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2606.08910 2026-06-09 astro-ph.HE gr-qc 新提交

Relativistic Thermal Emission from Accretion Disks in Kerr-MOG Spacetimes

Kerr-MOG时空中吸积盘的相对论热辐射

Cheng Liu, Xu-fan Hu, Yosuke Mizuno, Tao Zhu

AI总结 研究标量-张量-矢量引力(MOG)中矢量场对Kerr-MOG黑洞吸积盘热连续谱的影响,发现第五种力使ISCO外移、峰值温度降低并软化热谱,且与自旋降低效应类似,需结合铁线反射谱区分。

Comments 16pages, 11 figures. Accepted for publication in ApJ

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AI中文摘要

在标量-张量-矢量引力(STVG,也称为MOG)中,一个质量矢量场$ϕ_μ$产生排斥性的第五种力,使旋转黑洞具有引力电荷$Q \propto \sqrtα\\,M$,通过单个变形参数$α$修改近视界几何。我们研究这种矢量场耦合如何印迹在Kerr-MOG黑洞的几何薄、光学厚吸积盘的热连续谱发射上。通过重新推导Kerr-MOG时空的最内稳定圆轨道(ISCO)、Novikov-Thorne辐射通量、相对论能量偏移和零测地线结构,我们使用专用的\textsc{xspec}谱模型(\texttt{kmspec})计算了广泛自旋、倾角和第五种力强度下的完全相对论性盘谱。我们发现,第五种力电荷将ISCO向外推,降低峰值盘温度,并系统性地使热连续谱相对于相同自旋的Kerr黑洞对应物变软,且在高观测倾角下偏差放大。由此产生的谱修改密切模仿纯Kerr黑洞框架中自旋的降低,表明来自例如铁线反射谱的独立自旋测量对于区分矢量场贡献是不可或缺的。当$α= 0$时,所有结果恢复标准Kerr黑洞预测,并且该模型通过独立解析和数值基准验证达到机器精度。应用于LMC X-1的69.6 ks \textit{XMM-Newton}观测,在90%置信度下得到$α< 0.044$,与Kerr度规和广义相对论一致。

英文摘要

In Scalar-Tensor-Vector Gravity (STVG, also known as MOG), a massive vector field $ϕ_μ$ generates a repulsive fifth force that endows rotating black holes with a gravitational charge $Q \propto \sqrtα\,M$, modifying the near-horizon geometry through a single deformation parameter $α$. We investigate how this vector-field coupling imprints itself on the thermal continuum emission of geometrically thin, optically thick accretion disks in the Kerr-MOG black hole. By re-deriving the innermost stable circular orbit (ISCO), the Novikov-Thorne radiative flux, the relativistic energy shift, and the null geodesic structure for the Kerr-MOG spacetime, we compute fully relativistic disk spectra across a broad range of spins, inclinations, and fifth-force strengths using a dedicated \textsc{xspec} spectral model (\texttt{kmspec}). We find that the fifth-force charge pushes the ISCO outward, lowers the peak disk temperature, and systematically softens the thermal continuum relative to its Kerr black hole counterpart at the same spin, with the deviation amplified at high observer inclinations. The resulting spectral modification closely mimics a reduction of spin in the pure Kerr black hole framework, indicating that independent spin measurements from, e.g., iron-line reflection spectroscopy are indispensable for disentangling the vector-field contribution. All results recover the standard Kerr black hole predictions when $α= 0$, and the model is validated against independent analytic and numerical benchmarks to machine precision. Application to a 69.6~ks \textit{XMM-Newton} observation of LMC~X-1 yields $α< 0.044$ at 90\% confidence, consistent with the Kerr metric and general relativity.

2606.08909 2026-06-09 math.AG 新提交

Elliptic orbifold lines and integrable hierarchies

椭圆轨道线与可积层次

Todor Milanov

AI总结 本文证明椭圆轨道线P^1_{3,3,3}、P^1_{2,4,4}和P^1_{2,3,6}的Gromov-Witten不变量满足Hirota二次方程系统,是P^1的Toda猜想的类比,并引入主符号可用椭圆theta函数表示的新的双线性算子。

Comments 77 pages, 1 figure

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AI中文摘要

我们证明了椭圆轨道线 $\mathbf{P}^1_{3,3,3}$、$\mathbf{P}^1_{2,4,4}$ 和 $\mathbf{P}^1_{2,3,6}$ 的 Gromov--Witten 不变量满足某个 Hirota 二次(或双线性)方程系统。我们的结果是 $\mathbf{P}^1$ 的 Gromov-Witten 理论中所谓的 Toda 猜想的类比,更准确地说,是其非扩展版本。我们构造中的一个新特征是某个双线性算子,其主符号可以用椭圆 theta 函数表示。

英文摘要

We prove that the Gromov--Witten invariants of the elliptic orbifold lines $\mathbf{P}^1_{3,3,3}$, $\mathbf{P}^1_{2,4,4}$, and $\mathbf{P}^1_{2,3,6}$ satisfy a certain system of Hirota Quadratic (or Bilinear) Equations. Our result is the analogue of the so-called Toda conjecture in the Gromov-Witten theory of $\mathbf{P}^1$ or more precisely its non-extended version. A new feature in our constructions is a certain bilinear operator whose principal symbol can be expressed in terms of elliptic theta functions.

