm e,mass}$, although the specific slopes show some variations.

2605.20886 2026-05-21 astro-ph.GA

The TNG50-SKIRT Atlas: Multi-wavelength nonparametric galaxy morphology

TNG50-SKIRT图集:多波段非参数化星系形态

Sena Bokona Tulu, Maarten Baes, Angelos Nersesian, Tolu Biressa, Vicente Rodriguez-Gomez, Andrea Gebek, Marco Martorano, Abdissa Tassama Emana

AI总结 本文研究了不同波长对非参数化星系形态指标的影响,发现形态参数与恒星质量的相关性在不同波长下保持一致,但不同形态的星系在不同波长下的变化更显著,且尘埃吸收对形态指标的影响在整体上较小,但对个别星系可能显著。

Comments 13 pages, 8 figures, accepted for publication in A&A

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AI中文摘要

背景:星系形态是描述星系演化的一个基本属性。然而,特定星系的观测形态可能取决于观测的波长。目标:我们的目标是研究波长依赖性和尘埃吸收对非参数化形态指标的影响。方法:我们使用TNG50-SKIRT图集,这是为1154个完整恒星质量选定样本的星系提供的合成紫外到近红外(NIR)宽带图像图集,这些图像来自TNG50宇宙模拟在z=0时的模拟。对于每张图像,我们使用StatMorph代码计算四个非参数化形态指标。结果:我们发现,恒星质量与光学测量的形态参数之间的已知相关性,以及Gini-M20、浓度-Gini和浓度-M20平面中的相关性,与观测数据完全一致。然而,非参数化形态指标随着波长显著变化,且这种波长依赖性在盘状星系中比bulge主导的星系更显著。我们模拟的TNG50星系的形态波长依赖性与SINGS调查的本地星系测量结果一致。我们证明了尘埃吸收对非参数化形态指标的影响在整体星系人口中较小,但对个别星系可能显著。

英文摘要

Context: Galaxy morphology is a fundamental property to describe galaxy evolution. However, the observed morphology of a particular galaxy may depend on the observed wavelength. Aims: Our aim is to investigate the wavelength dependence and the effect of dust attenuation on nonparametric morphology indicators. Methods: We use the TNG50-SKIRT Atlas, an atlas of synthetic UV to near-infrared (NIR) broadband images for a complete stellar-mass-selected sample of 1154 galaxies extracted from the TNG50 cosmological simulation at $z = 0$. For each image, we calculate four nonparametric morphology indicators using the StatMorph code. Results: We find that the known correlations between the stellar mass and the morphological parameters measured in the optical, together with the Gini-$M_{20}$, concentration-Gini, and concentration-$M_{20}$ planes, are fully consistent with observational data. However, nonparametric morphological indicators change significantly with wavelength and that this wavelength dependence is stronger for disc-dominated than for bulge-dominated galaxies. The wavelength dependence of the morphology of our simulated TNG50 galaxies is consistent with measurements of local galaxies from the SINGS survey. We demonstrate that the effect of dust attenuation on nonparametric morphology indicators is modest across the full galaxy population but can be significant for individual galaxies.

2605.20884 2026-05-21 cs.MS cs.NA math.NA

Solving Multivariate Polynomial Systems and Rectangular Multiparameter Eigenvalue Problems with MacaulayLab

用MacaulayLab求解多元多项式系统和矩形多参数特征值问题

Christof Vermeersch, Bart De Moor

AI总结 本文介绍了MacaulayLab工具箱,该工具箱实现了求解多元多项式系统和矩形多参数特征值问题的数值线性代数算法,通过对比其他软件包如PNLA、PHCpack和MultiParEig,展示了其核心功能和性能。

Comments Since the manuscript is currently undergoing review, we anticipate several improvements in the upcoming revision. In particular, the comparison with other software packages will be expanded significantly

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AI中文摘要

我们介绍了Matlab工具箱MacaulayLab,该工具箱实现了求解多元多项式系统和矩形多参数特征值问题的数值线性代数算法。其结构和功能是多年研究和算法开发的结果。我们展示了该软件的工作方式,并将其性能与其他软件包如PNLA、PHCpack和MultiParEig进行比较。MacaulayLab的一些核心功能是它通过一种共同的方法解决两个关键问题,不依赖所选多项式基和单项式顺序,并能够处理无穷远处的正维解集。该工具箱(包括其未来更新)和大量测试问题都可在网上免费获取。

英文摘要

We present the Matlab toolbox MacaulayLab, which implements numerical linear algebra algorithms for solving multivariate polynomial systems and rectangular multiparameter eigenvalue problems. Its structure and functionality are the result of several years of research and algorithmic development. We demonstrate how the software works and compare its performance with other software packages, such as PNLA, PHCpack, and MultiParEig. Some core features of MacaulayLab are the fact that it solves two key problems via one common approach, works independently of the chosen polynomial basis and monomial order, and is capable of dealing with positive-dimensional solution sets at infinity. The toolbox (including its future updates) and a large collection of test problems are freely available online.

2605.20882 2026-05-21 cond-mat.soft

Monte Carlo simulation of selective adsorption in a binary hard-disk mixture on patterned adhesive surfaces

二元硬盘混合物在图案化粘性表面上选择性吸附的蒙特卡罗模拟

Nazar Kukarkin, Taras Patsahan

AI总结 本文通过大配分蒙特卡罗模拟研究了二元硬盘混合物在图案化粘性表面上的选吸附现象,探讨了表面几何对吸附选择性的影响,以及不同领域大小对吸附选择性的作用机制。

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AI中文摘要

利用大配分蒙特卡罗模拟研究了二元硬盘混合物在图案化粘性表面上的选吸附现象。两种物种具有相等的直径和相等的本体化学位,但对粘性域的吸引力不同。因此,由亲和力驱动的选择性与粒子大小不对称性和不等的化学位被分离。表面图案由域大小、域表面覆盖率以及圆形域的有序或无序排列定义。结果表明,选择性强烈依赖于表面几何,特别是在低和中等化学位时。与粒子大小相当的域通过形成具有大粒子-域重叠的吸附区域来增强选择性,而较大的域可以在低化学位时提供高选择性。对于小域,进一步减小尺寸也可以增加选择性,当系统接近均匀吸引表面时,相应物种的有效亲和参数也会相应变化。

英文摘要

Selective adsorption in a two-dimensional model of a binary hard-disk mixture on patterned adhesive surfaces is studied using grand canonical Monte Carlo simulations. The two species have equal diameters and equal bulk chemical potentials, but different attraction strengths to adhesive domains. Thus, affinity-driven selectivity is separated from particle-size asymmetry and unequal chemical potentials. The surface pattern is defined by domain size, domain surface coverage, and ordered or disordered arrangement of circular domains. The results show that selectivity depends strongly on surface geometry, especially at low and intermediate chemical potentials. Domains comparable to the particle size enhance selectivity by forming adsorption regions with large particle-domain overlap, whereas larger domains can provide high selectivity at low chemical potentials. For small domains, further reduction in size can also increase selectivity as the system approaches a uniform attractive surface with corresponding effective affinity parameters of the species.

2605.20880 2026-05-21 astro-ph.IM astro-ph.HE

Down going muon rate monitoring in the ANTARES detector

ANTARES探测器下行μ子率监测

K. Gracheva, M. Anghinolfi, V. Kulikovskiy, E. Shirokov, Y. Yakovenko

AI总结 本文提出了一种基于ANTARES探测器的下行μ子率监测方法,通过分析不同时间段的环境条件和探测器配置,对事件数据进行有效分组,以提高统计显著性。

Comments 8 pages, 7 figures, INFN/TC-11/05, June 26, 2011

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AI中文摘要

大型水下望远镜已被提出作为测量天体物理源高能中微子的一种具有挑战性的方法。近年来,ANTARES合作组在地中海海水中设计并实现了这种类型的首个探测器。通过探测器中光电倍增管(PMT)阵列测量的切连科夫光的到达时间和光子电子数,重构由中微子相互作用产生的μ子轨迹。为了获得足够的统计数据,必须将不同时间段的事件汇总在一起,同时考虑各种环境条件和探测器配置。在本文中,我们描述了基于每个运行中有效活跃PMT数量的有效标准,以对兼容的运行进行分组。

英文摘要

Large underwater telescopes have been proposed as a challenging method to measure high energy neutrinos from astrophysical objects. In recent years, The Antares collaboration has designed and realized the first detector of this type in the Mediterranean Sea. Muon tracks produced by the neutrino interaction in the surrounding medium are reconstructed from the arrival time and the number of photo-electrons of the Cherenkov light measured by the Photomultiplier tubes (PMT) array of the detector. In order to provide sufficient statistics, the events from various periods in the year must be summed together taking care of the various environmental conditions and detector configurations. In this note we describe effective criteria to group compatible runs based on the effective number of active PMTs in each run.

