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2606.08619 2026-06-09 physics.chem-ph physics.comp-ph 新提交

On the Covalent Fields of Molecule-Surface Interactions

关于分子-表面相互作用的共价场

Edvin Fako, Philippe Schwaller

AI总结 提出共价场理论(CFT),将化学亲和性表示为界面连续属性,解决活性位点歧义、BEP关系经验性和线性比例关系不可预测性问题,并在高熵合金和氧化物上验证。

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AI中文摘要

活性位点的歧义性、Brønsted-Evans-Polanyi关系的经验性以及线性比例关系崩溃的不可预测性,是单一表示选择(将化学亲和性视为离散几何位点的属性)的三个症状。我们在此表明,当化学亲和性被表示为界面的连续属性——共价场时,这三个问题都得到解决。我们提出了一个框架——共价场理论(CFT),其中活性位点作为场维持超过热阈值的成键偏好的区域出现,消除了几何分类的需要。线性比例关系是跨探针家族的场中的相关结构;它们的崩溃是具有精确几何特征的拓扑分岔。Brønsted-Evans-Polanyi相关性源于共价场分解,为先前被视为经验规律的现象提供了理论基础,并在约120,000条候选路径上得到验证。应用于高熵合金纳米颗粒和部分还原的高熵氧化物,CFT将这些性质映射到任意组成和结构复杂性的表面上。

英文摘要

The ambiguity of the active site, the empirical status of Brønsted-Evans-Polanyi relations, and the unpredictability of linear scaling relation breakdown are three symptoms of a single representational choice: treating chemical affinity as an attribute of discrete geometric sites. Here we show that all three are resolved when chemical affinity is represented as a continuous property of the interface: the covalent field. We present a framework, Covalent Field Theory (CFT), in which active sites emerge as regions where the field sustains a bias toward bond formation beyond the thermal threshold, removing the need for geometric classification. Linear scaling relations are correlation structure in the field across probe families; their breakdown is a topological bifurcation with a precise geometric signature. Brønsted-Evans-Polanyi correlations arise from the covalent field decomposition, providing a theoretical basis for what has previously been treated as an empirical regularity, demonstrated across ~120,000 candidate pathways. Applied to a high-entropy alloy nanoparticle and a partially reduced high-entropy oxide, CFT maps these properties onto surfaces of arbitrary compositional and structural complexity.

2606.08618 2026-06-09 physics.med-ph cs.SY eess.SY 新提交

Coil-Integrated Alignment Sensor for Real-Time Feedback of Coil-Scalp Contact Point and Angle During Transcranial Magnetic Stimulation (TMS)

线圈集成对准传感器用于经颅磁刺激(TMS)中线圈-头皮接触点与角度的实时反馈

B. Seyed, M. Koehler, S. M. Goetz

AI总结 针对TMS中线圈与头皮对准问题,提出一种基于消费电子组件的低成本传感器,实时监测接触点位置和压力,提供反馈,且对TMS脉冲具有鲁棒性。

Comments 7 pages, 1 figure

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AI中文摘要

尽管经颅磁刺激(TMS)中使用现代聚焦刺激线圈到达特定皮层目标的线圈定位已被深入研究,但线圈与头部的对准和接触常常被忽略。聚焦八字形线圈表面有一个点,在该点产生最大的感应电场。这个点应首先接触头部,且线圈在该点应大致与头部相切。先前的研究表明,如果线圈未以正确的点接触头部,会产生巨大影响,并且许多操作员难以建立或维持正确的线圈-头皮对准。本文提出一种技术支持技术,可以监测接触点的精确位置以及压力,从而向用户提供反馈。由于该系统完全使用消费电子组件,传感器成本低廉。通过适当设计,我们实现了足够的鲁棒性,使得传感器在TMS脉冲期间不会重置,也不会显示出任何可检测的性能退化。

英文摘要

Whereas coil positioning in transcranial magnetic stimulation (TMS) to reach a specific cortical target with modern focal stimulation coils has been intensively studied, the alignment and contact of a coil with the head is often ignored. Focal figure-of-eight coils have a point on the surface, where they generate the largest induced electric field. This point should touch the head first, and the coil should be approximately tangential to the head in this point. Previous research has demonstrated the large impact if the coil does not touch the head with the right point and that many operators struggle with establishing or maintaining the correct coil-scalp alignment. This paper presents a technological support technology that can monitor the exact position of the contact point and also pressure to provide feedback to users. As the system uses exclusively components from consumer electronics, the sensor is low-cost and affordable. Through proper design, we achieved sufficient robustness so that the sensor does neither reset during TMS pulses and also not show any detectable degradation.

2606.08614 2026-06-09 physics.app-ph eess.SP physics.class-ph 新提交

Acoustic Cloning

声学克隆

Jonas Müller, Theodor S. Becker, Xun Li, Johannes Aichele, Marc Serra-Garcia, Johan O. A. Robertsson, Dirk-Jan van Manen

AI总结 提出两步声学克隆方法:通过多维反卷积获取散射格林函数,再利用全息重建实时复制散射体,实验验证了二维波导中刚性散射体的克隆与修改。

Comments 17 pages, 14 figures. Author-prepared version of the article published in Phys. Rev. Applied 20, 064014 (2023). Supporting data: https://doi.org/10.5281/zenodo.16880576 Website: https://jmullerresearch.ch Contact: jmuller.research@gmail.com

Journal ref Phys. Rev. Applied 20, 064014 (2023)

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AI中文摘要

克隆是指产生现有对象的相同副本。在这里,我们实验展示了如何克隆声学散射对象。我们获取数字孪生并将其复活——一个简单的两步过程。首先,我们使用宽带扬声器在封闭的接收孔径内照射散射对象。从这些记录的混响数据中,我们通过多维反卷积检索对象的散射格林函数。第二步,使用获取的散射格林函数全息重建声学散射体。全息图实时散射任何波场,就像原始对象一样。低延迟反馈再现了物理波场与数值定义全息图之间的所有阶次相互作用。通过在一个二维声学波导中克隆和修改几个刚性散射体,演示了这一两步过程。应用范围从完全真实的数字散射模型到高效的超材料实验。

英文摘要

Cloning refers to producing identical copies of existing objects. Here, we experimentally show how to clone acoustic scattering objects. We acquire a digital twin and bring it back to life - a simple two-step process. First, we use broadband speakers to illuminate the scattering object within a closed receiver aperture. From these recorded reverberative data, we retrieve the object's scattering Green's functions using multidimensional deconvolution. In the second step, the acoustic scatterer is holographically reconstructed using the acquired scattering Green's functions. The hologram scatters any wavefield in real-time exactly like the original object would. Low-latency feedback reproduces all orders of interactions between the physical wavefield and the numerically defined hologram. This two-step process is demonstrated by cloning and modifying several rigid scatterers in a two-dimensional acoustic waveguide. Applications range from fully realistic digital scattering models to efficient metamaterial experimentation.

2606.08613 2026-06-09 cond-mat.str-el 新提交

Inhomogeneous Coulomb Models Without Defects are Sick: Domain Wall Energies Scaling as Volume (not Boundary Area)

无缺陷的非均匀库仑模型是有病的:畴壁能按体积(而非边界面积)标度

Garry Goldstein

AI总结 本文证明,在无缺陷的情况下,满足散度为零约束的库仑模型存在病态行为,畴壁能随系统体积而非边界面积标度,并给出方格六顶点模型、量子二聚体和经典自旋冰中的例子。

Comments Comments are welcome

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AI中文摘要

在这项工作中,我们展示了库仑模型——即满足 $\nabla\cdot\left\langle \mathbf{B}\right\rangle =0$ 无散约束的模型,其中 $\left\langle \mathbf{B}\right\rangle $ 是与晶格系统微观自由度相关的某些粗粒化变量——如果没有包含 $\nabla\cdot\mathbf{B}\neq0$ 的缺陷,则是有病的。我们证明,对于一般边界(其中边界上赝磁场的通量不抵消:$\left(\left\langle \mathbf{B}_{R}\right\rangle -\left\langle \mathbf{B}_{L}\right\rangle \right)\cdot\mathbf{n}\neq0$,这里 $\mathbf{n}$ 是单位法向,$\left\langle \mathbf{B}_{R/L}\right\rangle $ 是畴壁两侧的两个基态赝磁场),在没有缺陷的情况下,系统不同相之间的尖锐畴壁(宽度约为一个晶胞)的能量与系统大小(而非边界面积)成比例。我们在方格六顶点模型、量子二聚体以及存在磁场时的经典自旋冰中给出了这一现象的若干不同例子。我们还通过例子表明,条件 $\left(\left\langle \mathbf{B}_{R}\right\rangle -\left\langle \mathbf{B}_{L}\right\rangle \right)\cdot\mathbf{n}=0$ 是边界兼容的必要但非充分条件——即畴壁能按畴壁面积而非系统大小标度。为了进一步说明边界条件在库仑系统中的重要性,我们证明系统边界,即使满足 $\int_{\partial V}\mathbf{B}\cdot\mathbf{n}=0$,也具有热力学后果——即亥姆霍兹自由能存在一个与系统大小广延的代价。

英文摘要

In this work we show that coulomb models, ones that obey a $\nabla\cdot\left\langle \mathbf{B}\right\rangle =0$ divergence free constraint - for $\left\langle \mathbf{B}\right\rangle $ being some coarse grained variables related to the microscopic degrees of freedom of the lattice system - are sick without the inclusion of defects with $\nabla\cdot\mathbf{B}\neq0$. We show that for generic boundaries (ones where the fluxes of the pseudo-magnetic fields on the boundary do not cancel: $\left(\left\langle \mathbf{B}_{R}\right\rangle -\left\langle \mathbf{B}_{L}\right\rangle \right)\cdot\mathbf{n}\neq0$ - here $\mathbf{n}$ is the unit normal and $\left\langle \mathbf{B}_{R/L}\right\rangle $ are the two ground state pseudo-magnetic fields on either side of the domain wall) without the inclusion of defects, sharp domain walls (on the order of the width of a unit cell) between different phases of the system cost energy proportional to system size (not boundary area). We present several different examples of this phenomena in the square lattice six vertex model, in quantum dimers and in classical spin ice in the presence of magnetic fields. We also show by example that the condition $\left(\left\langle \mathbf{B}_{R}\right\rangle -\left\langle \mathbf{B}_{L}\right\rangle \right)\cdot\mathbf{n}=0$ is a necessary but not sufficient condition for the boundaries to be compatible - that is domain wall energy to scale with domain wall area and not system size. To further present the importance of boundary conditions in Coulomb systems we show that system boundaries, even ones that satisfy $\int_{\partial V}\mathbf{B}\cdot\mathbf{n}=0$, have thermodynamic consequences - that is there is a cost, extensive in system size, to the Helmholtz free energy.