2606.08905 2026-06-09 quant-ph 新提交

Impact of the Unruh effect on the estimation precision of Gaussian channel parameters

Unruh效应对高斯信道参数估计精度的影响

Shoukang Chang, Yawen Tang, Wei Ye, Shao-Ming Fei, Zunlue Zhu, Xingdong Zhao

AI总结 研究Unruh效应对高斯信道参数估计精度的影响,发现其显著降低单参数和双参数估计精度,并证明量子Cramér-Rao界是渐近可达的精度极限,零差测量在高加速或大热均值时接近最优。

Comments 22 pages, 21 figures

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Journal ref
Physical Review A 113, 062609 (2026)
AI中文摘要

高斯量子信道构成了描述高斯量子态动力学的一个关键物理框架。大量学术关注已投入到与高斯信道相关的参数估计中。然而,以往研究主要关注惯性系内的参数估计,非惯性场景,特别是在Unruh效应的背景下,仍然很大程度上未被探索。在本文中,我们分析了Unruh效应对高斯信道参数估计精度的影响,特别关注热衰减器和热放大器信道。我们的发现表明,当使用输入相干态和压缩真空态时,Unruh效应显著降低了高斯信道参数的单参数估计精度。对于双参数估计,我们进一步证明量子Cramér-Rao界是一个渐近可达的精度极限。与单参数情况一致,Unruh效应对双参数估计精度产生不利影响。值得注意的是,在高加速或大热均值数的极限下,零差测量对于单参数和双参数估计都是接近最优的。这些结果为在相对论背景下推进量子参数估计提供了关键的理论见解和实际指导。

英文摘要

Gaussian quantum channels constitute a pivotal physical framework for characterizing the dynamics of Gaussian quantum states. Extensive scholarly attention has been devoted to the estimation of parameters associated with Gaussian channels. However, while previous research has predominantly focused on parameter estimation within inertial frames, the noninertial scenario, particularly in the context of the Unruh effect, remains largely unexplored. In this paper, we analyze the impact of the Unruh effect on the estimation precision of Gaussian channel parameters, with a specific focus on thermal attenuator and thermal amplifier channels. Our findings reveal that the Unruh effect significantly degrades the precision of single-parameter estimation for Gaussian channel parameters when employing both the input coherent state and squeezed vacuum state. For the two-parameter estimation, we further demonstrate that the quantum Cramér-Rao bound serves as an asymptotically achievable precision limit. Consistent with the single-parameter case, the Unruh effect exerts a detrimental impact on the precision of two-parameter estimation. Notably, heterodyne measurement is near-optimal for both single- and two-parameter estimation in the limit of high acceleration or large thermal mean numbers. These results provide crucial theoretical insights and practical guidance for advancing quantum parameter estimation in a relativistic context.

2606.08902 2026-06-09 cs.LO econ.TH 新提交

A Kernel-Clean Lean Mechanization of Classical Lottery in Action and the Wakker--Debreu--Koopmans Representation Layer

行动中的经典彩票与Wakker-Debreu-Koopmans表示层的核清洁Lean机械化

Jingyuan Li, Ilia Tsetlin, Fan Wang

AI总结 本文用Lean 4/Mathlib形式化了经典彩票与WDK层的加性表示理论,核心结果是机器验证了交叉对Thomsen/双消去条件不可从序数公理推导,并提供了显式反模型。

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AI中文摘要

我们提出了行动中的经典彩票及其依赖的Wakker-Debreu-Koopmans (WDK)层背后的加性表示理论的Lean 4/Mathlib形式化。我们的核心结果是机器验证的证明,即交叉对Thomsen/双消去(六边形)条件不能从加性联合测量的序数公理(弱序、受限可解性、阿基米德条件和权衡一致性)推导出来。我们展示了一个显式的验证反模型(additiveRealBoolPref),它满足所有序数公理但违反交叉对条件,其中每个严格标准序列都是算术级数,因此非稠密。围绕这一边界,我们机械化完整的可推导构造:来自可分性的连续Debreu/Eilenberg效用、标准序列网格、基于连通性的二分法以及全局加性粘合。所有公开定理都是无sorry的条件包装器,基于这一单个不可约的结构输入。该开发是核清洁的,仅依赖于标准Lean基础(propext、Classical.choice、Quot.sound)。配套文件ClassicalLotteryInAction.lean形式化了局部经典彩票构造、平均效用结果、匹配频率引理以及《管理科学》论文使用的模糊态度陈述。这为加性联合测量能证明什么和必须假设什么划出了一条精确的、机器认证的界限。