2605.20877 2026-05-21 math.CO

Navigating Posets with Few Maps

通过少量映射导航偏序集

Stefan Felsner, Jędrzej Hodor, Giacomo Ortali, Alexander Wolff

AI总结 本文研究了偏序集的两个新参数,旨在高效确定给定元素的后继集。通过定义平面映射和紧元素的概念,将mapability和atlas thickness与经典维度和宽度联系起来,并展示了计算这两个参数的复杂性。

Comments 12 pages

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AI中文摘要

我们研究了两个新的有限偏序集参数,这些参数源于高效确定给定元素后继集的问题。偏序集P=(X,≤)的平面映射是将X映射到二维平面R²的单射映射。给定平面上的两个不同点a和b,若a在坐标-wise上小于b,则称b支配a。我们说元素x在平面映射μ中是紧的,当且仅当x<y在P中当且仅当μ(y)支配μ(x)。注意,由定义可知,每个二维偏序集都允许一个映射,使得每个元素都是紧的。对于任何偏序集P,我们定义P的mapability,dmap(P),为单个映射中紧元素的最大数量;定义P的atlas厚度at(P),为使得每个元素至少在其中一个映射中是紧的的最小映射集合的大小。我们这些参数与经典概念维度和宽度相关:对于每个偏序集P,我们证明dim(P) ≤ 2at(P) ≤ width(P)+1。另一方面,存在一个偏序集序列(P_n)_{n≥1},其atlas厚度是其维度的双指数函数。在计算方面,我们证明对于给定的偏序集P,计算其mapability是NP难的,且决定at(P) ≤ 2也是NP难的。相比之下,我们证明计算偏序集的mapability在自然参数下是固定参数可计算的。

英文摘要

We study two new parameters for finite posets motivated by the problem of efficiently determining the set of successors of a given element. A plane map of a poset $P=(X,\leq)$ is an injective mapping of $X$ into the Cartesian plane $\mathbb{R}^2$. Given two different points $a$ and $b$ in the plane, we say that $b$ dominates $a$ if $a<b$ coordinatewise. We say that an element $x$ of $P$ is tight in a plane map $μ$ if the following holds: $x<y$ in $P$ if and only if $μ(y)$ dominates $μ(x)$. Note that, by definition, every 2-dimensional poset admits a map such that every element of the poset is tight. For any poset $P$, we define the mapability of $P$, $\mathrm{dmap}(P)$, to be the maximum number of elements that are tight in a single map, and we define the atlas thickness of $P$, $\mathrm{at}(P)$, to be the size of the smallest collection of maps such that every element is tight in at least one map of the collection. We relate these parameters to the classical notions of dimension and width: for every poset $P$, we show that $\mathrm{dim}(P) \le 2\mathrm{at}(P) \le \mathrm{width}(P)+1$. On the other hand, there exists a sequence of posets $(P_n)_{n \ge 1}$ such that the atlas thickness of $P_n$ is doubly exponential in the dimension of $P_n$. On the computational side, we prove that it is NP-complete, for a given poset $P$, to compute the mapability of $P$ and to decide whether $\mathrm{at}(P) \le 2$. In contrast to the latter, we show that computing the mapability of a poset is fixed-parameter tractable with respect to the natural parameter.

2605.20875 2026-05-21 math.OC

Spare Strategy for Large-Scale Satellite Constellations Under Dual Resupply Channels Using Markov Chain

基于马尔可夫链的双补给通道下大规模卫星编队的备用策略

Seungyeop Han, Shoji Yoshikawa, Takumi Noro, Takumi Suda, Koki Ho

AI总结 本文提出了一种基于马尔可夫链的方法,用于分析和设计大規模卫星编队的混合备用管理架构,通过建模卫星故障和补给过程为马尔可夫链,评估长期可行性,并通过遗传算法解决成本最小化问题。

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AI中文摘要

本文提出了一种基于马尔可夫链的方法,用于大規模卫星编队的早期阶段分析和混合备用管理架构的设计。该混合策略结合了两条通道:一条是通过重型发射将备用卫星停留在 parking 轨道,再转移至编队平面的间接路径;另一条是通过小型发射器直接将备用卫星送入平面轨道的直接路径。为了评估这些操作概念的长期可行性,卫星故障和补给过程被建模为马尔可夫链:间接通道遵循周期性审查的订货点/订货量政策,而直接通道使用标准的订货点/订货量政策。这些耦合的链通过固定点迭代在右升交点周期内产生周期性稳态,稳态分布提供了严格的成本和韧性指标。通过直接建模由轨道力学支配的随机、多层级动态,我们的框架避免了先前工作的聚合假设,并在更宽的操作域内保持有效。我们还引入了一种近似分析,保留延迟统计信息的同时显著减少模型规模。基于这种快速且准确的分析,我们提出了一个具有韧性的成本最小化问题,并使用遗传算法求解。该框架是通道中立的;优化过程会自主选择首选路径和角色。案例研究验证了分析结果与蒙特卡洛模拟的一致性,并展示了该框架在识别混合策略优于纯策略条件下的实际价值。

英文摘要

This paper presents a Markov-chain-based method for the early-phase analysis and design of hybrid spare-management architectures for large-scale satellite constellations.} The hybrid strategy combines two channels: an indirect path that stages spares in parking orbits via heavy launch for later transfer to constellation planes, and a direct path that delivers spares to in-plane orbits using small launch vehicles. {To assess the long-run viability of such concepts of operations, satellite failure and replenishment processes are modeled as a Markov chain:} the indirect channel follows a periodic-review reorder-point/order-quantity policy, while the direct channel uses a standard reorder-point/order-quantity policy. These coupled chains yield a periodic steady state over the right ascension of the ascending node cycle via fixed-point iteration, and the stationary distributions provide rigorous cost and resilience metrics. By directly modeling the stochastic, multi-echelon dynamics governed by orbital mechanics, our framework avoids the aggregation assumptions of prior works and remains valid across a wider operating domain. We also introduce an approximate analysis that preserves delay statistics while significantly reducing model size. Building on this fast, accurate analysis, we formulate a cost minimization problem with resilience constraints and solve it using a genetic algorithm. The framework is channel-neutral; the optimization autonomously selects the preferred path and roles. {A case study validates the analysis against Monte Carlo simulations and demonstrates the practical value of the framework in identifying the conditions under which the hybrid policy outperforms pure strategies.

2605.20871 2026-05-21 astro-ph.GA

Robustness Analysis of USmorph: II. Optimizing Feature Extraction, Dimensionality Reduction, and Clustering for Unsupervised Galaxy Morphology Classification

USmorph鲁棒性分析:II. 优化特征提取、降维和聚类以实现无监督星系形态分类

Guanwen Fang, Xiaolei Yin, Yirui Zheng, Zesen Lin, Shiwei Zhu, Jie Song, Chichun Zhou, Xu Kong

AI总结 本文研究了USmorph框架中无监督机器学习模块的鲁棒性,通过优化特征提取、降维和聚类方法,提升了星系形态分类的准确性和稳定性,验证了该方法在大规模天文调查中的可靠性。

Comments 16 pages, 9 figures, 2 tables; accepted for publication in The Astrophysical Journal

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AI中文摘要

我们对混合框架中的无监督机器学习模块进行了系统性的鲁棒性分析。该模块能够从大规模星系图像中自动发现形态结构,构成了完整的分类流程的基础。我们评估了五种预训练模型用于特征提取,并发现ImageNet预训练的AlexNet在捕捉判别性形态特征方面最为有效。由于其在保持高维结构和计算效率之间具有最佳平衡,UMAP被选作降维方法。为提高聚类稳定性,我们提出了一种基于Bagging的多聚类投票方案,显著提高了标签一致性和聚类纯度。我们比较了五种聚类算法的收敛性、可扩展性和质量,发现Bagging投票方案在结合K-means、Birch和Agg时表现最佳。使用Bagging聚类数K=16以达到分类粒度和人工验证效率的最佳平衡。我们的测试显示:(1) t-分布随机邻居嵌入(t-SNE)在低维空间中揭示了清晰、紧凑的聚类边界,具有强特征分离性;(2) 形态分类结果与星系演化理论一致,展示了参数空间中不同类型的物理合理分布。这些结果证明了USmorph的技术鲁棒性和科学可信度,使其成为未来如中国空间站望远镜(CSST)等大规模调查中自动化形态分类的可靠方法。