2606.08609 2026-06-09 hep-ph hep-lat 新提交

Machine learning unveils the quark mass dependence of the pseudoscalar meson decay constants in three-flavour N$^2$LO ChPT

机器学习揭示三味N$^2$LO手征微扰论中赝标量介子衰变常数的夸克质量依赖性

Zejian Zhuang, Fernando Gil Domínguez, Raquel Molina

AI总结 利用LASSO机器学习方法分析格点QCD数据,精确确定三味N$^2$LO手征微扰论中赝标量介子衰变常数的夸克质量依赖性,并预测SU(3)极限下八重态重子质量。

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AI中文摘要

从三味N$^2$LO手征微扰论出发,确定了赝标量介子衰变常数$f_π, f_K$和$f_η$的夸克质量依赖性,直至接近SU(3)极限的约$780$ MeV的π介子质量。这是通过使用LASSO方法(一种机器学习技术)分析最近的格点QCD数据实现的,该方法能够高精度地确定相关的低能常数。由于π介子衰变常数是出现在相关唯象拉格朗日量或基于低能QCD的有效场论中的基本量,该分析可作为评估强子态夸克质量依赖性的输入。作为示例,我们在协变重子手征微扰论中预测了SU(3)极限下八重态重子的质量。

英文摘要

The quark mass dependence of the pseudoscalar meson decay consntants, $f_π, f_K$ and $f_η$, are determined from three-flavor N$^2$LO ChPT till pion masses around $780$ MeV, near the SU(3) limit. This is done by conducting an analysis of recent LQCD data using the LASSO method, a machine-learning technique which allows to pin down the relevant low-energy-constants with high precision. Since the pion decay constant is a fundamental quantity which usually appears in relevant phenomenological lagrangians or Effective Field Theories based on QCD at low energies, this analysis can be used as input to evaluate the quark mass dependence of hadronic states. As an example, we predict the masses of the octect baryons in the SU(3) limit within covariant Baryon Chiral Perturbation Theory.

2606.08608 2026-06-09 cond-mat.mtrl-sci 新提交

Divergent Coherent Phonon Responses Across the Metal-Insulator Crossover

跨越金属-绝缘体交叉的相干声子响应发散

Felix Hoff, Timo Veslin, Tim Bartsch, Carl-Friedrich Schön, Dante M. Kennes, Matthias Wuttig

AI总结 通过激光注量诱导的声子软化与相干反射振荡振幅,发现仅在中等电导率(102-104 S/cm)的金属-绝缘体交叉区域,材料表现出异常强的超快响应,归因于metavalent键合机制。

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AI中文摘要

材料性质的超快激光控制依赖于对光-物质相互作用的理解。我们使用两个实验可观测的响应函数——激光注量诱导的声子软化与相干反射振荡振幅——来比较不同材料对超快光激发的响应强度。通过比较多种材料,我们发现仅有一小类材料(包括Sb、GeTe和Bi2Te3)表现出异常响应,例如显著的声子软化以及随注量增加反射振荡的巨幅增长。这些响应函数在局域与离域电子态交叉的中等电导率区间(约102-104 S/cm)达到峰值。相应的固体类别还表现出其他非常规性质,包括高介电常数、增强的玻恩有效电荷、超过8-N规则的配位数以及不常见的键断裂。这表明这些材料采用了一种独特的键合机制,称为metavalent键合。冻结声子DFT计算表明,强烈的注量依赖性源于Peierls型不稳定性,导致大的形变势和非简谐双阱势。这些发现将metavalent键合识别为增强相干声子控制的设计原则,并为识别具有异常超快响应的材料提供了定量框架。

英文摘要

Ultrafast laser control of material properties hinges on understanding light-matter interactions. We use two experimentally accessible response functions, laser fluence induced phonon softening and the amplitude of coherent reflectance oscillations, to compare how strongly different materials respond to ultrafast photoexcitation. Comparing a diverse set of materials, we find that only a narrow class, including Sb, GeTe, and Bi2Te3, shows exceptional responses such as pronounced phonon softening and a giant increase of reflectance oscillations with increasing fluence. These response functions peak in an intermediate conductivity regime of about 102 - 104 S/cm, at the crossover between localized and delocalized electronic states. The corresponding class of solids also shows other unconventional properties including high dielectric constants, enhanced Born effective charges, coordination numbers exceeding the 8-N rule and uncommon bond rupture. This suggests that these materials employ a unique bonding mechanism, coined metavalent bonding. Frozen-phonon DFT calculations show that the strong fluence dependence arises from Peierls-like instabilities, leading to large deformation potentials and anharmonic double-well potentials. These findings identify metavalent bonding as a design principle for enhanced coherent phonon control and provide a quantitative framework for identifying materials with exceptional ultrafast responses.

2606.08607 2026-06-09 astro-ph.GA astro-ph.SR 新提交

ALMA High-resolution Observation of the HH46/47 Outflow/disk/envelope System

HH46/47 外流/盘/包层系统的 ALMA 高分辨率观测

Heyi Zhang, Yichen Zhang, Héctor G. Arce, Diego Mardones, Sylvie Cabrit, Michael M. Dunham, Stella S. R. Offner, Hsien Shang

AI总结 利用 ALMA 0.1角秒分辨率观测 HH 46/47 分子外流及其盘-包层系统,揭示了环绕双星盘的亚结构、伴星引起的扰动以及离心势垒附近的快速旋转结构,并通过 CO 多谱线分析外流壳层的三维速度场,支持卷吸机制而非盘风起源。

Comments 39 pages, 23 figures. Submitted to ApJ; Comments are welcome

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AI中文摘要

我们展示了 HH 46/47 分子外流及其包层-盘系统的 0.1角秒(约 50 au)分辨率阿塔卡马大型毫米/亚毫米阵列(ALMA)观测结果。1.3 mm 连续谱辐射揭示了一个致密中心源,周围环绕着一个具有亚结构的双星盘。在光学和红外观测中识别的伴星在毫米连续谱中未被探测到,但与局部强度最小值重合。从主星向伴星延伸的两个类似尖刺的特征被识别出来,很可能是由伴星的引力扰动引起的。包层-盘系统由 C18O、SO、H2CO 和 CH3OH 示踪。C18O 主要示踪延展的包层,而 SO 探测内部包层,H2CO 和 CH3OH 示踪离心势垒附近紧凑、快速旋转的结构。观测结果很好地再现了旋转下落包层在半径约 30 au 处过渡到围绕 0.3 M☉ 原恒星的内盘。12CO 发射与 JWST NIRCam 图像一起揭示了外流中的多个壳层结构。利用 C18O 和 13CO 校正光学深度,我们推导出外流质量、动量和动能的空间分布及其相应的速率。对一个定义良好的红移壳层进行模型无关分析,得到了其三维速度场,表明壳层径向膨胀而非沿其表面流动。尽管检测到了横向速度梯度,但将其解释为旋转意味着非物理的大磁力臂,不利于直接的盘风起源。相反,壳层运动学支持卷吸机制。

英文摘要

We present 0.1" (~ 50 au) resolution Atacama Large Millimeter/submillimeter Array (ALMA) observations of the HH 46/47 molecular outflow and its envelope-disk system. The 1.3 mm continuum emission reveals a compact central source surrounded by a circumbinary disk with substructures. The companion, identified in optical and infrared observations, is not detected in the millimeter continuum but coincides with a local intensity minimum. Two spur-like features extending from the primary source toward the companion are identified and are likely induced by gravitational perturbations from the companion. The envelope-disk system is traced by C18O, SO, H2CO, and CH3OH. C18O primarily traces the extended envelope, while SO probes the inner envelope, and H2CO and CH3OH trace compact, faster-rotating structures near the centrifugal barrier. The observations are well reproduced by a rotating-infalling envelope transitioning to an inner disk at a radius of ~30 au around a 0.3 Msun protostar. The 12CO emission, together with JWST NIRCam images, reveals multiple shell structures in the outflow. Using C18O and 13CO to correct for optical depth, we derive the spatial distributions of outflow mass, momentum, and kinetic energy, as well as their corresponding rates. A model-independent analysis of a well-defined redshifted shell yields its three-dimensional velocity field, showing that the shell expands radially rather than flowing along its surface. Although a transverse velocity gradient is detected, interpreting it as rotation implies an unphysically large magnetic lever arm, disfavoring a direct disk-wind origin. Instead, the shell kinematics support an entrainment scenario.