英文摘要

We present a Lean 4/Mathlib formalization of the additive representation theory behind Classical Lottery in Action and the Wakker-Debreu-Koopmans (WDK) layer it relies on. Our central result is a machine-checked proof that the cross-pair Thomsen / double-cancellation (hexagon) condition is irreducible from the ordinal axioms of additive conjoint measurement (weak order, restricted solvability, Archimedean condition, and tradeoff consistency). We exhibit an explicit verified counter-model (additiveRealBoolPref) satisfying all ordinal axioms yet failing the cross-pair condition, with every strict standard sequence being an arithmetic progression and hence non-dense. Around this boundary we mechanize the full derivable construction: continuous Debreu/Eilenberg utility from separability, standard-sequence grids, bisection methods from connectedness, and global additive gluing. All public theorems are sorry-free conditional wrappers over this single irreducible structural input. The development is kernel-clean, depending only on standard Lean foundations (propext, Classical.choice, Quot.sound). The companion file ClassicalLotteryInAction.lean formalizes local classical-lottery constructions, average-utility results, matching-frequency lemmas, and ambiguity-attitude statements used by the Management Science paper. This draws a precise, machine-certified line between what additive conjoint measurement can prove and what it must assume.

2606.08901 2026-06-09 math.DS 新提交

One-dimensional first return maps for the two-dimensional border-collision normal form with a zero determinant

零行列式二维边界碰撞标准型的一维首次返回映射

David J. W. Simpson

AI总结 研究零行列式二维边界碰撞标准型的一维首次返回映射,通过Farey序列刻画映射结构,并证明参数空间中混沌到准周期或锁模的分岔。

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AI中文摘要

二维边界碰撞标准型是一个四参数连续分段线性映射族。当该形式具有零行列式时,其所有非线性动力学都由一维首次返回映射捕获。首次返回映射是不连续且分段线性的,其中映射的每一段对应于恒定的返回时间。我们证明,当标准型具有排斥焦点不动点时,首次返回映射的配置由有理旋转数决定,其中返回时间集合和映射段的顺序由该数的左、右Farey父序列的分母给出。该结果通过刻画由切换流形原像形成的多边形,并利用Farey网上的归纳论证证明。参数空间中配置变化的几个曲面是从混沌到准周期或锁模动力学的分岔。

英文摘要

The two-dimensional border-collision normal form is a four-parameter family of continuous, piecewise-linear maps. When this form has a zero determinant, all of its nonlinear dynamics are captured a one-dimensional first return map. The first return map is discontinuous and piecewise-linear, where each piece of the map corresponds to a constant return time. We show that when the normal form has a repelling focus fixed point, the configuration of the first return map is dictated by a rational rotation number whereby the set of return times and ordering of the pieces of the map are given by the denominators of the left and right sequences of Farey parents of this number. The result is proved by characterising polygons formed from preimages of the switching manifold, and employing an inductive argument on the Farey web. Several surfaces in parameter space where the configuration changes are bifurcations from chaotic to quasiperiodic or mode-locked dynamics.

2606.08900 2026-06-09 math-ph math.MP 新提交

Symmetry Regularization of 1D Generalized Coulomb Problems

一维广义库仑问题的对称正则化

Zhanqiang Bai, Junwei Ma, Guowu Meng

AI总结 针对一维广义库仑问题族,构造了两个显式酉交织子,将希尔伯特空间的能量定号部分与SL(2,R)的酉最低权表示酉等同。

Comments 14 pages

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AI中文摘要

对于一维广义库仑问题——该族包括马-孟-肖 \cite{MMX2025} 的一维广义开普勒问题的量子化——我们构造了两个显式酉交织子 $\hat{\iota}_{\pm}$,它们是 \cite{MMX2025} 中经典对称正则化映射 $\iota_{\pm}$ 的量子类似物,将希尔伯特空间 $L^{2}(\mathbb{R}_{>0},\mathrm{d}q)$ 的每个 $H_{\kappa}$-能量定号部分与 $\widetilde{\mathrm{SL}}(2,\mathbb{R})$ 的酉最低权表示酉等同。

英文摘要

For the 1D generalized Coulomb problems--a family that includes the quantizations of the 1D generalized Kepler problems of Ma-Meng-Xiao \cite{MMX2025}--we construct two explicit unitary intertwiners $\hatι_{\pm}$, the quantum analogs of the classical symmetry regularization maps $ι_{\pm}$ of \cite{MMX2025}, that unitarily identify each $H_κ$-energy-definite portion of the Hilbert space $L^{2}(\mathbb{R}_{>0},\mathrm{d}q)$ with a unitary lowest-weight representation of $\widetilde{\mathrm{SL}}(2,\mathbb{R})$.