英文摘要

We conduct a systematic robustness analysis of the unsupervised machine learning module within the hybrid framework \texttt{USmorph}. This module automatically discovers morphological structures from large-scale galaxy images, forming the foundation of the complete classification workflow. We evaluate five pre-trained models for feature extraction and identify an ImageNet-pretrained AlexNet as the most effective for capturing discriminative morphological features. UMAP is chosen for dimensionality reduction due to its optimal balance between preserving high-dimensional structure and computational efficiency. To enhance clustering stability, we propose a Bagging-based multi-cluster voting scheme, which significantly improves label consistency and cluster purity. We compare the convergence, scalability, and quality of five clustering algorithms, finding that the Bagging voting scheme has the best performance with the combination of K-means, Birch, and Agg. A bagging clustering number of $K=16$ is used to achieve the optimal balance between classification granularity and manual validation efficiency. Our tests show that: (1) the t-distributed stochastic neighbor embedding (t-SNE) reveals clear, compact cluster boundaries in low-dimensional space with strong feature separability; (2) the morphology classification results align with galaxy evolution theory, showing physically plausible distributions of different types in parameter space. These results demonstrate the technical robustness and scientific credibility of \texttt{USmorph}, establishing it as a reliable method for automated morphological classification in future large-scale surveys such as the China Space Station Telescope (CSST) mission.

2605.20870 2026-05-21 physics.ins-det physics.class-ph

Development of a xenon triple point apparatus suitable for calibrating long-stem SPRTs and preliminary measurements of the temperature

开发一种氙气三相点装置,适用于校准长管标准铂电阻温度计及初步测量温度

Yikun Zhao, Jintao Zhang, Xiaojuan Feng, Yu Liang, Yongdong He, Hua Zhuo, Xiangrui Deng, Haibing Li

AI总结 本文提出了一种浸入式氙气三相点装置,用于校准长管标准铂电阻温度计和胶囊标准铂电阻温度计,并通过消除轴向热漏来提高测量精度,最终得到氙气三相点温度值,与之前的结果一致,差异在测量不确定度范围内。

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AI中文摘要

氙气具有高化学-物理稳定性和健康兼容性。氙气三相点(Xe TP)被认为是一个有前景的替代品,可以取代汞三相点(Hg TP)成为国际温标ITS-90定义固定点集的一部分。替代品的成功程度取决于Xe TP的实现水平,使用长管标准铂电阻温度计(LSPRTs)进行实现。本文报告了我们开发一种浸入式Xe TP装置的研究,该装置适用于校准LSPRTs和胶囊标准铂电阻温度计(CSPRT)。我们使用连续加热方法在装置上实现Xe TP的熔化平台。有效的熔化平台持续时间长达8-12小时,温度平坦度范围为0.37 mK-1.0 mK,在熔化分数从0.2到0.75之间。我们发现轴向热漏对Xe TP的测量有主要影响。我们通过改变Xe TP单元外壁的偏移温度来研究其影响。我们使用两个LSPRTs在修正轴向热漏后测量Xe TP。新的测量结果给出Xe TP为161.40571(55) K(k=1)在熔化分数F=1.0时,与之前通过绝热装置得到的结果一致,差异在0.11 mK到0.42 mK之间,这些差异被估计的测量不确定度所覆盖。

英文摘要

Xenon is of high chemical-physical stability and health compatibility. The xenon triple point (Xe TP) is accounted for a promising candidate replacing the mercury triple point (Hg TP) from the set of the defining fixed points of the international temperature scale ITS-90. The success of the alternative highly depends on the level of the realization of the Xe TP using long-stem standard platinum resistance thermometers (LSPRTs). We report in this article our study on the development of an immersion-type Xe TP apparatus, which is suitable for calibration of both LSPRTs and capsule standard platinum resistance thermometers (CSPRT). We realize the melting plateaus of the Xe TP using the continuous heating method on the apparatus. The effective melting plateaus extend for 8-12 hours long with temperature flatness range of 0.37 mK-1.0 mK over the melted fractions from 0.2 to 0.75. We find the axial heat leak contributing a principal effect influencing measurements of the Xe TP. We investigate the effect by varying the offset temperatures on the outer wall of the Xe TP cell. We measure the Xe TP using two LSPRTs upon correction of the axial heat leak. The new measurement, giving the Xe TP of 161.405 71 (55) K (k=1) at the melted fraction F=1.0, agrees well with those previously obtained by the adiabatic apparatuses. Their differences fall within 0.11 mK to 0.42 mK. by. Those differences are well covered by the estimated measurement uncertainty.

2605.20869 2026-05-21 cond-mat.mes-hall

The Topography Trap: Sifting Interlayer Excitons from Strain-Related Artifacts in Real-World 2D Hetrostructures

地形陷阱:在真实世界二维异质结构中区分异层激子与应变相关伪影

Pablo Hernández López, Luka Pirker, Astrid Weston, Arijit Kayal, Rafael Nadas, Adrián Dewambrechies Fernández, Álvaro Rodríguez, Roman Gorbachev, Kirill I. Bolotin, Otakar Frank, Sebastian Heeg

AI总结 该研究提出了一种决策树协议,通过层内激子淬灭评估异层耦合,并将光致发光与原子力显微镜相关联,以正确分配TMDC异质结构的室温PL特征。研究发现MoS2-MoSe2和MoS2-WSe2异质结构中存在MoMomentum-直接异层激子(KK-IX),而先前报告的明亮、动量间接、与扭角无关的ΓK-IX则被证明源于界面拓扑不均质处的局部应变。

Comments 21 pages, 3 figures

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AI中文摘要

在过渡金属二硫化物(TMDC)异质结构中出现的新激子现象是当前范德华材料物理中最激动人心的话题之一。异层激子(IXs)因其长辐射寿命和可通过电场、应变和扭角调节而突出。然而,在光学识别和操控IXs方面仍存在许多模糊之处,强调了需要可靠的光谱学标准来区分异层物种与伪信号。在此,我们提出了一种决策树协议,通过层内激子淬灭评估异层耦合,并将光致发光(PL)与原子力显微镜(AFM)相关联,以正确分配TMDC异质结构的室温PL特征。应用此协议,我们识别出在MoS2-MoSe2和MoS2-WSe2异质结构中在室温下存在MoMomentum-直接异层激子(KK-IX)。相比之下,我们的协议反驳了在MoS2-WSe2中报告的明亮、动量间接、与扭角无关的ΓK-IX。综合实验数据,包括红外和尖端增强光致发光(TEPL)具有亚衍射限制分辨率,显示没有令人信服的证据支持这种激子物种,尽管有大量报告。相反,此前被分配给这种ΓK-IX的光谱特征源于界面拓扑不均质处的局部应变,强调了在这一高度可访问领域中对真实样品进行稳健、空间分辨表征的必要性,并提供了一种可用于识别二维半导体异质结构中异层激子的一般适用框架。

英文摘要

Novel excitonic phenomena emerging in transition metal dichalcogenide (TMDC) heterostructures belong to the most exciting topics in contemporary physics of van der Waals materials. Interlayer excitons (IXs) stand out among those due to their long radiative lifetimes and tunability by electric fields, strain, and twist angle. However, many ambiguities persist in the optical identification and manipulation of IXs, highlighting the need for reliable spectroscopic criteria that distinguish interlayer species from spurious signals. Here, we present a decision-tree protocol that evaluates interlayer coupling via intralayer exciton quenching and correlates photoluminescence (PL) with atomic force microscopy (AFM) to correctly assign room-temperature PL features in TMDC-based heterostructures. Applying this protocol, we identify momentum-direct IX between the K valleys of the two layers (KK-IX) in MoS2-MoSe2 and MoS2-WSe2 heterostructures at room temperature. In contrast, our protocol contests the reported bright, momentum-indirect, twist-angle-independent $Γ$K-IX in MoS2-WSe2. Comprehensive experimental data, including infrared and tip-enhanced photoluminescence (TEPL) with sub-diffraction-limited resolution, show no compelling evidence for this excitonic species, despite numerous reports. Instead, the spectroscopic features previously assigned to this $Γ$K-IX originate from locally strained WSe2 at topographical inhomogeneities of the heterostructure interface, underscoring the need for robust, spatially resolved characterization of real-world samples in this highly accessible field and providing a generally applicable framework for identifying interlayer excitons in 2D semiconductor heterostructures.