2606.08606 2026-06-09 quant-ph cond-mat.stat-mech cond-mat.str-el hep-th 新提交

Hidden Conformal Boundary Data in Finite-Temperature Stabilizer Entropy

有限温度稳定子熵中的隐藏共形边界数据

Reyhaneh Khasseh, M. A. Rajabpour

AI总结 研究开放临界量子自旋链在有限温度下的稳定子Rényi熵,通过Pfaffian表示揭示块Toeplitz-Hankel结构,发现标度函数为level-eight eta商,表明存在隐藏的缺陷型共形数据。

Comments 41 pages + 10 Figures

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AI中文摘要

我们研究了开放临界量子自旋链在有限温度下的稳定子Rényi熵。在Rényi指数为二分之一时,该可观测量探测了热Pauli弦期望值的分布,并可表示为横场Ising链有限温度关联矩阵的所有平方子式的绝对值之和。我们证明了这个指数级大的和可精确约化为单个Pfaffian。该Pfaffian表示揭示了块Toeplitz-Hankel结构,并使我们能够提取多个热区间的尺寸标度。在逆温度与系统尺寸成比例的交叉窗口中,稳定子熵分解为一个饱和的广延贡献和一个普适的有限尺寸标度函数。我们发现该标度函数是一个level-eight eta商,而非通常的自由边界Majorana热因子。该偏差在低温下指数级隐藏,但控制着高温交叉行为,在那里它给出了Pauli弦期望权重谱的Cardy-like渐近形式。这些结果表明,有限温度稳定子熵揭示了普通热力学探针无法观测到的隐藏缺陷型共形数据。

英文摘要

We study the finite-temperature stabilizer Rényi entropy of the open critical quantum spin chains. At Rényi index one half, this observable probes the distribution of thermal Pauli-string expectation values and can be written as a sum over absolute values of all square minors of a finite-temperature correlation matrix for the transverse-field Ising chain. We show that this exponentially large sum is exactly reducible to a single Pfaffian. The Pfaffian representation reveals a block Toeplitz--Hankel structure and allows us to extract the large-size scaling in several thermal regimes. In the crossover window where the inverse temperature is proportional to the system size, the stabilizer entropy factorizes into a saturated extensive contribution and a universal finite-size scaling function. We find that this scaling function is a level-eight eta quotient, rather than the ordinary free-boundary Majorana thermal factor. The deviation is exponentially hidden at low temperature but controls the high-temperature crossover, where it gives a Cardy-like asymptotic for the Pauli-string expectation-weight spectrum. These results show that finite-temperature stabilizer entropy reveals hidden defect-like conformal data invisible to ordinary thermodynamic probes.

2606.08603 2026-06-09 hep-th hep-ph 新提交

Self-Gravitating Magnetic Monopoles and Dyons in String-Inspired Models: Structure and Stability

弦启发模型中的自引力磁单极子和戴恩:结构与稳定性

Nick E. Mavromatos, Sarben Sarkar, Dionysios P. Theodosopoulos

AI总结 研究弦启发模型中由整体单极子诱导的磁单极子和戴恩解,考虑引力、Born-Infeld电动力学及膨胀子和轴子场,证明解满足能量条件且线性稳定。

Comments 30 pages revtex, several pdf figures incorporated

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AI中文摘要

我们给出了在引力存在下,弦启发模型中由整体单极子诱导的磁单极子和戴恩的经典解。分析了两种不同的场景。第一种,磁单极子来自非平凡的无质量膨胀子场与电磁(EM)扇区的耦合。第二种,戴恩解出现在非平凡的Kalb-Ramond(KR)轴子场和无质量膨胀子场存在的情况下,该膨胀子场耦合了KR和EM扇区。在两个模型中,单极子和戴恩构型均源于与全局O(3)对称性自发破缺相关的整体单极子。EM扇区由Born-Infeld电动力学描述,确保了单极子核心处场的正则性和有限的自能。所得解代表具有明确核心和正ADM(Arnowitt-Deser-Misner)质量的类粒子构型,并满足所有标准能量条件。我们还证明了在质量为零的磁单极子极限情况下存在非零的最小磁荷。我们还讨论了磁单极子和戴恩解的稳定性判据。首先证明了这些解的力学稳定性判据得到满足,这要求总力分量有限且径向分量指向外,表明避免了坍缩。接下来,我们在Gervalle-Volkov框架内,在Einstein-Born-Infeld-膨胀子-轴子理论中分析了自引力Born-Infeld单极子和戴恩解的动力学(线性扰动)稳定性,并证明了单极子和戴恩构型在外部区域对电磁扰动是线性稳定的,其中戴恩由于轴子诱导的混合而表现出双折射螺旋性结构。

英文摘要

We present classical solutions for magnetic monopoles and dyons induced by global monopoles for string-inspired models, in the presence of gravity. Two distinct scenarios are analyzed. In the first, magnetic monopoles arise from the coupling of a non-trivial massless dilaton field to the electromagnetic (EM) sector. In the second, dyonic solutions emerge in the presence of a non-trivial Kalb-Ramond (KR) axion field and a massless dilaton field, which couples the KR and EM sectors. In both models, the monopole and dyon configurations originate from a global monopole associated with the spontaneous breaking of a global O(3) symmetry. The EM sector is described by Born-Infeld electrodynamics, ensuring regularity of the fields at the core of the monopole and a finite self-energy. The resulting solutions represent particle-like configurations with a well-defined core and positive ADM (Arnowitt-Deser-Misner) mass, and are shown to satisfy all standard energy conditions. We also demonstrate the existence of a minimum nonzero magnetic charge in the limiting case of a magnetic monopole with vanishing mass. We also discuss stability criteria for our magnetic-monopole and dyon solutions. We first demonstrate that the mechanical-stability criteria for these solutions are satisified. These require the finiteness of the total force components and also the outward-pointing nature of the radial component, which indicates the avoidance of collapse. Next we analyse the dynamical (linear perturbative) stability of the self-gravitating Born-Infeld monopole and dyon solutions within Einstein-Born--Infeld-dilaton-axion theory in the Gervalle-Volkov framework, and demonstrate that both monopole and dyonic configurations are linearly stable against electromagnetic perturbations in the exterior region, with dyons exhibiting a birefringent helicity structure due to axion-induced mixing.

2606.08600 2026-06-09 math.FA 新提交

Crescents and the real variable Cesaro operator

新月形与实变量Cesàro算子

Anil Belli, Ugur Gul, William T. Ross, Aristos Siskakis

AI总结 本文研究Lebesgue空间L^p(0,1)上Cesàro积分算子的范数、谱性质、循环性和不变子空间,其谱为依赖于p的新月形区域,关键工具是加权复合算子半群。

Comments 20 pages, 8 figures

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AI中文摘要

本文探讨了Lebesgue空间$L^p(0, 1)$上经典Cesàro积分算子的一种形式,讨论了其范数、谱性质、循环性和不变子空间。Cesàro算子的谱将是一个新月形区域,其几何形状依赖于$p$。一个重要工具是$L^p(0, 1)$上的加权复合算子半群。

英文摘要

This paper explores a version of the classical Cesàro integral operator for the Lebesgue space $L^p(0, 1)$ where we discuss its norm, spectral properties, cyclicity, and invariant subspaces. The spectrum of the Cesàro operator will be a crescent domain whose geometry depends on $p$. An important tool will be semigroups of weighted composition operators on $L^p(0, 1)$.

2606.08599 2026-06-09 math.AG math.CV math.DG 新提交

Projective subvarieties of Bogomolov-Guan manifolds and quasi-diagonals in products of elliptic curves

Bogomolov-Guan 流形的射影子簇与椭圆曲线乘积中的拟对角线

Leila Abubakarova, Alexandra Kuznetsova, Misha Verbitsky

AI总结 研究非凯勒全纯辛流形 Bogomolov-Guan 中的复子簇,通过拟对角线分类射影子簇,证明一般情形下射影子簇属于Lagrangian纤维的纤维。

Comments 46 pages, version 1.0

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AI中文摘要

我们研究某些非凯勒全纯辛流形 $X$ 中的复子簇,称为 Bogomolov-Guan 流形。设 $E$ 为椭圆曲线,$L$ 为 $E$ 上的丰沛线丛,$S\subset E^2$ 为复曲线,$p_1, p_2$ 为 $S$ 到 $E$ 的相应投影。若 $p_1^*L\otimes p_2^* L^{-1}$ 是挠线丛,则曲线 $S$ 称为拟对角线。我们证明,对任意 $(E,L)$,至多存在可数条拟对角线。利用拟对角线,我们分类了 Bogomolov-Guan 流形中的射影子簇。Bogomolov-Guan 流形配备有 Lagrangian 纤维化 $π:\\; X \to {\Bbb C} P^n$。我们证明,不可约复子簇 $Z\subset X$ 是 Moishezon 的当且仅当 $π(Z)$ 是一个点或某个由拟对角线描述的复曲线。这用于证明,对一般的 Bogomolov-Guan 流形,任何射影子簇都属于 $π$ 的某个纤维。

英文摘要

We study complex subvarieties in certain non-Kahler holomorphically symplectic manifolds $X$, called the Bogomolov-Guan manifolds. Let $E$ be an elliptic curve, $L$ an ample line bundle on $E$, $S\subset E^2$ a complex curve, and $p_1, p_2$ the corresponding projections of $S$ to $E$. The curve $S$ is called a quasi-diagonal if $p_1^*L\otimes p_2^* L^{-1}$ is a torsion line bundle. We show that there are at most countably many quasi-diagonals for any $(E,L)$. Using the quasi-diagonals, we classify the projective subvarieties in the Bogomolov-Guan manifold. The Bogomolov-Guan manifold is equipped with a Lagrangian fibration $π:\; X \to {\Bbb C} P^n$. We show that an irreducible complex subvariety $Z\subset X$ is Moishezon if and only if $π(Z)$ is a point or a certain complex curve which is described in terms of quasi-diagonals. This is used to prove that for a general Bogomolov-Guan manifold, any projective subvariety belongs to a fiber of $π$.