2606.08899 2026-06-09 astro-ph.CO astro-ph.GA astro-ph.HE 新提交

Mock Catalogs of Strongly Lensed Gravitational Waves via a Halo Model Approach with Space-borne Detectors

通过晕模型方法模拟空间探测器强引力透镜引力波的模拟星表

Mingqi Sun, Kai Liao, Youkai Li, Tonghua Liu, Hengyu Wu, Shaoqi Hou, Tao Yang, Xilong Fan, Marek Biesiada

AI总结 基于晕模型方法,构建空间探测器(LISA和DECIGO)强引力透镜引力波事件的模拟星表,预测透镜事件数量和概率,并指出信号重叠对信噪比估计和事件识别的影响。

Comments 18 pages, 13 figures, 10 tables

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AI中文摘要

未来的空间引力波(GW)探测器,如LISA和DECIGO,预计将探测到大量GW事件,其中一部分可能被 intervening 星系或星系团强透镜。在这项工作中,我们开发了一个全面的框架来模拟空间探测器背景下的强透镜GW。基于源种群和透镜分布的 realistic 天体物理模型,我们构建了透镜GW事件的模拟星表,称为 \textbf{GW-LMC-Space}。我们的结果表明,对于四年的LISA观测,透镜事件的预期数量范围从$0$到$131$,取决于所采用的大质量黑洞双星(MBHBs)的形成模型。相应的MBHBs透镜概率可达$\sim 0.3\%$。对于DECIGO,我们发现一年观测中透镜事件的数量预计在$0$--$44$范围内,对于恒星质量黑洞双星(BBHs)、双中子星(BNSs)和中子星-黑洞双星(NSBHs),透镜概率约为$\sim 0.15\%$。我们进一步表明,透镜信号的重叠是空间探测器的常见特征,这会显著影响信噪比(SNR)估计和事件识别。这些结果强调了在未来的空间GW观测中分析强透镜GW事件时考虑信号重叠的重要性。

英文摘要

Future space-borne gravitational-wave (GW) detectors, such as LISA and DECIGO, are expected to detect a large number of GW events, a fraction of which may be strongly lensed by intervening galaxies or galaxy clusters. In this work, we develop a comprehensive framework to simulate strongly lensed GWs in the context of space-borne detectors. Based on realistic astrophysical models for both the source population and the lens distribution, we construct mock catalogs of lensed GW events, referred to as \textbf{GW-LMC-Space}. Our results show that, for a four-year LISA observation, the expected number of lensed events ranges from $0$ to $131$, depending on the adopted formation model of massive black hole binaries (MBHBs). The corresponding lensing probability for MBHBs can reach up to $\sim 0.3\%$. For DECIGO, we find that the number of lensed events in a one-year observation is expected to lie in the range of $0$--$44$, with a lensing probability of $\sim 0.15\%$ for stellar-mass binary black holes (BBHs), binary neutron stars (BNSs), and neutron star--black hole binaries (NSBHs). We further show that the overlap of lensed signals is a common feature in space-borne detectors, which can significantly affect both the signal-to-noise ratio (SNR) estimation and event identification. These results highlight the importance of accounting for signal overlap in the analysis of strongly lensed GW events in future space-borne GW observations.

2606.08895 2026-06-09 cs.IT math.IT math.ST stat.TH 新提交

Optimal Regret Exponents for Bayesian Statistical Decision Problems

贝叶斯统计决策问题的最优遗憾指数

Hyun-Young Park, Si-Hyeon Lee

AI总结 研究有限状态有限动作贝叶斯统计决策问题,通过最小化不相容状态子集上的多元Chernoff信息,给出了任意损失函数下最优遗憾的精确指数,并首次得到列表假设检验的精确指数。

Comments 5 pages. This work has been submitted to the IEEE for possible publication

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AI中文摘要

我们研究有限状态有限动作的贝叶斯统计决策问题。尽管对于包括假设检验和假设排除在内的几种特殊情况,已知精确的错误指数刻画,但一般决策问题中最优贝叶斯遗憾的渐近行为在很大程度上是未知的。在本文中,我们证明最优遗憾总是以指数速度衰减,并刻画了任意损失函数下的精确指数。该指数由最小不相容状态子集上的多元Chernoff信息给出,其中不相容子集是指没有单个动作对该子集中所有状态都是最优的状态集合。我们的结果恢复了对称多元假设检验的经典成对最小Chernoff指数和假设排除的多元Chernoff指数,同时,据我们所知,首次给出了列表假设检验的精确指数刻画。