2605.20864 2026-05-21 physics.optics

Scalable native signed optical computing enabled by dual-wavelength incoherent multiplexing

通过双波长非相干多路复用实现可扩展的原生带符号光计算

Yuan Ren, Yong Zheng, Ruixue Liu, Yunpeng Song, Qinfen Huang, Min Wang, Ya Cheng

AI总结 本文提出了一种基于双波长非相干多路复用的光子架构,实现了在薄 films 锂铌酸平台上的原生带符号输入和权重处理,通过共享物理路径进行计算,减少了硬件开销,并在神经网络分类任务中取得了高准确率。

Comments 13 pages, 4 figures

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AI中文摘要

非相干光子神经网络(PNNs)提供了一种稳健的模拟光学计算平台,但高效实现原生带符号操作仍然具有挑战性。现有的非相干 PNNs 方法通常需要额外的空间通道或时间编码步骤来表示双极输入信号,导致硬件开销随系统规模而增加。在此,我们展示了一种双波长非相干光子架构,该架构在薄 films 锂铌酸平台上原生支持带符号输入和权重。通过将互补的信号组件编码到两个波长通道,并在共享的物理路径内进行计算,所提出的方案消除了重复的加权单元。结果,与带符号计算相关的额外硬件开销保持恒定,与矩阵大小无关。所制造的设备具有超过 40 GHz 的调制带宽,并实现了四象限光学乘法,标准差误差为 1.27%。通过神经网络分类验证系统级功能,在 Moons 数据集上达到 95.1% 的准确率,在 MNIST 上达到 91.63%。这些结果确立了通往可扩展非相干光子计算系统的实用路径,具有原生双极处理能力。

英文摘要

Incoherent photonic neural networks (PNNs) provide a robust platform for analog optical computing, yet efficient implementation of native signed operations remains challenging. Existing incoherent PNNs approaches often require additional spatial channels or temporal encoding steps to represent bipolar input signals, resulting in hardware overhead that scales with system size. Here, we demonstrate a dual-wavelength incoherent photonic architecture that natively supports both signed inputs and signed weights on a thin-film lithium niobate platform. By encoding complementary signal components onto two wavelength channels and performing computation within a shared physical path, the proposed scheme eliminates duplicated weighting units. As a result, the additional hardware overhead associated with signed computation remains constant per multiply accumulate operation, independent of matrix size. The fabricated device exhibits a modulation bandwidth exceeding 40 GHz and achieves four-quadrant optical multiplication with a standard deviation error of 1.27%. System-level functionality is validated through neural-network classification, achieving 95.1% accuracy on the Moons dataset and 91.63% on MNIST. These results establish a practical route toward scalable incoherent photonic computing systems with native bipolar processing capability.

2605.20861 2026-05-21 astro-ph.SR astro-ph.IM

Adaptive multi-line fitting for stable line-core intensity and Doppler velocity

自适应多线拟合用于稳定线核强度和多普勒速度

Shahin Jafarzadeh, David B. Jess, Marco Stangalini, Peter H. Keys, Glen Chambers, Samuel D. T. Grant, Michele Berretti, Timothy J. Duckenfield

AI总结 本文提出LineFit方法,通过自适应多线拟合技术解决密集波长窗口中快速变化、不对称、混叠或多核核心的谱线核强度和多普勒速度时间序列的稳定性问题,同时展示了LineFit在处理复杂谱线时的鲁棒性和高效性。

Comments Accepted for publication in "Frontiers in Astronomy and Space Sciences": https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2026.1843842

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AI中文摘要

下一代太阳光谱仪越来越多地记录密集的波长窗口,在每个空间位置和时间步长中采样数十到数百条光谱线。这扩大了多线、多高度磁流体动力学运动诊断的范围,但也提出了实际挑战:当谱线轮廓快速变化、不对称、混叠或发展成多核核心时,推导稳定线核强度和视线速度时间序列。常见的快速估计器在处理简单、孤立的吸收线时表现良好,但在拥挤或形态复杂的案例中会间歇性错误识别核心。即使偶尔的跟踪错误也会导致台阶状伪影,重新分配功率并偏置用于波和动力学分析的谱、相位和相干度量。我们介绍了LineFit,一种完全可重复的自适应多线拟合方法,专为密集窗口光谱学设计。LineFit使用受限非线性最小二乘拟合本地建模每条线,包括一个不对称Voigt选项以适应不均的翼部展宽,并结合紧密配对所有权控制以及保守的、每线窗口适应和多核核心意识处理。使用一个具有明确真实值的合成时间序列,我们对LineFit与四个广泛使用的快速基线进行基准测试,并评估瞬时中心误差和下游时间序列诊断。几种快速方法在许多线中仍具竞争力,而LineFit在涉及间歇性多核核心轮廓的关键压力情况下最为稳健,并相应地产生与真实值最一致的功率谱。我们还展示了通过监督模拟加速LineFit软件的原理证明,提供至少三个数量级的处理时间改进。

英文摘要

Next-generation solar spectrographs increasingly record dense wavelength windows in which tens to hundreds of spectral lines are sampled at each spatial location and time step. This expands the scope for multi-line, multi-height diagnostics of magnetohydrodynamic motions, but also raises a practical challenge: deriving stable line-core intensity and line-of-sight velocity time series when profiles evolve rapidly, become asymmetric, blend, or develop multi-lobed cores. Common fast estimators can perform well for simple, isolated absorption lines, yet can intermittently misidentify the core in crowded or morphologically complex cases. Even infrequent mis-tracking can leave step-like artefacts that redistribute power and bias spectral, phase, and coherence measures used in wave and dynamics analyses. We introduce LineFit, a fully reproducible adaptive multi-line fitting approach tailored to dense-window spectroscopy. LineFit models each line locally with bounded non-linear least-squares fits to a Voigt-family profile, including an asymmetric-Voigt option to accommodate unequal wing broadening, and incorporates close-pair ownership control together with conservative, per-line window adaptation and split-core-aware handling. Using a synthetic time series with unambiguous ground truth, we benchmark LineFit against four widely used fast baselines and assess both instantaneous centre errors and downstream time-series diagnostics. Several fast methods remain competitive for many lines, whereas LineFit is most robust in key stress cases involving intermittently split-core profiles and correspondingly yields power spectra that agree most closely with the truth. We also demonstrate a proof-of-principle that benchmarks hybrid acceleration of the LineFit software via supervised emulation, offering at least three orders-of-magnitude improvement in processing time.

2605.20859 2026-05-21 hep-ph hep-ex

Impact of matter effects on the unitarity test of lepton mixing

物质效应对轻子混合矩阵单元性检验的影响

Ryuichiro Kitano, Joe Sato, Sho Sugama

AI总结 本文研究了在长基线中微子振荡实验中,考虑物质效应如何影响轻子混合矩阵单元性检验的方法,并探讨了如何利用未来实验测试混合矩阵的单元性,以发现超出标准模型的物理现象。

Comments 34 pages, 10 figures

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AI中文摘要

对轻子混合矩阵的单元性进行检验,类似于夸克领域CKM矩阵的单元性检验,是探索超出标准三重生成框架物理的重要步骤。在长基线中微子振荡实验中,振荡概率的公式可以写成包含不同混合矩阵元素组合的项之和,其系数对能量有不同的依赖关系。通过观测如T2HK和未来在J-PARC建设的中微子工厂的长基线实验的能谱信息,可以提取混合矩阵的元素,而无需假设特定的混合矩阵参数化。我们研究了如何将这种提取方法应用于中微子振荡,并考虑物质效应的影响,讨论如何在未来的长基线实验中测试混合矩阵的单元性。作为具体例子,我们利用四重生成模型进行单元性检验,考察一个在单元性模型中应趋于零的量。在可能的测量组合中,T2HK的CP共轭出现通道ν_μ→ν_e和ν̄_μ→ν̄_e的能谱,以及中微子工厂中可用的T共轭对ν_μ→ν_e和ν_e→ν_μ,提供了最强大的测试。

英文摘要

Testing the unitarity of the lepton mixing matrix, in a manner analogous to the unitarity tests of the CKM matrix in the quark sector, is an important step toward probing physics beyond the standard three-generation framework. In long baseline neutrino oscillation experiments, the formula of the oscillation probabilities can be written as a sum of terms with various combinations of the mixing-matrix elements, and their coefficients depend differently on energy. By observing the spectral information of long baseline experiments such as T2HK and a future neutrino factory at J-PARC with a $ν_e$ beam, the elements of the mixing matrix can be extracted without assuming a specific parametrization of the mixing matrix. We investigate how such an extraction method can be applied to neutrino oscillations by taking into account matter effects, and discuss how one can test unitarity of the mixing matrix in future long baseline experiments. As a concrete example, we examine the unitarity test by using a four-generation model, where we look at a quantity which should be vanishing in a unitary model. Among possible combinations of measurements, the most powerful test can be provided from the energy spectra of the CP-conjugate appearance channels $ν_μ\to ν_e$ and $\barν_μ\to \barν_e$ at T2HK, as well as from the T-conjugate pair $ν_μ\to ν_e$ and $ν_e \to ν_μ$ available at neutrino factories.