2606.08598 2026-06-09 astro-ph.HE 新提交

Discovery of a Candidate 2 keV Cyclotron Resonance Scattering Feature in the HLX NGC 3583 X-1

在HLX NGC 3583 X-1中发现候选2 keV回旋共振散射特征

Kiran M. Jayasurya, Aman Upadhyay, Vikram Rana

AI总结 利用多波段X射线数据,在超亮X射线源NGC 3583 X-1中检测到约2 keV的吸收线,解释为候选质子回旋共振散射特征,表明存在强磁场中子星。

Comments 20 pages, 9 figures. Revised version submitted to The Astrophysical Journal

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AI中文摘要

我们利用存档的XMM-Newton、NuSTAR、Chandra数据和长期Swift/XRT监测,对星系NGC 3583中的暂现超亮X射线源(HLX)2SXPS J111416.1+481833进行了宽带X射线研究。该源间歇性地进入超亮状态,X射线光度$L_X > 10^{41}$ erg s$^{-1}$,并从峰值下降超过45倍进入深低态。我们在宽带谱中检测到清晰的谱截止在$\sim$5-6 keV,这些谱很好地由软热成分与光学厚热康普顿化或内流主导吸积盘模型拟合。在XMM-Newton谱中,我们检测到统计显著($\gtrsim 3.9 σ$)的吸收线,中心能量$E_{\rm line} \approx 1.97 \pm 0.04$ keV,宽度$σ_{\rm line} \approx 74 \pm 40$ eV。我们主要将该线解释为候选质子回旋共振散射特征(CRSF),意味着局部磁场强度$B \sim 4 \times 10^{14}$ G。我们探索了其他解释,如电离外流起源,但发现可能性较小。我们未检测到相干X射线脉动,在0.3-10 keV波段脉冲分数上限为19.3%,在3-15 keV波段为36.3%(90%置信度)。极端光度、硬谱状态以及候选回旋线的探测为高度磁化中子星吸积体提供了有力证据。

英文摘要

We present a broadband X-ray study of the transient hyperluminous X-ray source (HLX), 2SXPS J111416.1+481833, in the galaxy NGC 3583, using archival XMM-Newton, NuSTAR, Chandra data, and long-term Swift/XRT monitoring. The source episodically enters the hyperluminous regime with X-ray luminosities $L_X > 10^{41}$ erg s$^{-1}$ and drops by a factor of $>45$ from its peak into a deep low state. We detect a clear spectral cutoff at $\sim$5-6 keV in the broadband spectra, which are well modeled by a soft thermal component combined with optically thick thermal Comptonization or an inner advection-dominated disk. In the XMM-Newton spectra, we detect a statistically significant ($\gtrsim 3.9 σ$) absorption line centered at $E_{\rm line} \approx 1.97 \pm 0.04$ keV with a width of $σ_{\rm line} \approx 74 \pm 40$ eV. We primarily interpret the line as a candidate proton Cyclotron Resonance Scattering Feature (CRSF), implying a local magnetic field strength of $B \sim 4 \times 10^{14}$ G. Alternative interpretations, such as an origin in an ionized outflow, were explored and found to be less likely. We do not detect coherent X-ray pulsations, placing 90% confidence upper limits on the pulsed fraction of 19.3% in the 0.3-10 keV band and 36.3% in the 3-15 keV band. The combination of extreme luminosity, a hard spectral state, and the detection of a candidate cyclotron line provides strong evidence for a highly magnetized neutron star accretor.

2606.08597 2026-06-09 cs.DS math.CO 新提交

Kikuchi Graphs of Random Hypergraphs are Approximately Johnson

随机超图的Kikuchi图近似Johnson图

Pravesh K. Kothari

AI总结 证明随机2r-均匀超图的level-ℓ Kikuchi图在谱上近似完全2r-均匀超图的Kikuchi图,采样率在r≤ℓ≤n/2范围内达到对数因子内的最优,基于矩阵Bernstein不等式应用于Johnson特征空间的块,并应用于Max 2r-XOR问题的平方和松弛的完整性证明。

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AI中文摘要

我们证明,在 $r\leq \ell \leq n/2$ 的范围内,随机 $2r$-均匀超图的 level-$\ell$ Kikuchi 图在谱上近似完全 $2r$-均匀超图的 Kikuchi 图,其采样率在至多一个对数因子的意义下是精确的。我们的证明基于矩阵 Bernstein 不等式,但与先前的工作不同,我们将其应用于 Johnson 特征空间的适当块集合。我们的分析依赖于任意 Kikuchi 图的一个新的、简单的带局部性质。作为一个应用,我们证明,当输入是一个在随机超图上的 planted noisy $2r$-XOR 实例,且超边数为 $\gtrsim n \cdot (n/\ell)^{r-1} \log n$ 时,Max $2r$-XOR 问题的自然 degree-$2\ell$ 平方和松弛是“完整的”。

英文摘要

We prove that level-$\ell$ Kikuchi graphs of random $2r$-uniform hypergraphs spectrally approximate the Kikuchi graph of the complete $2r$-uniform hypergraph at a sampling rate that is sharp up to a logarithmic factor, in the regime $r\leq \ell \leq n/2$. Our proof is based on the matrix Bernstein inequality, but, unlike prior works, we apply it to an appropriate collection of blocks of Johnson eigenspaces. Our analysis relies on a new, simple band-locality property for arbitrary Kikuchi graphs. As an application, we prove that the natural degree-$2\ell$ sum-of-squares relaxation for the Max $2r$-XOR problem is ``integral'' when the input is a planted noisy $2r$-XOR instance on a random hypergraph with $\gtrsim n \cdot (n/\ell)^{r-1} \log n$ hyperedges.

2606.08595 2026-06-09 quant-ph gr-qc hep-th 新提交

Is Exact Markovianity Fundamental Once Time Is Relational?

一旦时间是关系性的,精确马尔可夫性是否基本?

Partha Nandi, Francesco Petruccione

AI总结 通过有限分辨率量子钟的关系性表述,推导出相对论开放量子动力学,证明精确马尔可夫演化是有效的而非基本的。

Comments Manuscript length: 12 pages, including 1 figure. Supplementary documents are provided as supporting material

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AI中文摘要

马尔可夫开放量子理论假设相对于外部经典时间参数的演化,然而在相对论物理学中,不存在基本的优先时间概念。我们通过有限分辨率的量子钟,以关系性方式表述相对论开放量子动力学,解决了这一矛盾。利用Schwinger-Tomonaga形式,我们直接在时空超曲面上推导出协变主方程,并表明即使对于局域相互作用,所得的约化动力学通常也是非马尔可夫的。环境关联和时钟涨落共同生成记忆核,而Gorini-Kossakowski-Lindblad-Sudarshan (GKLS)结构仅在关系性粗粒化后出现,这意味着精确马尔可夫演化是有效的而非基本的。在尖锐时钟极限下,该形式简化为Anastopoulos-Hu引力退相干方程。

英文摘要

Markovian open quantum theory assumes evolution with respect to an external classical time parameter, yet no preferred notion of time exists fundamentally in relativistic physics. We resolve this tension by formulating relativistic open quantum dynamics relationally through finite-resolution quantum clocks. Using the Schwinger-Tomonaga formalism, we derive a covariant master equation directly on spacetime hypersurfaces and show that the resulting reduced dynamics is generically non-Markovian even for local interactions. Environmental correlations and clock fluctuations jointly generate the memory kernel, while the Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) structure emerges only after relational coarse-graining, implying that exact Markovian evolution is effective rather than fundamental. In the sharp-clock limit, the formalism reduces to the Anastopoulos-Hu gravitational decoherence equation.

2606.08593 2026-06-09 astro-ph.CO 新提交

Bayesian Reconstruction of the Local Universe from 2MRS: Testing the Gravitational Flow with Cosmicflows-4

从2MRS贝叶斯重建本地宇宙:用Cosmicflows-4检验引力流

Adi Nusser

AI总结 基于2MRS数据,采用贝叶斯方法重建本地密度和速度场,并通过与CF4独立本动速度比较,验证了重建引力流在大尺度上的准确性。

Comments 21 pages, 7 figures

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AI中文摘要

我们展示了由2MASS红移巡天(2MRS)示踪的本地密度和速度场的贝叶斯重建,并利用独立的Cosmicflows-4(CF4)星系群本动速度检验了推断的引力流。基准重建是Zel'dovich近似正向模型的最大后验(MAP)解,通过未分箱的泊松点过程似然受2MRS红移空间分布约束。该模型假设高斯初始条件,并包括2MRS选择函数、隐匿带、红移空间畸变以及距离依赖的星系偏置描述。哈密顿蒙特卡洛在同一框架内提供后验样本和约束实现。重建的速度场在逐个天体、密度-速度相关和逐层反射偶极测试中与CF4吻合良好。这些比较是在CF4红移空间位置进行的,不需要将观测到的CF4速度平滑到MAP分辨率。我们还用Gadget-4演化约束初始条件。实空间密度保留了Zel'dovich大尺度结构,同时发展出额外的非线性小尺度结构,红移空间分布则出现非线性“上帝手指”。结果表明,2MRS场级重建捕捉了近邻宇宙的大尺度引力流,并为约束模拟提供了合适的初始条件。

英文摘要

We present a Bayesian reconstruction of the local density and velocity fields traced by the 2MASS Redshift Survey (2MRS) and test the inferred gravitational flow against independent Cosmicflows-4 (CF4) galaxy-group peculiar velocities. The fiducial reconstruction is the maximum-a-posteriori (MAP) solution of a Zel'dovich-approximation forward model, constrained by the 2MRS redshift-space distribution through an unbinned Poisson point-process likelihood. The model assumes Gaussian initial conditions and includes the 2MRS selection function, the Zone of Avoidance, redshift-space distortions, and a distance-dependent galaxy-bias prescription. Hamiltonian Monte Carlo provides posterior samples and constrained realizations within the same framework. The reconstructed velocity field agrees well with CF4 in object-by-object, density--velocity-correlation, and shell-by-shell reflex-dipole tests. These comparisons are made at the CF4 redshift-space positions and do not require smoothing the observed CF4 velocities to the MAP resolution. We also evolve constrained initial conditions with Gadget-4. The real-space density retains the large-scale Zel'dovich structure while developing additional nonlinear small-scale structure, and the redshift-space distribution develops nonlinear Fingers of God. The results show that the 2MRS field-level reconstruction captures the large-scale gravitational flow of the nearby Universe and provides initial conditions suitable for constrained simulations.