英文摘要

We study finite-state finite-action Bayesian statistical decision problems. While exact error-exponent characterizations are known for several special cases, including hypothesis testing and hypothesis exclusion, the asymptotic behavior of the optimal Bayes regret is largely unknown for general decision problems. In this paper, we show that the optimal regret always decays exponentially fast and characterize its exact exponent for arbitrary loss functions. The exponent is given by the minimum multivariate Chernoff information over the minimal incompatible subsets of states, where an incompatible subset is a collection of states for which no single action is optimal for all states in the subset. Our result recovers the classical pairwise-minimum Chernoff exponent for symmetric multiple hypothesis testing and the multivariate Chernoff exponent for hypothesis exclusion, while also yielding, to the best of our knowledge, the first exact exponent characterization for list hypothesis testing.

2606.08891 2026-06-09 cs.AR cs.ET 新提交

PALUTE: Processing-In-Memory Acceleration via Lookup Table for Edge LLM Inference

PALUTE: 基于查找表的处理-内存加速用于边缘LLM推理

Runyang Tian, Yanru Chen, Weihong Xu, Tajana Šimunić Rosing

AI总结 提出PALUTE,一种基于查找表的3D DRAM处理-内存加速器,通过垂直组织实现高并行度,降低面积开销,在0.16W功耗下达到1264 TPS吞吐量,能效比CHIME提升12.8倍。

Comments ISLPED 2026 IEEE/ACM International Symposium on Low Power Electronics and Design

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AI中文摘要

大型语言模型越来越多地部署在功率和面积预算紧张的边缘设备上。虽然混合精度GEMM降低了算术复杂度,但量化推理通常受反量化和非线性算子主导。基于查找表(LUT)的方法通过预计算输出并用表查找替代重复算术来缓解这些成本,但现有设计存在显著的容量和查找延迟开销。本文提出PALUTE,一种基于LUT的处理-内存加速器,构建在单片3D DRAM上,用于高效的边缘LLM推理。PALUTE支持DRAM内LUT查询,利用M3D DRAM内存阵列瓦片的垂直组织实现高并行度和低面积开销。近内存LUT生成器支持GEMM和逐元素一元非线性算子的低延迟LUT生成,而系统级分层和调度策略最小化了跨内存层的数据移动。使用周期精确仿真和RTL综合的评估表明,PALUTE在0.16W功耗下实现了1264 TPS的端到端吞吐量,能效比CHIME提升12.8倍,比FIGLUT提升1.6倍,在W4A4配置下Qwen3-4B模型上面积效率比PIMPAL提升2.0倍。

英文摘要

Large language models are increasingly deployed on edge devices with tight power and area budgets. While mixed-precision GEMM reduces arithmetic complexity, quantized inference is often dominated by dequantization and nonlinear operators. Lookup Table (LUT)-based method mitigates these costs by precomputing outputs and replacing repeated arithmetic with table lookups, but existing designs incur significant capacity and lookup-latency overheads. This paper presents PALUTE, a LUT-based Processing-In-Memory accelerator built on Monolithic 3D DRAM for efficient edge LLM inference. PALUTE enables in-DRAM LUT queries that exploit the vertical organization of M3D DRAM memory array tiles to achieve high parallelism with low area overhead. A near-memory LUT generator supports low-latency LUT generation for both GEMM and element-wise unary nonlinear operators, while a system-level tiering and scheduling strategy minimizes data movement across memory tiers. Evaluation using cycle-accurate simulation and RTL synthesis shows that PALUTE achieves 1,264 TPS end-to-end throughput at 0.16 W, improving energy efficiency by 12.8$\times$ over CHIME and 1.6$\times$ over FIGLUT, improving area efficiency by 2.0$\times$ over PIMPAL under W4A4 across Qwen3-4B models.