2605.20855 2026-05-21 physics.optics physics.app-ph

Local Circular Dichroism and Polarization Coupling in Phthalocyanine Molecular Assemblies Revealed by Photoinduced Force Microscopy

在类Phthalocyanine分子组装中局部圆二色性和极化耦合的揭示:通过光诱导力显微镜

Masayoshi Fujii, Mamoru Tamura, Hidemasa Yamane, Hajime Ishihara

AI总结 本文通过光诱导力显微镜研究了类Phthalocyanine分子组装中的局部圆二色性和极化耦合,利用离散偶极近似和非局部分子极化率进行理论分析,揭示了分子二聚体和四聚体在线性偏振和圆偏振光下的光学力谱和图像特征,展示了PiFM在分子组装中分辨集体极化模式和局部圆二色性响应的能力。

Comments 19 pages, 5 figures

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AI中文摘要

光诱导力显微镜(PiFM)通过直接检测光诱导力来实现光学响应的纳米级可视化,而无需依赖发光。在分子组装中,分子间极化耦合可以产生集体激发模式和缺失于孤立分子中的手性光学响应。在本研究中,我们利用离散偶极近似结合非局部分子极化率,理论地研究了ZnPc分子组装的PiFM图像。在线性偏振光照下,键合和反键合极化耦合模式在分子二聚体和四聚体的光学力谱和PiFM图像中产生特征空间分布。此外,在圆偏振光照下,分子间耦合和不对称分子排列生成了具有大不对称因子和空间变化的圆二色性分布。这些结果表明,PiFM能够分辨分子组装中的集体极化模式和局部手性光学响应,为纳米尺度的分子间光学相互作用提供了见解。

英文摘要

Photoinduced force microscopy (PiFM) enables nanoscale visualization of optical responses by directly detecting photoinduced forces without relying on luminescence. In molecular assemblies, intermolecular polarization coupling can generate collective excitation modes and chiral optical responses that are absent in isolated molecules. In this study, we theoretically investigate PiFM images of ZnPc molecular assemblies using the discrete dipole approximation combined with nonlocal molecular susceptibilities. Under linearly polarized illumination, bonding and antibonding polarization-coupling modes are found to produce characteristic spatial distributions in both the optical force spectra and PiFM images of molecular dimers and tetramers. Furthermore, under circularly polarized illumination, intermolecular coupling and asymmetric molecular packing generate enhanced local circular dichroism distributions characterized by large asymmetric factors and spatially varying chiral contrasts. These results demonstrate that PiFM can spatially resolve collective polarization modes and local chiral optical responses in molecular assemblies, providing insight into nanoscale intermolecular optical interactions.

2605.20852 2026-05-21 math.DG

On the Hamilton-Tian Conjecture in a compact transverse Fano Sasakian $5$-manifold

关于紧致横贯Fano萨克森5流形中的Hamilton-天猜想

Shu-Cheng Chang, Yingbo Han, Chien Lin, Chin-Tung Wu

AI总结 本文确认了在紧致横贯Fano准正则萨克森5流形中Sasaki-里奇流的Hamilton-天猜想,并推导了横贯Fano准正则萨克森5流形上Sasaki-里奇溶洞的紧致性定理,进一步通过第二萨克森结构定理确认了紧致横贯Fano萨克森5流形中的Hamilton-天猜想,并展示了梯度Sasaki-里奇溶洞轨道度量在紧致萨克森5流形上为Sasaki-爱因斯坦的条件。

Comments Combining some part of our previous paper arXiv:2210.12702

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AI中文摘要

在本文中,我们首先确认了在紧致横贯Fano准正则萨克森5流形中具有klt叶状结构奇点的Sasaki-里奇流的Hamilton-天猜想。其次,我们推导了横贯Fano准正则萨克森5流形上Sasaki-里奇溶洞的紧致性定理。然后,通过第二萨克森结构定理,我们确认了在紧致横贯Fano萨克森5流形中的Hamilton-天猜想。通过其应用,我们证明了在紧致萨克森5流形上梯度Sasaki-里奇溶洞轨道度量是Sasaki-爱因斯坦的条件是当M是横贯K-稳定的。

英文摘要

In this paper, we first confirm the Hamilton-Tian conjecture for the Sasaki-Ricci flow in a compact transverse Fano quasi-regular Sasakian $5$-manifold with klt foliation singularities. Secondly, we derive the compactness theorem of Sasaki-Ricci solitons on transverse Fano quasi-regular Sasakian $5$-manifolds. Then,by the second Sasakian structure theorem, we confirm the Hamilton-Tian conjecture for a compact transverse Fano Sasakian $5$-manifold. With its applications, we show that the gradient Sasaki-Ricci soliton orbifold metric on a compact Sasakian $5$-manifold is Sasaki-Einstein if $M$ is transverse $K$-stable.

2605.20851 2026-05-21 hep-th

Integrable sigma models with Haantjes structure on ${H_{4}}$ Lie group

可积σ模型与在H₄李代数上的Haantjes结构

Mirenayatollah Bahadori, Ali Eghbali, Adel Rezaei-Aghdam

AI总结 本文研究了H₄李代数上的Haantjes结构,通过求解代数关系和利用对应的自同构群,分类了所有不等价的代数Haantjes结构,并基于此结构变形了李群上的chiral σ模型,以保持其可积性,最终得到三个新的可积σ模型。

Comments 18 pages

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Journal ref
Nucl. Phys. B 1028 (2026) 117491
AI中文摘要

通过求解Haantjes结构在李代数G上的条件代数关系,并利用相应的自同构群,我们对G上的所有不等价的代数Haantjes结构进行了分类。在此过程中,我们获得了34个不等价的代数Haantjes结构。我们通过在李群上使用Haantjes结构来变形chiral σ模型,并尝试获得使变形后的σ模型保持可积性的条件。最后,利用H₄的Haantjes结构并解决这些条件,得到了三个新的H₄李群上的可积σ模型。

英文摘要

By solving algebraic relations for the conditions of Haantjes structure on a Lie algebra ${\G}$ and by using the corresponding automorphism group we proceed to classify all inequivalent algebraic Haantjes structures on ${\G}$. In this manner, we obtain 34 inequivalent algebraic Haantjes structures on the ${h_{4}}$ Lie algebra. We deform the chiral sigma model on a Lie group by using Haantjes structure on it. Then we try to obtain conditions on this structure such that the deformed sigma model remains to be integrable. Finally, using the ${h_{4}}$ Haantjes structures and solving this conditions three new integrable sigma models on the ${H_{4}}$ Lie group are obtained.

2605.20849 2026-05-21 math.OC

Large Language Models for Operations Research: A Comprehensive Survey

用于运筹学的大型语言模型:全面综述

Xianchao Xiu, Jianhao Li, Jun Fan, Wanquan Liu

AI总结 本文综述了大型语言模型在运筹学中的应用,探讨了其在模型构建、算法设计和解决方案验证中的作用,并总结了该领域的基准数据集和未来研究方向。

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AI中文摘要

运筹学(OR)作为复杂系统决策支持的核心方法,在数学、管理科学和计算机科学中具有重要应用。传统方法依赖专家知识,往往难以高效解决大规模和多约束问题。近年来,大型语言模型(LLMs)的快速发展为解决这些挑战提供了新的研究范式。本文系统地综述了用于运筹学的大型语言模型(LLM4OR)。我们首先介绍了OR问题的定义和LLMs的基本原理。然后分析了LLMs在OR中的作用,包括模型构建、算法设计和解决方案验证。此外,我们讨论了代表性场景中的实际应用,并总结了该领域的基准数据集。最后,我们概述了关键挑战,并提出了未来研究方向的视角。相关文献的集合可在https://github.com/xianchaoxiu/LLM4OR中找到。

英文摘要

Operations Research (OR) serves as a core decision-support methodology for complex systems, with significant applications across mathematics, management science, and computer science. Traditional approaches heavily rely on expert knowledge and often struggle to efficiently solve large-scale and multi-constraint problems. The rapid advancement of Large Language Models (LLMs) in recent years has offered a novel research paradigm to address these challenges. This paper presents a systematic survey of Large Language Models for Operations Research (LLM4OR). We begin by introducing the definition of OR problems and the fundamental principles of LLMs. We then focus on analyzing the roles of LLMs in OR, specifically covering such as model formulation, algorithm design, and solution verification. In addition, we discuss practical applications in representative scenarios and summarize benchmark datasets in this field. Finally, we outline the key challenges and provide perspectives on future research directions. A collection of related literature is available at https://github.com/xianchaoxiu/LLM4OR.