2606.08591 2026-06-09 math.GR 新提交

On the normal subgroups of a split extension

关于分裂扩张的正规子群

Prashun Kumar

AI总结 本文通过N和Q的正规子群描述半直积G=N⋊Q的正规子群,其中N和Q是互素的有限群,并给出循环Sylow子群的有限群的正规子群完全列表。

Comments 10 pages

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AI中文摘要

设$N$和$Q$是有限群,且$\gcd(|N|,|Q|) = 1$。本文通过$N$和$Q$的正规子群描述$G = N \rtimes Q$的正规子群。设$p$和$q$是不同的素数。设$\mathfrak{A}_p$为初等阿贝尔$p$-群的簇。设$\mathfrak{A}_p\mathfrak{A}_q$为$\mathfrak{A}_p$中群被$\mathfrak{A}_q$中群扩张的簇。我们还提供了一种确定簇$\mathfrak{A}_p\mathfrak{A}_q$中群的正规子群的方法。此外,我们给出了具有循环Sylow子群的有限群的正规子群的完全列表。

英文摘要

Let $N$ and $Q$ be a finite groups with $\gcd(|N|,|Q|) = 1$. In this paper we describe normal subgroups of $G = N \rtimes Q$ via normal subgroups of $N$ and $Q$. Let $p$ and $q$ be distinct primes. Let $\mathfrak{A}_p$ be the variety of elementary abelian $p$-groups. Let $\mathfrak{A}_p\mathfrak{A}_q$ be the variety of extensions of a group in $\mathfrak{A}_p$ by a group in $\mathfrak{A}_q$. We also provide a method of determining the normal subgroups of a group in the variety $\mathfrak{A}_p\mathfrak{A}_q$. We also provide the complete list of normal subgroups of a finite group with cyclic Sylow subgroups.

2606.08588 2026-06-09 cs.SE 新提交

LLM vs. Human Unit Tests: Fault Detection on Real Python Bugs

LLM vs. 人类单元测试:对真实 Python 错误的故障检测

Phouvadeth Vathana, Prapti Bhatt, Rishi Patel, Nasir U. Eisty

AI总结 通过对比 LLM 生成与人工编写的单元测试在真实 Python 错误上的故障检测能力,发现 LLM 结合检索增强上下文可检测 69% 的故障,远超人工测试的 17.2%,且代码覆盖率相近,表明覆盖率不足以衡量故障检测能力。

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AI中文摘要

大型语言模型(LLM)在自动化单元测试生成方面显示出巨大潜力,但其相对于人工编写测试的实际有效性仍不明确。现有评估通常依赖面向覆盖率的基准测试,无法直接评估故障检测能力。我们在三个互补的 Python 基准测试上对 LLM 生成和人工编写的单元测试进行了实证比较:来自 BugsInPy 的 29 个真实历史错误、一个基于 python-slugify 和 packaging 的函数级基准测试,以及一个受控配对基准测试。我们的生成流程将 Gemini 2.5 Flash 与轻量级词汇检索机制相结合,在生成时提供与错误相关的上下文。在八个质量维度上,使用检索增强上下文的 LLM 生成测试在 69% 的案例中检测到故障,而通用人工编写测试仅为 17.2%(Fisher 精确检验,$p < 0.001$,Cohen's $h = 1.10$)。关键的是,两种方法之间的行覆盖率和分支覆盖率几乎相同(84.8% vs. 88.5% 和 75.2% vs. 82.1%),证实覆盖率不足以作为故障检测能力的代理指标。我们讨论了每种方法擅长的条件,描述了它们的互补优势,并指出了检索上下文和可重复基准测试构建在有意义的测试质量评估中的关键作用。

英文摘要

Large language models (LLMs) have shown considerable promise for automated unit test generation, yet their practical effectiveness relative to human-written tests remains poorly understood. Existing evaluations commonly rely on coverage-oriented benchmarks that do not assess fault-detection capability directly. We present an empirical comparison of LLM-generated and human-written unit tests across three complementary Python benchmarks: 29 real historical bugs from BugsInPy, a function-level benchmark drawn from python-slugify and packaging, and a controlled paired benchmark. Our generation pipeline couples Gemini 2.5 Flash with a lightweight lexical retrieval mechanism that supplies bug-relevant context at generation time. Across eight quality dimensions, LLM-generated tests with retrieval-augmented context detect faults in 69% of cases compared to 17.2% for general-purpose human-written tests (Fisher's exact, $p < 0.001$, Cohen's $h = 1.10$). Critically, line and branch coverage are nearly identical between the two approaches (84.8% vs. 88.5% and 75.2% vs. 82.1%), confirming that coverage is an insufficient proxy for fault-detection capability. We discuss the conditions under which each approach excels, characterize their complementary strengths, and identify the critical role of retrieval context and reproducible benchmark construction in meaningful test-quality evaluation.

2606.08586 2026-06-09 q-fin.ST 新提交

Cross-sectional topological anomaly scores and intraday return predictability in the S&P 500: A BallMapper, decoder-conditional VAE, and Function-on-Function regression approach

标普500中的横截面拓扑异常分数与日内收益可预测性:BallMapper、解码器条件变分自编码器和函数对函数回归方法

Krzysztof Ozimek

AI总结 本文构建基于市场拓扑结构和横截面同行背景的股票级拓扑异常分数,通过函数对函数回归验证其对标普500成分股日内收益曲线的预测能力,发现异常分数具有累积、反转和分布式的预测特征。

Comments 25 pages, 1 figure, 8 tables

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AI中文摘要

金融时间序列中的异常检测方法通常对可观测数据中的统计异常观测值进行评分,而非对共同运动潜在结构中拓扑上不符合预期的持续偏差进行评分。本研究构建了一个股票级拓扑异常分数,该分数同时以市场级拓扑结构和横截面同行背景为条件,并检验其历史是否包含对收益曲线的预测内容。使用Takens延迟嵌入对十只流动性强的标普500成分股(2025年4月至2026年3月)的日内数据进行嵌入,通过BallMapper进行图构建,并由三种解码器条件变分自编码器变体进行评分。预测内容通过惩罚函数对函数回归进行评估,并在所有资产、日内柱频率和评分变体中得到确认,揭示了一致的时间特征——收益影响的逐渐累积、其方向的频繁早期反转,以及广泛分布的、偏向近期异常历史的预测内容。反转发生的时间取决于市场状态;异常历史对预测的贡献均匀程度取决于柱频率。

英文摘要

Anomaly detection methods in financial time series score statistically unusual observations in observable data, not topologically misexpected persistent deviations in the latent structure of co-movement. This study constructs a stock-level topological anomaly score jointly conditioned on market-level topological structure and cross-sectional peer context, and tests whether its history carries predictive content for return curves. Intraday data for ten liquid S&P 500 constituents (April 2025--March 2026) are embedded via Takens delay embedding, graphed by BallMapper, and scored by three decoder-conditional variational autoencoder variants. Predictive content is assessed by penalised function-on-function regression and confirmed across all assets, intraday bar frequencies, and scoring variants, revealing a consistent temporal fingerprint -- gradual accumulation of return impact, a frequent early reversal of its direction, and broadly distributed predictive content weighted toward recent anomaly history. When the reversal occurs depends on market regime; how evenly the anomaly history contributes to prediction depends on bar frequency.

2606.08585 2026-06-09 math.NA cs.NA 新提交

Novel physical property preserved methods for stochastic Schrödinger--KdV equation

随机Schrödinger--KdV方程的新型物理性质保持方法

Ziheng Chen, Jialin Hong, Liying Sun

AI总结 针对加性噪声驱动的随机Schrödinger-KdV方程,建立了平均物理量演化律,并发展了两种保持离散物理定律的时间离散化方法(分裂-Crank-Nicolson格式和常数标量辅助变量格式),与局部间断Galerkin方法结合得到结构保持全离散格式。

Comments 24 pages, 12 figures

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AI中文摘要

本文从分析和数值两个角度研究加性噪声驱动的随机Schrödinger--KdV方程。我们首先建立了平均等离子体数、动量和能量的演化律,以及平均粒子数的守恒律。受这些内在结构的启发,我们发展了两种时间离散化方法。一种基于分裂策略和Crank-Nicolson格式构建,并证明其保持了平均等离子体数和动量的离散演化律以及平均粒子数的离散守恒律。另一种在常数标量辅助变量框架下提出,其中非线性能量泛函被重新表述,使得可以在离散层面保持修正的平均能量律。将这些时间离散化与空间上的局部间断Galerkin逼近相结合,得到了继承相应离散物理定律的结构保持全离散格式。数值实验验证了理论结果,并展示了所提方法的准确性、鲁棒性和有效性。

英文摘要

In this work, we study the stochastic Schrödinger--KdV equation driven by additive noise from both analytical and numerical viewpoints. We first establish the evolution laws for the averaged plasmon number, momentum, and energy, together with the conservation of the averaged particle number. Motivated by these intrinsic structures, we develop two temporal discretizations. One is constructed based on the splitting strategy and Crank--Nicolson scheme, and is shown to preserve the discrete evolution laws of the averaged plasmon number and momentum, as well as the discrete conservation law of the averaged particle number. The other is proposed within the constant scalar auxiliary variable framework, in which the nonlinear energy functional is reformulated so that a modified averaged energy law can be preserved at the discrete level. Combining these temporal discretizations with a local discontinuous Galerkin approximation in space yields structure-preserving full discretizations inheriting the corresponding discrete physical laws. Numerical experiments are presented to validate the theoretical results and to demonstrate the accuracy, robustness, and effectiveness of the proposed methods.