2606.08890 2026-06-09 math.NT math.CO 新提交

Polynomial Corners Over finite Fields

有限域上的多项式角

Laurence P. Wijaya

AI总结 研究有限域上避免多项式角结构的集合密度,通过傅里叶分析等方法得到优于整数情形的上界。

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AI中文摘要

最近,在理解避免多项式模式的$[N]^2$子集的密度方面取得了一些进展。Kravitz、Kuca和Leng证明了,如果$P\in\mathbb{Z}[z]$满足某些条件,那么任何不包含$(x,y),(x+P(z),y),(x,y+P(z))$的集合$A\subseteq[N]^2$,必须满足$|A|\ll_P\frac{N^2}{(\log\log\log N)^c}$,其中$c$是一个小常数。在本文中,我们在$(\mathbb{F}_p)^2$中展示了类似的结果,对于满足$P\in \mathbb{F}_p[z]$某些条件的多项式,我们得到了不包含$(x,y),(x+P(z),y),(x,y+P(z))$的集合$A\subseteq (\mathbb{F}_p)^2$的密度的一个更好的界。

英文摘要

Recently there has been some progress in understanding the density of a subset of $[N]^2$ that avoids polynomial patterns. Kravitz, Kuca, and Leng showed that if $P\in\mathbb{Z}[z]$ satisfies certain conditions, then any set $A\subseteq[N]^2$ does not contain $(x,y),(x+P(z),y),(x,y+P(z))$, we must have \[ |A|\ll_P\frac{N^2}{(\log\log\log N)^c} \] for some small constant $c$. In this article, we show a similar result in $(\mathbb{F}_p)^2$ where we get a better bound on the density of a set $A\subseteq (\mathbb{F}_p)^2$ not containing $(x,y),(x+P(z),y),(x,y+P(z))$ with some conditions on $P\in \mathbb{F}_p[z]$.

2606.08889 2026-06-09 hep-th gr-qc 新提交

Exact Four-Parameter Rotating NS--NS Vacuum in Double Field Theory

双场理论中精确的四参数旋转NS-NS真空

Hun Jang, Minkyoo Kim, Jeong-Hyuck Park

AI总结 通过紧致SO(2) S-对偶构造了旋转NS-NS真空解,具有四个独立参数,首次解析确定所有三个NS-NS场,静态极限下呈现轴向Zipoy-Voorhees分支并携带H通量,揭示了非黎曼几何特征。

Comments 21 pages (cover 1 + body 11 + appendix 9), 6 figures

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AI中文摘要

我们构造了一个精确的NS-NS扇区旋转真空,等价于双场理论真空。该构造将紧致$\mathbf{SO}(2)$ S-对偶应用于旋转爱因斯坦-标量种子。解具有四个独立参数$\{\mathfrak{m},j,\mathfrak{q},\zeta\}$。据我们所知,这是纯NS-NS真空方程的第一个显式旋转解,所有三个NS-NS场$\{g,B,\phi\}$均解析确定,具有独立的膨胀子和$H$-通量荷,且无麦克斯韦扇区。静态极限通过取旋转参数$j\to 0$获得。在该极限下,几何不是球对称的Burgess-Myers-Quevedo解,而是携带$H$-通量的轴向Zipoy-Voorhees分支,因此旋转关闭后仍存在扁球变形。这种几何记忆在纯广义相对论和爱因斯坦-麦克斯韦-膨胀子-轴子中不存在。然而,两个静态分支共享相同的$\ell=0$参数化后牛顿数据$\{MG,\beta_{\mathrm{PPN}},\gamma_{\mathrm{PPN}},h\}$。它们在相同单极荷下给出两个不等价的NS-NS几何,简并在$\ell=2$处解除。在克尔视界位置,外壳通常具有曲率奇异性。在阈值$|\mathfrak{q}|>\sqrt{\mathfrak{m}^{2}-j^{2}}$之上,极向测地线被向外排斥,旋转轴在外壳处曲率变得正则。在该轴上,逆度规$g^{\mu\nu}$保持有限,而下标黎曼度规分量发散,而在轴外,逆度规本身发散。这种轴局域简并可能为双场理论中的非黎曼几何提供背景,其中$g_{\mu\nu}$不是基本的,而$\mathbf{O}(D,D)$变量$\{d,\mathcal{H}_{AB}\}$保持良好定义。

英文摘要

We construct an exact rotating vacuum of the NS--NS sector, equivalently a Double Field Theory vacuum. The construction applies compact $\mathbf{SO}(2)$ S-duality to a rotating Einstein--scalar seed. The solution has four independent parameters $\{\mathfrak{m},j,\mathfrak{q},ζ\}$. To our knowledge, this is the first explicit rotating solution of the pure NS--NS vacuum equations with all three NS--NS fields $\{g,B,ϕ\}$ determined analytically, independent dilaton and $H$-flux charges, and no Maxwell sector. The static limit is obtained by taking the rotation parameter $j\to 0$. In this limit the geometry is not the spherical Burgess--Myers--Quevedo solution. Instead, it is an axial Zipoy--Voorhees branch carrying $H$-flux, so an oblate deformation remains after rotation is switched off. This geometric memory is absent in pure general relativity and in Einstein--Maxwell--dilaton--axion. The two static branches nevertheless share the same $\ell=0$ parametrized post-Newtonian data $\{MG,β_{\mathrm{PPN}},γ_{\mathrm{PPN}},h\}$. They give two inequivalent NS--NS geometries at identical monopole charges, with the degeneracy lifted at $\ell=2$. At the Kerr horizon locus the outer shell is generically singular in curvature. Above the threshold $|\mathfrak{q}|>\sqrt{\mathfrak{m}^{2}-j^{2}}$, polar geodesics are repelled outward and the rotation axis becomes regular in curvature at the shell. On that axis the inverse metric $g^{μν}$ stays finite while the lower-index Riemannian metric components diverge, whereas off the axis the inverse metric itself diverges. This axis-local degeneracy may offer a setting for non-Riemannian geometry in Double Field Theory, where $g_{μν}$ is not fundamental and the $\mathbf{O}(D,D)$ variables $\{d,\mathcal{H}_{AB}\}$ remain well defined.