2605.20847 2026-05-21 cond-mat.soft cond-mat.dis-nn cond-mat.stat-mech

Unifying Plasticity in Ordered and Disordered Matter using Topological and Geometrical Descriptors

利用拓扑和几何描述符统一有序和无序物质中的塑性

Xin Wang, Yang Xu, Jin Shang, Yi Xing, Jie Zhang, Yujie Wang, Walter Kob, Matteo Baggioli

AI总结 本文通过引入位错、位形变和不兼容密度场,揭示了无序材料中塑性流动区域的识别问题,并展示了这些场在二维玻璃和三维颗粒系统中的预测能力,揭示了旋转缺陷在三维中的主导作用。

Comments v1: comments welcome

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AI中文摘要

识别无序固体中导致塑性流动的区域仍是一个开放性问题,因为结构无序似乎阻碍了位错、拓扑缺陷等概念在晶体系统中的直接应用。本文引入了位错、位形变和不兼容密度场,这些场可以还原为晶体中标准的塑性源,并评估其在无序材料中的预测能力。我们发现,在模拟的二维玻璃以及二维和三维的实验颗粒系统中,这些场与$D^2_{ ext{min}}$表现出强烈的空间相关性,$D^2_{ ext{min}}$是用于定位无序固体中剪切下的塑性事件的标准度量。与$D^2_{ ext{min}}$不同,这些场还能区分旋转和翻译对塑性事件的贡献,揭示在三维中旋转缺陷变得主导。我们的方法为晶体和无序固体中塑性的统一描述铺平了道路。

英文摘要

Identifying the regions responsible for plastic flow in amorphous solids remains an open problem, since structural disorder seems to prevent the direct application of concepts such as dislocations, topological defects that successfully describe irreversible deformations in crystalline systems. Here, we introduce fields of dislocation, disclination, and incompatibility densities, that reduce to the standard sources of plasticity in crystals and assess their predictive power in amorphous materials. We find that, in a simulated two-dimensional glass as well in two- and three-dimensional experimental granular systems, these fields exhibit strong spatial correlations with $D^2_{\text{min}}$, the standard measure used to locate plastic events under shear in disordered solids. Unlike $D^2_{\text{min}}$, these fields also allow to disentangle rotational and translational contributions to the plastic events, revealing that rotational defects becoming dominant in three dimensions. Our approach paves the way for a unified description of plasticity in crystalline and amorphous solids.

2605.20846 2026-05-21 math.AT math-ph math.GT math.MP math.QA

Topological Field Theories and the Algebraic Structures of the Two-Sphere

拓扑场论与二维球面的代数结构

Chris Li

AI总结 本文研究了三维定向 bordism 分类 $\operatorname{Cob}(3)$ 中 $S^2$ 的 bordisms,通过拓扑场论定义了 P-monoids 和 L-monoids,这两种 monoids 都是交换 Frobenius monoids,并分别带有端射影和单位射影,这些结构与闭定向不可约 3-流形标记。通过 legs 关系,这些新的素结构与交换 Frobenius 结构有可数关系,并通过限制到代数中,发现这些素结构被强约束,最终简化为素单位的乘法。此外,本文还提出了一个 $\infty$-operad 来编码这些素结构,并包含 $\infty$-little 3-cube operad 作为子 operad。

Comments 99 pages

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AI中文摘要

我们为 $S^2$ 在三维定向 bordism 分类 $\operatorname{Cob}(3)$ 中的 bordisms 提供了两种表示,编码了 $S^2$ 上的代数结构。通过拓扑场论,我们定义了两种 monoids,称为 P-monoids 和 L-monoids。除了都是交换 Frobenius monoids 之外,P-monoids 配备了一类端射影,而 L-monoids 配备了一类单位射影,所有这些结构都由闭定向不可约 3-流形标记。它们被证明是等价的。新的素结构满足与交换 Frobenius 结构的一些可数关系,其中最显著的是所谓的“腿关系”。然后我们限制到代数的设定中,发现腿关系对新的素端射影施加了强约束,迫使它们通过素单位的乘法作用,使得额外的素结构变得非常简单。我们还提出一个 $\infty$-operad 来编码这些素结构,并包含 $\infty$-little 3-cube operad 作为子 operad。我们还简要讨论了 P/L-代数与 J-代数之间的关系,后者分类了三维 TFTs。

英文摘要

We give two presentations for bordisms of $S^2$ in the 3-dimensional oriented bordism category $\operatorname{Cob}(3) $, encoding the algebraic structures on $S^2$. After passing through topological field theories, we define two kinds of monoids which we call P-monoids and L-monoids. In addition to both being commutative Frobenius monoids, P-monoids are equipped with a class of endomorphisms while L-monoids are equipped with a class of unit morphisms, all of which are labelled by closed oriented irreducible prime 3-manifolds. They turn out to be equivalent. The new prime structures satisfy some countable relations with the commutative Frobenius structure, the most notable of which we call "legs relations." We then restrict to the setting of algebras and show that the legs relations place strong constraints on the new prime endomorphisms which forces them to act by multiplications by prime units, rendering the additional prime structures remarkably simple. We also propose an $\infty$-operad which encodes these prime structures and contains the $\infty$-little 3-cube operad as a sub-operad.% We briefly discuss the relations between P/L-algebras and J-algebras which classify 3-dimensional TFTs.

2605.20845 2026-05-21 math.AP

Local well-posedness for the two-and-a-half-dimensional EMHD system with split fractional dissipation

二维半电子磁流体动力学系统(EMHD)在分裂分数耗散下的局部适定性

Qirui Peng

AI总结 本文研究了具有分量分数耗散的二维半电子磁流体动力学(EMHD)系统,证明了在初始数据满足一定正则性条件时,系统在分数耗散参数满足α+β>2的情况下具有局部适定性,通过Littlewood-Paley能量估计、交换子界和低-高相互作用的抵消来控制Hall非线性项。

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AI中文摘要

我们研究了在二维流形$\mathbb T^2$上具有分量分数耗散的二维半电子磁流体动力学(EMHD)系统:$\partial_t a+a_yb_x-a_xb_y=-Λ^αa$和$\partial_t b-a_yΔa_x+a_xΔa_y=-Λ^βb$,其中$0<α,β<2$。该系统是Hall-MHD/EMHD中磁场方程在假设$B= abla imes(ae_z)+be_z$下的二维半约简。我们证明,对于初始数据$(a_0,b_0)\in H^{s+1}(\mathbb T^2) imes H^s(\mathbb T^2)$,其中$s\geq 2-\varepsilon$,当且仅当$α+β>2$时,系统具有局部适定性。因此,每个分量不需要携带完整的拉普拉斯耗散;两个分数耗散的平滑效应可以结合以控制Hall非线性项。证明基于Littlewood-Paley能量估计、交换子界以及低-高相互作用之间的抵消。

英文摘要

We study the $2\frac12$-dimensional electron magnetohydrodynamics (EMHD) system on $\mathbb T^2$ with componentwise fractional dissipation: $\partial_t a+a_yb_x-a_xb_y=-Λ^αa$ and $\partial_t b-a_yΔa_x+a_xΔa_y=-Λ^βb$, where $0<α,β<2$. This system is a $2\frac12$-dimensional reduction of the magnetic equation in Hall--MHD/EMHD under the ansatz $B=\nabla\times(ae_z)+be_z$. We prove local well-posedness for initial data $(a_0,b_0)\in H^{s+1}(\mathbb T^2)\times H^s(\mathbb T^2)$ with $s\geq 2-\varepsilon$, provided that $α+β>2$. Thus neither component is required to carry a full Laplacian dissipation; the smoothing effects of the two fractional dissipations can be combined to control the Hall nonlinearity. The proof is based on Littlewood--Paley energy estimates, commutator bounds, and cancellations between the leading low--high interactions.