2606.08582 2026-06-09 hep-th 新提交

Soft Algebra for ${\cal N}=4$ SYM

${\cal N}=4$ SYM 的软代数

Luis F. Alday, Andrew Strominger

AI总结 本文为平面 ${\cal N}=4$ 超 Yang-Mills 理论提出一种全阶因子化定义,使得硬振幅满足未修正的树级软定理,并实现未变形树级 $\cal S$-代数的表示。

Comments 41 pages

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AI中文摘要

非阿贝尔规范理论中 $n$ 个粒子的散射振幅具有一般形式 $\mathcal{A}_n = \mathcal{A}^{\rm soft}_n \times \mathcal{A}^{\rm hard}_n$ 的因子化,其中 $\mathcal{A}^{\rm soft}_n$ 是红外发散的,而 $\mathcal{A}^{\rm hard}_n$ 是红外有限的并编码了更高圈对散射的修正。我们为平面 ${\cal N}=4$ 超 Yang-Mills (SYM) 指定了这种因子化的一个特定全阶定义,并论证了得到的 $\mathcal{A}_n^{\rm hard}$ 满足未修正的树级软定理。此外,它提供了由软胶子塔生成的未变形树级 $\cal S$-代数的一个表示。这些结果来自 ${\cal N}=4$ SYM 的几个常用假设,包括 BDS 单圈指数化分裂函数以及振幅/威尔逊圈对偶。

英文摘要

Scattering amplitudes of $n$ particles in nonabelian gauge theories admit factorizations of the general form $\mathcal{A}_n \;=\; \mathcal{A}^{\rm soft}_n \times \mathcal{A}^{\rm hard}_n$, where $\mathcal{A}^{\rm soft}_n$ is IR divergent, while $\mathcal{A}^{\rm hard}_n$ is IR finite and encodes the higher loop corrections to scattering. We specify a particular all-orders definition of this factorization for planar ${\cal N}=4$ super Yang-Mills (SYM) and argue that the resulting $\mathcal{A}_n^{\rm hard}$ obeys an uncorrected tree-level soft theorem. Moreover it furnishes a representation of the undeformed tree-level $\cal S$-algebra generated by a tower of soft gluons. The results follow from several commonly invoked assumptions for ${\cal N}=4$ SYM, including BDS one-loop exponentiation of the splitting function and amplitude/Wilson-loop duality.

2606.08581 2026-06-09 math.PR 新提交

The Pile Process on a Cycle

环上的堆叠过程

Itai Benjamini, Eric Shellef

AI总结 研究环上粒子从低邻点向最低邻点移动的有限粒子系统,证明从单点初始配置的期望稳定时间至多为n^3的常数倍,确定性运输下界为n^2量级,模拟表明真实阶接近n^3。

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AI中文摘要

考虑一个有限粒子系统,其中每一步,一个粒子从一个具有较低邻点的顶点移动到高度最小的邻点。对于环C_n,从n个粒子集中在一个顶点而其他顶点无粒子的初始状态出发,我们证明期望稳定时间至多为n^3的常数倍。确定性运输下界为n^2量级。模拟表明真实阶应接近n^3。Chat GPT被用于重写2007年的笔记。

英文摘要

Consider a finite particle system in which, at each step, one particle from a vertex with a lower neighboring vertex moves to a neighboring vertex of minimum height. For the cycle C_n, started with n particles at one vertex and no particles elsewhere, we prove that the expected stabilization time is at most a constant multiple of n^3 The deterministic transportation lower bound is of order n^2. Simulations suggest that the true order should be near n^3. Chat GPT was used to reincarnate notes from 2007.

2606.08577 2026-06-09 cs.IR 新提交

When Should Queries Be Decomposed? A Stage-Aware Study of Query Decomposition for Multi-Condition Retrieval

何时应分解查询?面向多条件检索的查询分解的阶段感知研究

Bochao Yin, Xuan Lu, Zhengyu Qi, Xiaoyu Shen

AI总结 本文通过阶段感知实验发现,查询分解在初始检索阶段因语义稀释损害性能,但在重排序阶段通过细粒度约束验证显著提升效果,据此提出阶段感知分解框架,在初始检索保留整体查询,仅在重排序使用子查询,在MultiConIR和SSRB基准上一致提升组合查询的排序性能。

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AI中文摘要

多条件检索要求系统识别满足多个不同约束的文档,超越了单纯的主题相关性。尽管查询分解被广泛采用作为一种直观的补救措施,但其在不同检索流水线阶段的有效性仍未得到充分探索。在本文中,我们进行了一项阶段感知的实证研究,并揭示了一个鲜明的、阶段依赖的效应:初始检索中的分解由于语义稀释常常损害检索性能,但通过实现更细粒度的约束验证,显著改进了重排序。受这些见解的启发,我们提出了一个原则性的阶段感知分解框架,该框架在初始检索期间保留整体查询以保持全局语义上下文,而在重排序期间仅使用子查询进行细粒度约束匹配。在MultiConIR和SSRB基准上的广泛评估表明,我们的框架在多个检索和重排序模型上一致地改进了组合查询的排序性能。我们在https://github.com/EIT-NLP/Query-Decompose发布代码。

英文摘要

Multi-condition retrieval requires systems to identify documents that satisfy multiple distinct constraints, moving beyond mere topical relevance. While query decomposition is widely adopted as an intuitive remedy, its effectiveness across different retrieval pipeline stages remains underexplored. In this paper, we conduct a stage-aware empirical study and uncover a stark, stage-dependent effect: decomposition during initial retrieval frequently harms retrieval performance due to semantic dilution, yet substantially improves reranking by enabling more fine-grained constraint verification. Motivated by these insights, we propose a principled Stage-Aware Decomposition framework that retains the monolithic query during initial retrieval to preserve global semantic context, while employing sub-queries exclusively during reranking for fine-grained constraint matching. Extensive evaluations on the MultiConIR and SSRB benchmarks demonstrate that our framework consistently improves ranking performance for compositional queries across multiple retrieval and reranking models. We release our code at https://github.com/EIT-NLP/Query-Decompose.

2606.08576 2026-06-09 math.FA 新提交

Numerical radius of certain two-by-two block matrices

某些二乘二分块矩阵的数值半径

Hwa-Long Gau, Jia-Huo Hong, Chi-Kwong Li, Kuo-Zhong Wang

AI总结 研究形如T = [A B; 0 0]的算子的数值域和数值半径,得到改进的数值半径不等式,并刻画了当A为自伴对合时数值域为椭圆盘的条件,最后探讨了满足特定范数条件的矩阵与上述分块形式的联系。

Comments 28 pages

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AI中文摘要

我们研究形如 $T = \begin{pmatrix} A & B \\\\ 0 & 0 \end{pmatrix}$ 的算子的数值域 $W(T)$ 和数值半径 $w(T)$。我们证明 $W(T)$ 是一族 $2\times 2$ 矩阵 $T_x$ 的数值域的并集,这导致若干推论,包括 $w(T)$ 的改进不等式。对于 $A$ 是自伴对合的情形,我们刻画了 $W(T)$ 为椭圆盘的条件,并确定了所有酉算子 $U$ 下 $T_U = \begin{pmatrix} U^*AU & B \\\\ 0 & 0 \end{pmatrix}$ 的最小数值半径。最后,我们研究满足 $\|T^m x\| = \|T^m\| = \|T\|$(对某个单位向量 $x$ 和所有正整数 $m$)的矩阵 $T \in M_n$。这一分析将这些矩阵与前述分块形式联系起来,并给出了一个反例,反驳了如下猜想:若对所有 $k \ge 1$ 有 $\|T^k\| = \|T\|$,则矩阵的某次幂有一个直和项是幂等元的标量倍。

英文摘要

We investigate the numerical range $W(T)$ and numerical radius $w(T)$ of operators of the form $T = \begin{pmatrix} A & B \\ 0 & 0 \end{pmatrix}$. We show that $W(T)$ is the union of the numerical ranges of a family of $2\times 2$ matrices, $T_x$, leading to several consequences, including improved inequalities for $w(T)$. For cases where $A$ is a self-adjoint involution, we characterize the conditions under which $W(T)$ is an elliptical disk and determine the minimum numerical radius of $T_U = \begin{pmatrix} U^*AU & B \\ 0 & 0 \end{pmatrix}$ over all unitary operators $U$. Finally, we study matrices $T \in M_n$ satisfying $\|T^m x\| = \|T^m\| = \|T\|$ for a unit vector $x$ and all positive integers $m$. This analysis connects these matrices to the aforementioned block form and provides a counterexample to the conjecture that if $\|T^k\| = \|T\|$ for all $k \ge 1$, then some power of the matrix has a direct summand that is a scalar multiple of an idempotent.