2606.08887 2026-06-09 math.DG math.MG 新提交

Bounding Curvature Measure on Manifolds with Singularities

带奇点流形上的曲率测度有界性

Nan Li

AI总结 研究Alexandrov空间中去掉奇点后的光滑流形,证明其标量曲率积分由仅依赖于维数和奇点参数的常数上界控制,推广了Petrunin的有界曲率积分结果。

Comments 23 pages

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AI中文摘要

设 $X$ 是一个 $n$ 维 Alexandrov 空间,曲率 $\ge -1$,并设 $η> 0$。定义 $\mathcal{S}^{k}_η(X)$ 为 $X$ 中 $(k,η)$-奇异点的集合,这些点的切锥在等距意义下与 $\mathbb{R}^{k+1}$ 的分离程度至少为 $η$。对于点 $p \in X$,假设 $M = B_2(p) \setminus (\mathcal{S}^{n-2}_η(X) \cup \partial X)$ 是一个光滑流形,配备由 $X$ 诱导的黎曼度量。我们证明 $M$ 的标量曲率在 $B_1(p)$ 上的积分由仅依赖于 $n$ 和 $η$ 的常数上界控制。作为特例,这将在下截面曲率有界完备流形上的 Petrunin 有界曲率积分结果推广到开流形和带边光滑流形,只要这些流形是 Alexandrov 空间。

英文摘要

Let $X$ be an $n$-dimensional Alexandrov space with curvature $\ge -1$, and let $η> 0$. Define $\mathcal{S}^{k}_η(X)$ as the set of $(k,η)$-singular points in $X$ whose tangent cones are $η$-away from splitting off $\mathbb{R}^{k+1}$ isometrically. For a point $p \in X$, assume that $M = B_2(p) \setminus (\mathcal{S}^{n-2}_η(X) \cup \partial X)$ is a smooth manifold equipped with the Riemannian metric induced by $X$. We prove that the integral of the scalar curvature of $M$ over $B_1(p)$ is bounded from above by a constant depending only on $n$ and $η$. As a special case, this extends Petrunin's bounded curvature integral result for complete manifolds with lower sectional curvature bound to the setting of open manifolds and smooth manifolds with boundary, provided that these manifolds are Alexandrov spaces.

2606.08886 2026-06-09 cs.CR cs.NI 新提交

Block-A-Mole: The Sustainability Frontier of Moving-Target Censorship Resistance

Block-A-Mole: 移动目标审查抵抗的可持续性前沿

Anindya Maiti

AI总结 本文通过将审查者与防御者的交互建模为连续时间博弈,提出移动目标审查抵抗的形式化理论,发现可用性由域名燃烧率β决定,并推导出封闭形式的可用性定律,证明当β>1时仅靠地址旋转无法维持高可用性。

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AI中文摘要

互联网审查影响超过四十亿人,已部署的规避系统有一个共同弱点:它们的端点固定且可发现,因此耐心的审查者可以枚举并封锁它们。移动目标规避系统则通过比审查者反应更快的速度在商业云地址空间中轮换端点,但该领域缺乏关于轮换何时有效的理论,使得轮换间隔和池大小依赖于直觉。我们首次给出了移动目标审查抵抗的形式化描述,将审查者-防御者交互建模为在组合地址域空间上的连续时间定时博弈,将FlipIt推广到具有附带限制的对手。我们证明了一个可持续性前沿,将审查者能够击败的配置与不能击败的配置分开,并表明在2024年防火长城转向按域名封锁QUIC和TLS的情况下,原始轮换速度不是约束条件。相反,可用性由域名燃烧率$β=λ_{\mathrm{disc}}/λ_{\mathrm{intro}}$决定,即审查者封锁防御者域名的速度与防御者引入新域名的速度之比。我们推导出封闭形式的可用性定律,证明当$β>1$时,无论端点轮换速度如何,仅靠地址旋转无法维持高可用性,并刻画了前沿$β^\star$。我们通过一个开放的、模型级别的审查者-防御者模拟器验证了分析,该模拟器无需特权访问或云部署。模拟器在代表GFW、俄罗斯TSPU和伊朗的对手配置下重现了$β^\star$处的预测相变,并显示出对状态依赖发现和突发性、提供商相关燃烧的鲁棒性。结果将“更快轮换”的启发式替换为精确的操作条件:保持域名经济领先于审查者。