2605.20844 2026-05-21 math.QA math.GT

Brunnian braids and the inclusion from double shuffle Lie algebra to Kashiwara-Vergne Lie algebra

Brunnian braids和从双重shuffle李代数到Kashiwara-Vergne李代数的包含

Muze Ren

AI总结 本文证明了Brunnian braids的双重shuffle李代数通过infinitesimal hexagon方程注入到对称Kashiwara-Vergne李代数,并扩展了这一包含到两个方向:利用Brunnian Lie代数的下正则系列以及建立pentagon方程映射、stuffle coproduct、divergence映射和necklace cobracket之间的显式联系。

Comments 24 pages, comments are welcome

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AI中文摘要

L.Schneps证明了双重shuffle李代数$\mathfrak{dmr}_0$注入到Kashiwara-Vergne李代数$\mathfrak{krv}_2$。本文展示$\mathfrak{dmr}_0$通过infinitesimal hexagon方程注入到对称Kashiwara-Vergne李代数$\mathfrak{krv}^{\mathrm{sym}}_2$。证明基于Brunnian braids群在不同 genus 0 表面的包含,不同于Schneps在\cite{Schneps2012,Schneps2025}中使用mould calculus的方法。我们从两个方向扩展了这一包含:一个使用Brunnian Lie代数的下正则系列,另一个是建立pentagon方程映射、stuffle coproduct、divergence映射和necklace cobracket之间的显式联系。

英文摘要

It is proved by L.~Schneps that the double shuffle Lie algebra $\mathfrak{dmr}_0$ injects to the Kashiwara-Vergne Lie algebra $\mathfrak{krv}_2$ in \cite{Schneps2012,Schneps2025}. We show that $\mathfrak{dmr}_0$ with the infinitesimal hexagon equation $[x,φ(-x,-y,x)]+[y,φ(-x-y,y)]=0$ injects to the symmetric Kashiwara-Vergne Lie algebra $\mathfrak{krv}^{\mathrm{sym}}_2$. The proof is based on the inclusion of brunnian braids group on different genus 0 surfaces which is different from the method of mould calculus in \cite{Schneps2012,Schneps2025}. We generalize the inclusion in two directions, one using lower central series of brunnian Lie algebras and the other is to establish explicit links between the pentagon equation map, the stuffle coproduct, the divergence map and the necklace cobracket.

2605.20843 2026-05-21 astro-ph.HE astro-ph.GA

Characterizing the origins of gamma-ray variability of the jetted active galactic nuclei observed with the Fermi-LAT

刻画由费米-拉特观测的喷流活动星系核γ射线变化的起源

Yongyun Chen, Qiusheng Gu, Junhui Fan, Dingrong Xiong, Xiaoling Yu, Xiaogu Zhong, Xiaotong Guo, Nan Ding

AI总结 本文通过利用存档费米-拉特光变曲线并应用阻尼随机游走模型,分析了大量喷流活动星系核的γ射线变化,发现γ射线发射区域可能位于BLR之外,与尘埃环有关,并揭示了γ射线变化与射流活动之间的潜在关系。

Comments 19 pages, 7 figures, accept for publication in the Astrophysical Journal Supplement

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AI中文摘要

我们通过利用存档费米-拉特光变曲线并应用阻尼随机游走模型,对大量喷流活动星系核的γ射线变化进行了分析。我们的主要发现如下:(1)我们源的平均变化阻尼时间尺度约为100天。这可能表明扩散激波加速在γ射线发射的变化中起重要作用。(2)平坦谱射电耀斑体(FSRQs)的变异性幅度大于BL Lacertae对象(BL Lacs)。(3)我们源的发射区域到中央超大质量黑洞的距离与尘埃环半径的比值约为R≈2-4.5R_DT。相比之下,我们源的发射区域到中央超大质量黑洞的距离与BLR半径的比值为R≈135-295R_BLR-in和R≈123-270R_BLR-out。这些发现表明,喷流AGNs的γ射线发射区域可能位于BLR之外,可能与尘埃环有关。(4)变异性幅度与射电亮度、射电 Loudness、X射线亮度、X射线 Loudness、γ射线亮度和γ射线 Loudness之间存在统计相关性,表明γ射线变化与喷流活动之间可能存在潜在关系。(5)变异性幅度也与同步加速峰值频率亮度、逆康普顿峰值频率亮度和康普顿主导度之间存在统计相关性。(6)变异性幅度也与黑洞质量、吸积盘亮度和爱丁顿比相关,表明吸积盘可能也对γ射线变化有所贡献。

英文摘要

We conducted an analysis of gamma-ray variability in a large sample of jetted active galactic nuclei (AGNs) by utilizing archival Fermi-LAT light curves and applying damped random walk modeling to obtain variability amplitude. Our primary findings are summarized as follows: (1) The mean variability damping timescales of our sources are approximately 100 days. This damping timescale may imply that the diffusive shock acceleration plays an important role in the variability of gamma-ray emission. (2) Flat-spectrum radio quasars (FSRQs) demonstrate greater variability amplitude compared to BL Lacertae objects (BL Lacs). (3) The ratio of the distance of the emission region from the central supermassive black hole to the dusty torus radius for our sources is $R\approx2-4.5R_{\rm DT}$. In contrast, the ratio of the distance of the emission region from the central supermassive black hole to the BLR radius for our sources is $R\approx135-295R_{\rm BLR-in}$ and $R\approx123-270R_{\rm BLR-out}$. These findings indicate that the $γ$-ray emission region in jetted AGNs is likely located beyond the BLR, potentially could be associated with the dusty torus. (4) A statistical correlation is observed between variability amplitude and radio luminosity, radio loudness, X-ray luminosity, X-ray loudness, gamma-ray luminosity, and gamma-ray loudness, indicating a potential relationship between gamma-ray variability and jet activity. (5) Variability amplitude also shows a statistical correlations with synchrotron peak frequency luminosity, inverse Compton peak frequency luminosity, and Compton dominance. (6) Variability amplitude also correlates with black hole mass, accretion disk luminosity, and Eddington ratio, implying that the accretion disk may also contribute to gamma-ray variability.

2605.20842 2026-05-21 math.NA cs.NA

Efficient and simple fourth-order compact finite difference methods for convection-diffusion-reaction equations on arbitrary curved domains

高效且简单的四阶紧致有限差分方法用于任意曲域上的对流-扩散-反应方程

Qiwei Feng, Bin Han, Peter Minev

AI总结 本文提出了一种高效的四阶紧致有限差分方法,用于求解具有变量光滑系数的二维对流-扩散-反应方程及其在复杂、细长和曲域上的Dirichlet边界条件,该方法在任意不规则 stencil 中保持了简单且高阶的精度。

Comments 26 pages, 19 figures, and 7 tables

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AI中文摘要

在本文中,我们讨论了具有变量光滑系数的二维对流-扩散-反应方程及其在复杂、细长和曲域上的Dirichlet边界条件。我们提出了一种在每个网格点上使用均匀笛卡尔网格的四阶紧致有限差分方法(FDM)。对于常规的stencil中心,我们利用四阶紧致9点FDM来近似解。根据初步分析,我们利用垂直和水平变换推导出10种情况下的四阶紧致FDM,适用于所有不规则stencil中心。为了获得每个情况下的四阶FDM的左端stencil,我们只需要求解一个最多6×24的线性系统,该系统以显式公式呈现。FDM的右端部分对于任何不规则stencil中心也以显式表达式构建。为了实现四阶一致性,常规stencil中心的FDM使用了对流、扩散、反应和源项的二阶偏导数,而不规则stencil中心的FDM仅需使用对流、扩散、反应和源项的一阶偏导数,以及Dirichlet边界函数和边界曲线参数表达式的三阶导数。我们测试了具有100片叶、高曲率、高频率、急剧变化和几乎重叠的边界曲线的挑战性域,所提出的FDM在l2和l∞范数下产生了高精度和稳定的四阶收敛率。所有我们的FDM的stencil都具有简单期望的结构,仅通过在标准紧致9点stencil中保留域Ω内的网格点,即可在常规stencil和边界stencil中实现,而无需假设任何域外的信息。

英文摘要

In this paper, we discuss the 2D convection-diffusion-reaction equation with variable smooth coefficients and the Dirichlet boundary condition on a complicated, thin, and curved domain. We propose the fourth-order compact FDM at every grid point with the uniform Cartesian mesh. For the regular stencil center, we utilize the fourth-order compact 9-point FDM to approximate the solution. According to the preliminary analysis, we use vertical and horizontal transformations to derive fourth-order compact FDMs in 10 cases for all irregular stencil centers. To obtain the left-hand side of the stencil of the fourth-order FDM in each case, we only need to solve an at most $6 \times 24$ linear system which is presented with the explicit formula. The right-hand side of the FDM is constructed in explicit expression for any irregular stencil centers too. To achieve the fourth-order consistency, up to second-order partial derivatives of convection, diffusion, reaction, and source terms are used for the FDM at the regular stencil center, and the FDM at an irregular stencil center only requires first-order partial derivatives of convection, diffusion, reaction, and source terms, and up to third-order derivatives of the Dirichlet boundary function and the parametric expression of the boundary curve. We test challenging domains with 100-leaf, high-curvature, high-frequency, sharply varying, and nearly overlapping boundary curves, the proposed FDM produces the high accuracy and the stable fourth-order convergence rate in $l_2$ and $l_{\infty}$ norms. All stencils of our FDMs have a simple desired structure by only keeping grid points inside $Ω$ in the standard compact 9-point stencil for both regular stencils and boundary stencils, but without assuming any information outside the domain $Ω$.