2606.08575 2026-06-09 physics.flu-dyn 新提交

Rise regimes of freely rising droplets with a moderate viscosity ratio

中等粘度比自由上升液滴的上升状态

Pengyu Shi, Dirk Lucas, Jie Zhang, Éric Climent, Dominique Legendre

AI总结 通过数值模拟研究中等粘度比(μ*=0.62)的甲苯液滴在水中自由上升的动力学,揭示了从稳态垂直上升到混沌路径的丰富状态序列,并发现内部流动失稳是路径不稳定的核心机制。

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AI中文摘要

本文数值研究了中等液滴-流体粘度比$μ^\ast$下,浮力液滴在大量不混溶液体中自由上升的动力学。我们聚焦于在清洁水中上升的甲苯液滴,其$μ^\ast=0.62$,半径变化范围为$0.5\\,\text{mm}\leq R\leq3.0\\,\text{mm}$。在轴对称和完全三维构型下进行直接数值模拟。随着$R$增加,系统展现出丰富的上升状态序列。从具有轴对称扰动流的稳态垂直上升开始,首先经历与方位角模态$m=2$相关的内部流动失稳,导致双平面对称尾流和终端速度降低。随后是稳态倾斜状态,其中$m=1$模态也变得不稳定并与$m=2$模态共存。在更大半径下,路径再次接近垂直,然后进入$m=2$旋转波状态,其中尾流以近似恒定的角速度方位角漂移。对于更大的液滴,持续的形状振荡和涡脱落导致完全三维混沌路径。从有限振幅非对称状态初始化的模拟进一步揭示了多个多稳态尺寸范围,其中不同的终端状态取决于初始条件而共存。综合来看,这些发现表明中等粘度比液滴的路径不稳定性与气泡和固体颗粒有根本不同:在本文遇到的大多数状态中,轴对称性破坏在液滴内部启动,突出了内部流动失稳在塑造后续尾流结构、上升速度和液滴动力学中的核心作用。

英文摘要

The dynamics of buoyant droplets rising freely in a large body of an immiscible liquid is investigated numerically for a moderate drop-to-fluid viscosity ratio $μ^\ast$. We focus on toluene droplets rising in clean water, for which $μ^\ast=0.62$, and vary the radius over $0.5\,\text{mm}\leq R\leq3.0\,\text{mm}$. Direct numerical simulations are performed in imposed axisymmetric and fully three-dimensional configurations. As $R$ increases, the system displays a rich sequence of rise regimes. Starting from steady vertical rise with an axisymmetric disturbance flow, it first undergoes an internal flow instability associated with an azimuthal mode $m=2$, leading to a biplanar-symmetric wake and reduced terminal speed. This state is followed by a steady oblique regime, in which the $m=1$ mode also becomes unstable and coexists with the $m=2$ mode. At larger radii, the path becomes nearly vertical again before the flow enters an $m=2$ rotating-wave regime, where the wake drifts azimuthally at an approximately constant angular velocity. For still larger droplets, persistent shape oscillations and vortex shedding lead to fully three-dimensional chaotic paths. Simulations initialised from finite-amplitude asymmetric states further reveal several multistable size ranges, in which distinct terminal states coexist depending on the initial condition. Taken together, these findings show that the path instability of moderate-viscosity-ratio droplets differs fundamentally from that of bubbles and solid particles: in most regimes encountered here, axisymmetry breaking is initiated within the droplet, highlighting the central role of the internal flow instability in shaping the subsequent wake structure, rise speed and droplet dynamics.

2606.08570 2026-06-09 math.AG math.RT math.SG 新提交

Newton--Okounkov bodies of partial flag varieties via cluster algebras

部分旗簇的Newton--Okounkov体:通过簇代数

Yunhyung Cho, Myungho Kim, Yoosik Kim, Euiyong Park

AI总结 利用单胞上的簇结构构造部分旗簇中Schubert变体的Newton-Okounkov多面体,证明在无限型簇代数下存在无穷多互不等价的多面体,并应用于构造无穷多不同的单调拉格朗日环面。

Comments 45 pages, 11 figures

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AI中文摘要

我们利用单胞上的簇结构,构造了任意类型部分旗簇中Schubert变体的Newton--Okounkov多面体。当主导簇代数为无限型时,我们证明:对于单连部分旗簇上的任意极丰沛齐次线丛,由此产生的Newton--Okounkov多面体族包含无穷多个在整仿射变换下互不等价的多面体。作为对辛几何的应用,我们在一大类单连部分旗簇中构造了无穷多个不同的单调拉格朗日环面。

英文摘要

We construct Newton--Okounkov polytopes of Schubert varieties in partial flag varieties of arbitrary type using the cluster structure on a unipotent cell. When the governing cluster algebra is of infinite type, we prove that for any very ample homogeneous line bundle over a simply laced partial flag variety, the resulting family of Newton--Okounkov polytopes contains infinitely many pairwise nonequivalent polytopes up to integral affine transformation. As an application to symplectic geometry, we construct infinitely many distinct monotone Lagrangian tori in a broad class of simply laced partial flag varieties.

2606.08569 2026-06-09 q-fin.PM 新提交

Stock Investment: The p-index Approach

股票投资:p-指数方法

Xinzhao Xie, Bopei Nie, Kuo-Ping Chang

AI总结 利用欧式看跌期权构建p-指数风险度量,评估中国上证50指数和美国标普500指数在2018-2023年间的投资策略表现,发现p-指数策略在不同市场条件下优于传统方法。

Comments arXiv admin note: text overlap with arXiv:2510.11074

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AI中文摘要

本文利用欧式看跌期权构建了p-指数风险度量,以评估2018-2023年间中国上证50指数和美国标普500指数不同投资策略的表现。p-指数衡量每保险一美元所需的保险费,以保证资产在指定未来日期至少达到δ收益率。研究发现,采用公平价格策略时,一周和一个月持有期能获得更高收益;在七个经济板块中,材料板块股票的年化收益率最高:一周持有期11.04%,两周持有期11.93%,一个月持有期10.18%。采用一周持有期的动量和反转策略中,p-比率有效反转策略产生了最高的年化收益率(9.97%),其次是p-指数无效动量策略(9.01%)和p-指数有效反转策略(6.48%);使用p-指数的MCIRS方法始终比基于beta的方法获得更高收益;有效(跑赢)股票未能维持其动量,而无效(跑输)股票未表现出均值回归。还发现,p-指数有效反转策略在低情绪(低成交量)状态下表现更优,而p-指数无效动量策略在高情绪(高成交量)时期表现更优。对于2018-2023年间美国标普500指数的500只股票,发现有效股票维持了动量,而无效股票表现出均值回归。p-指数有效动量策略产生了最高的年化收益率(3.69%),其次是p-比率无效反转策略(3.67%)和beta有效动量策略(3.48%)。

英文摘要

This paper has used European put option to construct the p-index risk measure to evaluate the performance of different investment strategies in China's SSE 50 index and the US SP500 index during 2018-2023. The p-index measures the insurance fee for each insured dollar to guarantee that the asset achieves at least a delta rate of return on a specified future date. It is found that with the fair price strategy, one-week and one-month holding periods can earn more, and among seven economic sectors, materials sector stocks generated highest annualized rates of return: 11.04% (one-week period), 11.93% (two-week period) and 10.18% (one-month period). With momentum and contrarian strategies of one-week holding period, the p-ratio-efficient-contrarian strategy produced the highest annualized rate of return (9.97%), followed by the p-index-inefficient-momentum strategy (9.01%) and the p-index-efficient-contrarian strategy (6.48%), the MCIRS method employing the p-index consistently delivered higher returns than its beta-based approach, and efficient (outperforming) stocks failed to sustain their momentum while inefficient (underperforming) stocks exhibited no mean reversion. It is also found that the p-index-efficient-contrarian strategy outperformed in low-sentiment (low-volume) regimes, while the p-index-inefficient-momentum strategy outperformed during high-sentiment (high-volume) periods. For the five hundred stocks of the US S&P 500 index during 2018-2023, it is found that efficient stocks sustained their momentum while inefficient stocks exhibited mean reversion. The p-index-efficient-momentum strategy produced the highest annualized rate of return (3.69%), followed by the p-ratio-inefficient-contrarian strategy (3.67%) and the beta-efficient-momentum strategy (3.48%).

2606.08568 2026-06-09 cs.CY 新提交

Regulating the AI Tutor: Intentions, Help-Seeking, and Self-Regulated Learning in Adolescent GenAI Use

调控AI导师:青少年使用生成式AI时的意图、求助行为与自我调节学习

Rania Abdelghani, Peter Kaiser, Kou Murayama

AI总结 研究通过98名九年级学生的对话数据,分析青少年使用生成式AI学习时的自我调节学习和求助行为,发现学生主要进行工具性请求而缺乏监控评估,且后测成绩显著下降。

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AI中文摘要

生成式AI工具现已成为青少年常见的学习伴侣,但他们在真实学习任务中如何调控其使用仍知之甚少。自我调节学习(SRL)和高层次求助(HS)通常被提议作为防止被动或捷径导向使用的保障,但大多数实证研究关注的是总体学习成果,而非AI支持学习过程中的这些实时过程。这项进行中的研究考察了来自三所德国文理中学的98名九年级学生的开放式对话数据,他们使用基于网络的Mistral-Large导师为考试准备一项课程对齐的数学技能。除了聊天记录(1616轮次;808个学生轮次),我们还收集了前后测领域知识、聊天前的学习需求以及自我报告的认知负荷。我们提出了一个轮次级编码手册,结合了理论驱动的SRL和HS构念与两个LLM特定的归纳编码(对AI的能动性;认知警觉性),并报告了初步的AI编码结果。尽管学生在聊天前 overwhelmingly 选择了支架式支持,但他们的互动以工具性请求为主,几乎没有明确的监控或评估。后测成绩显著低于前测,且在控制先前知识后,更高的外在认知负荷预测了更低的后测成绩。我们讨论了这些模式如何支持人机混合分析互动模式,并为更具能动性和认知主动性的生成式AI使用提供支架。

英文摘要

Generative AI (GenAI) tools are now common learning companions for adolescents, yet how they regulate their use during authentic learning tasks remains poorly understood. Self-regulated learning (SRL) and high-level help-seeking (HS) are commonly proposed as safeguards against passive or shortcut-oriented use, but most empirical studies focus on aggregate learning outcomes rather than these moment-to-moment processes during AI-supported learning. This work-in-progress examines open-ended conversational data from 98 Grade-9 students across three German Gymnasium schools, who used a web-based Mistral-Large tutor to prepare a curriculum-aligned mathematics skill before an exam. Alongside chat logs (1,616 turns; 808 student turns), we collected pre-post domain knowledge, pre-chat learning needs, and self-reported cognitive load. We propose a turn-level codebook combining theory-driven SRL and HS constructs with two LLM-specific inductive codes (agency over the AI; epistemic vigilance), and report preliminary AI-coded results. Although students overwhelmingly selected scaffolded support before the chat, their interactions were dominated by instrumental requests with almost no explicit monitoring or evaluation. Post-test performance was significantly lower than pre-test, and higher extraneous cognitive load predicted lower post-test scores after controlling for prior knowledge. We discuss how these patterns can support hybrid human-AI analysis of interaction patterns and inform scaffolds for more agentic and epistemically proactive GenAI use.

2606.08567 2026-06-09 cond-mat.mtrl-sci physics.app-ph 新提交

V-Doped Niobate Nanosheets for Enhanced Photocatalytic Activity

V掺杂铌酸盐纳米片增强光催化活性

M. Tuğrul Avcu, Uğur Ünal

AI总结 通过固相反应、质子化和剥离制备V掺杂Ca2Nb3-xVxO10-纳米片,V掺杂减小带隙(从3.54 eV降至2.60-2.88 eV),最佳掺杂(x=0.3)的产氢速率达11.3 mmol/g/h,是未掺杂的4.7倍。

Comments Main Paper: 6 pages, 5 figures, 1 table. Supporting Information: 4 pages, 5 figures

详情
AI中文摘要

通过固相反应、质子化和四丁基铵离子剥离制备了V掺杂的[Ca$_{2}$Nb$_{3-x}$V$_{x}$O$_{10}$]$^{-}$(x = 0, 0.15, 0.3, 0.6, 0.75)纳米片。二维纳米片因其小厚度(减少电子-空穴复合)、大表面积(增加光催化位点)以及V掺杂导致的带隙减小,具有改善的光催化活性。V掺杂使未掺杂纳米片的宽带隙3.54 eV降低到2.60-2.88 eV范围。在析氢反应中使用10 vol%甲醇作为空穴牺牲剂,并在纳米片上沉积3 wt% Pt作为助催化剂。在全光谱Xe灯下,[Ca$_{2}$Nb$_{2.7}$V$_{0.3}$O$_{10}$]$^{-}$的H$_{2}$产率是未掺杂纳米片的4.7倍,产率为11.3 mmol/g/h;负载Pt助催化剂的[Ca$_{2}$Nb$_{2.7}$V$_{0.3}$O$_{10}$]$^{-}$的H$_{2}$产率是负载Pt的未掺杂纳米片的2.9倍。

英文摘要

V-doped [Ca$_{2}$Nb$_{3-x}$V$_{x}$O$_{10}$]$^{-}$ (x = 0, 0.15, 0.3, 0.6, 0.75) nanosheets were produced by solid state reaction followed by protonation and exfoliation by tetrabutylammonium ions. 2D nanosheets have improved photocatalytic activity due to their small thickness that reduces electron-hole recombination, larger surface area that increases photocatalytic sites, and decreased band gap from added V. V-doping has caused the wide band gap of 3.54 eV of undoped nanosheets to decrease to 2.60-2.88 eV range. 10 vol% methanol was used as a hole scavenger in the hydrogen evolution reactions, and 3 wt% Pt was deposited on nanosheets as a co-catalyst. Under a full-spectrum Xe light, [Ca$_{2}$Nb$_{2.7}$V$_{0.3}$O$_{10}$]$^{-}$ has produced 4.7 times the H$_{2}$ yield as undoped nanosheets with a 11.3 mmol/g/h production rate, [Ca$_{2}$Nb$_{2.7}$V$_{0.3}$O$_{10}$]$^{-}$ with Pt co-catalyst has produced 2.9 times the H$_{2}$ yield as undoped Pt-loaded nanosheets.

2606.08561 2026-06-09 quant-ph 新提交

A five-qubit 1-resistant graph state and stabilizer marginal certificates

五量子比特1-抵抗图态与稳定子边际证书

Zicheng Han, Wanchen Zhang, Xiande Zhang

AI总结 本文通过五环图态|C5⟩解决了五量子比特1-抵抗纯态的存在性问题,并发展了稳定子子群方法用于验证图态的m-抵抗性,给出了五至七顶点图态的分类。

Comments 10 pages, 1 figure, 1 table

详情
AI中文摘要

我们在稳定子和图态的框架下研究粒子损失抵抗纠缠。如果一个纯态在损失任意m个粒子后仍然纠缠,而在损失任意m+1个粒子后变得完全可分,则称其为m-抵抗的。先前未解决的最小量子比特情况是五量子比特1-抵抗纯态的存在性,本文通过五环图态|C5⟩解决了该问题。我们还发展了一种稳定子子群方法,用于验证图态的m-抵抗性,该方法利用局部稳定子来证明完全可分性,并利用精确的负部分转置(NPT)见证者来证明纠缠性。将此方法应用于所有与五、六、七顶点上的非同构图相关的图态,我们得到了图态在局部Clifford等价下的分类,这也分类了稳定子态在局部Clifford等价下的类别。因此,五量子比特1-抵抗稳定子态恰好是C5的局部Clifford类。六量子比特2-抵抗稳定子态存在于三个不同的局部Clifford类中,而七量子比特稳定子态对于任何非零允许的m都不是m-抵抗的。最后,我们证明对于N≥7,环图态|C_N⟩对于任何0≤m≤N-2都不是m-抵抗的。

英文摘要

We study particle-loss resistant entanglement within the framework of stabilizer and graph states. A pure state is \(m\)-resistant if it remains entangled after the loss of any \(m\) particles and becomes fully separable after the loss of any \(m+1\) particles. The smallest previously unresolved qubit case was the existence of a five-qubit \(1\)-resistant pure state, which is resolved here by the five-cycle graph state \(\ket{C_5}\). A stabilizer-subgroup method is also developed for verifying \(m\)-resistance in graph states, using local stabilizers to certify full separability and exact negative partial transpose~(NPT) witnesses to certify entanglement. Applying this to all graph states associated with non-isomorphic graphs on five, six, and seven vertices, we obtain a graph state classification up to local Clifford equivalence, which also classifies stabilizer states up to local Clifford equivalence. Thus, the five-qubit \(1\)-resistant stabilizer states are exactly the local Clifford class of \(C_5\). Six-qubit \(2\)-resistant stabilizer states exist in three distinct local Clifford classes, whereas no seven-qubit stabilizer state is \(m\)-resistant for any nonzero admissible \(m\). Finally, we prove that the cycle graph states \(\ket{C_N}\) with \(N\ge 7\) are not \(m\)-resistant for any \(0\le m\le N-2\).

2606.08560 2026-06-09 stat.ME econ.EM stat.ML 新提交

CP-factorization for high dimensional tensor time series and double projection iterations

高维张量时间序列的CP分解与双投影迭代

Jinyuan Chang, Guanglin Huang, Qiwei Yao, Long Yu

AI总结 采用规范多元分解(CP)建模高维张量时间序列,提出基于序列依赖结构的单次估计方法,并引入双投影迭代算法降低估计误差,理论证明了收敛速度与渐近分布。

详情
AI中文摘要

我们采用规范多元分解(CP)来建模高维张量时间序列。主要目标是识别和估计CP分解中的因子载荷。我们提出了一种基于数据序列依赖结构构建矩阵的标准特征分析的单次估计程序。在因子载荷向量线性独立的一般设定下,建立了所提估计量的渐近性质,允许因子相关且因子载荷向量不近似正交。该程序适应因子载荷向量的稀疏性,容纳弱因子,并在广泛场景中表现出强性能。为了进一步减少估计误差,我们还引入了一种基于新颖双投影方法的迭代算法。我们从理论上证明了迭代估计量改进的收敛速度,并推导了相关的极限分布。还提供了一致渐近方差估计量,这在相关推断问题中起关键作用。所有结果通过大量模拟和两个实际数据应用得到验证。

英文摘要

We adopt the canonical polyadic (CP) decomposition to model high-dimensional tensor time series. Our primary goal is to identify and estimate the factor loadings in the CP decomposition. We propose a one-pass estimation procedure through standard eigen-analysis for a matrix constructed based on the serial dependence structure of the data. The asymptotic properties of the proposed estimator are established under a general setting as long as the factor loading vectors are linearly independent, allowing the factors to be correlated and the factor loading vectors to be not nearly orthogonal. The procedure adapts to the sparsity of the factor loading vectors, accommodates weak factors, and demonstrates strong performance across a wide range of scenarios. To further reduce estimation errors, we also introduce an iterative algorithm based on a novel double projection approach. We theoretically justify the improved convergence rate of the iterative estimator, and derive the associated limiting distribution. A consistent estimator of the asymptotic variance is also provided, which plays a key role in the related inference problems. All results are validated through extensive simulations and two real data applications.