2605.20841 2026-05-21 math.LO

Intuitionism and computing with partial information

直觉主义与部分信息计算

Hristo Ganchev, Paul Shafer, Theodore A. Slaman, Andrea Sorbi, Mariya I. Soskova

AI总结 本文研究了直觉主义命题演算在部分信息下的建模,通过构造分裂类枚举度来证明Dyment-Muchnik晶格的初始段能生成Brouwer代数,而完整的Dyment和Dyment-Muchnik晶格则包含弱排除中律。

Comments 27 pages

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AI中文摘要

存在Dyment晶格和Dyment-Muchnik晶格的初始段,能够生成恰好建模直觉命题演算的Brouwer代数。对于Dyment-Muchnik晶格,这一结果是通过构造枚举度的分裂类来获得的。相比之下,完整的Dyment晶格和完整的Dyment-Muchnik晶格则建模了直觉命题演算加上弱排除中律。我们还观察到某些自然可定义的枚举度类,在向下闭合于枚举可约度下,无法形成分裂类。

英文摘要

There exist initial segments of both the Dyment lattice and the Dyment-Muchnik lattice that yield Brouwer algebras modeling exactly the intuitionistic propositional calculus. For the Dyment-Muchnik lattice, this result is obtained by constructing a splitting class of enumeration degrees. In contrast, the full Dyment lattice and the full Dyment-Muchnik lattice model the intuitionistic propositional calculus plus the weak law of excluded middle. We also observe that certain naturally definable classes of enumeration degrees, which are downwards closed under enumeration reducibility, fail to form splitting classes.

2605.20840 2026-05-21 math.MG

A positive solution to the $L^p$ projection centroid conjecture

$L^p$投影质心猜想的一个正解

Jin Dai, Tuo Wang

AI总结 本文研究解决了$L^p$投影质心猜想,通过提出新的方法和理论证明了该猜想的正确性。

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AI中文摘要

在2000年的经典论文[20]中,Lutwak-Yang-Zhang建立了$L^p$类的Petty投影不等式和Busemann-Petty质心不等式的$L^p$类。在[20]的第7节中,Lutwak-Yang-Zhang提出了重要的$L^p$投影质心猜想。本文在该项工作中给出了该猜想的正解。

英文摘要

In a classical paper [20] in 2000, Lutwak-Yang-Zhang established the $L^p$ analog of the Petty projection inequality and the $L^p$ analog of the Busemann-Petty centroid inequality. In Section 7 of [20], Lutwak-Yang-Zhang proposed the important $L^p$ projection centroid conjecture. We give a positive solution to the $L^p$ projection centroid conjecture in this work.

2605.20836 2026-05-21 physics.optics

Towards compact high-frequency nonreciprocal devices using nanoplasma-switched time-varying metasurfaces

基于纳米等离子开关的高频率非互易器件的紧凑设计

Mikhail Sidorenko, Jin Zhang, Xuchen Wang, Zhipei Sun, Sergei Tretyakov, Viktar Asadchy

AI总结 本文提出了一种基于时间调制元件的非互易时间调制器件设计方法,利用纳米等离子开关实现高频操作,并通过实例展示了100GHz微波隔离器的设计与仿真。

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AI中文摘要

时间调制系统近年来受到越来越多的关注。它们允许我们定制各种效应,如频率转换、单向传播等。对于微波波段,通常使用半导体元件,如变容二极管,作为时间调制元件,但其调制频率通常被限制在几吉赫兹范围内。最近在纳米等离子开关方面的进展,即基于纳米尺度间隙中气体放电的双态电子开关,为开发具有高操作频率的时间调制系统提供了新的潜力。本文开发了一种基于时间-傅里叶方法的分析框架,用于设计基于双态时间调制元件的非互易时间调制器件,例如基于纳米等离子的开关。开发了一个实际的微波隔离器示例,其工作频率为100GHz,并通过分析和全波仿真进行了研究。此外,还模拟了在平行板波导中的潜在实现。

英文摘要

Time-modulated systems have received growing interest in recent years. They allow us to tailor effects, such as frequency conversion, single-direction propagation, etc. For the microwave band, semiconductor elements, such as varactors, are usually used as time-modulated elements but their modulation frequency has been limited to the few-gigahertz range. Recent advances in nanoplasma switches, i.e., two-state electronic switches based on a gas discharge in a nanometer-scale gap, provide a new potential for developing time-modulated systems with high operating frequencies. Here, we develop an analytical framework based on the time-Floquet method for the design of nonreciprocal time-modulated devices based on two-state time-modulated elements, for instance, nanoplasma-based switches. A practical example of a microwave isolator operating at 100~GHz frequency is developed and studied both analytically and using full-wave simulations. A potential realization in a parallel-plate waveguide is also simulated numerically.

2605.20835 2026-05-21 astro-ph.GA

Evolution of compressed clouds formed by filament coalescence. I. Oblique collisions

由丝状物凝聚形成的压缩云的演化。I. 偏斜碰撞

Raiga Kashiwagi, Kazunari Iwasaki, Kohji Tomisaka, Tsuyoshi Inoue

AI总结 研究通过三维理想磁流体力学模拟,探讨了两个磁化丝状物偏斜碰撞的基本演化过程,揭示了碰撞角度、速度和初始线质量对压缩云引力坍缩的影响,并确定了促进恒星形成的关键碰撞条件。

Comments 14 pages, 8 figures, Accepted to Publications of the Astronomical Society of Japan (PASJ)

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AI中文摘要

恒星被认为主要在丝状分子云中形成。最近的研究表明,包括恒星团和大质量恒星形成的活跃恒星形成发生在所谓的“枢纽”结构中,即多个丝状物汇聚处。因此,理解此类枢纽-丝状物系统的形成和演化对于揭示恒星团和大质量恒星形成的物理过程至关重要,尽管完整图景仍不完整。为此,我们聚焦于丝状物-丝状物碰撞作为枢纽形成的一种潜在机制。在本研究中,我们利用三维理想磁流体力学模拟,研究了两个磁化丝状物之间偏斜碰撞的基本演化过程。作为初始丝状物的模型,我们考虑了两个相同的有限长度磁化丝状物,改变其长轴之间的碰撞角度、速度(设定为垂直于长轴)和初始线质量。我们发现,当碰撞角度从正交减小到平行时,压缩云更易发生引力坍缩。此外,碰撞后压缩云的不稳定性可通过其能量平衡来解释。具体而言,如果碰撞后立即的绝对引力能超过动能、热能和磁能之和,云将发生引力坍缩。反之,如果引力能较小,云将膨胀。此外,我们还估计了促成枢纽-丝状物形成的碰撞速度上限,并确定了有利于大质量恒星形成的碰撞条件。

英文摘要

Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures, where multiple filaments converge. Understanding the formation and evolution of such hub-filament systems is therefore essential for unveiling the physical processes responsible for cluster and massive star formation, although the full picture remains incomplete. To address this, we have focused on filament-filament collisions as a potential formation mechanism of the hubs. In this study, we investigate the fundamental evolutionary processes of oblique collisions between two magnetized filaments using three-dimensional ideal magnetohydrodynamical simulations. As a model of initial filaments, we consider two identical finite-length magnetized filaments, varying the collision angle between their long axes, the collision velocity, which is set perpendicular to the long axes, and the initial line mass. We find that as the collision angle decreases from orthogonal to parallel, the compressed cloud becomes more prone to gravitational collapse. In addition, the instability of the post-collision compressed cloud can be explained by its energy balance. Specifically, if the absolute value of the gravitational energy exceeds the sum of the kinetic, thermal, and magnetic energies immediately after the collision, the cloud undergoes gravitational collapse. Conversely, if the gravitational energy is smaller, the cloud expands. In addition, we estimate the upper limit of the collision velocity that enables hub-filament formation and identify the collision conditions favorable for massive star formation.