英文摘要

Internet censorship affects over four billion people, and deployed circumvention systems share a common weakness: their endpoints are fixed and discoverable, so a patient censor can enumerate and block them. Moving-target circumvention systems instead rotate endpoints across commercial cloud address space faster than censors can react, but the field lacks a theory of when rotation works, leaving rotation intervals and pool sizes to intuition. We give the first formal account of moving-target censorship resistance by modeling the censor-defender interaction as a continuous-time timing game over a combinatorial address-domain space, generalizing FlipIt to a collateral-bounded adversary. We prove a sustainability frontier separating configurations a censor can defeat from those it cannot, and show that under the Great Firewall's 2024 shift to blocking QUIC and TLS by domain, raw rotation speed is not the binding constraint. Instead, availability is governed by the domain burn rate, $β=λ_{\mathrm{disc}}/λ_{\mathrm{intro}}$, the ratio between how quickly the censor blocks defender domains and how quickly the defender introduces fresh ones. We derive a closed-form availability law, prove that address rotation alone cannot sustain high availability when $β>1$ regardless of endpoint rotation speed, and characterize the frontier $β^\star$. We validate the analysis with an open, model-level censor-defender simulator requiring no privileged access or cloud deployment. The simulator reproduces the predicted phase transition at $β^\star$ under adversary profiles representative of the GFW, Russia's TSPU, and Iran, and shows robustness to state-dependent discovery and bursty, provider-correlated burns. The result replaces the heuristic of ``rotate faster'' with a precise operating condition: keeping the domain economy ahead of the censor.

2606.08885 2026-06-09 cs.ET physics.optics 新提交

Silicon Photonics Testing: Design for Testability, Fault Detection, and Manufacturing Variation Analysis in Photonic Integrated Circuits

硅光子学测试:光子集成电路的可测试性设计、故障检测与制造变异分析

Pratishtha Agnihotri, Priyank Kalla, Steve Blair

AI总结 提出一种硅光子集成电路的可测试性设计(DFT)方法与架构,通过仿真验证测试通路和故障检测电路,并在光神经网络和光逻辑电路中展示其应用。

Comments A short version of this paper is presented at a conference. P. Agnihotri, P. Kalla and S. Blair, "Design-for-Test for Silicon Photonic Circuits," 2024 IEEE International Test Conference (ITC), San Diego, CA, USA, 2024, pp. 86-90, doi: 10.1109/ITC51657.2024.00025

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AI中文摘要

本文提出了一种用于硅光子集成电路测试与验证的可测试性设计(DFT)方法和架构。我们描述了构成所提议DFT架构的硅光子电路和组件的设计。这些设计被广泛仿真并验证为测试通路和故障检测电路。我们展示了如何将DFT方法部署在光子集成电路上,以及如何测试它们在信号功率和相位方面的正确操作。该应用在两种不同类型的设计上进行了演示——一种是由前馈拓扑中的光学器件组成的光学神经网络,另一种是具有反馈回路的光学逻辑电路。

英文摘要

This paper proposes a design-for-test (DFT) methodology and architecture for testing and validation of silicon photonic integrated circuits. We describe the design of silicon photonic circuits and components that comprise the proposed DFT architecture. The designs are extensively simulated and validated as test-access and fault-detection circuitry. We demonstrate how the DFT approach can be deployed on photonic integrated circuits and how they can be tested for correct operation, in terms of signal power and phase. The application is demonstrated on two distinct types of designs -- an optical neural network comprising optical devices in a feed-forward topology, and on an optical logic circuit with feedback loops.

2606.08884 2026-06-09 math.PR 新提交

A Poincaré Inequality and Exponential Decay for the Elephant Random Walk

大象随机游走的庞加莱不等式与指数衰减

Cristian Favio Coletti, Rafael de Mattos Grisi, Ioannis Papageorgiou

AI总结 研究带吸收边界的一维连续时间大象随机游走的长时间行为,通过分析演化方程建立谱间隙为N^{-2}阶的庞加莱不等式,得到生存概率以e^{-ct/N^2}速率指数衰减。

Comments 15 pages

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AI中文摘要

我们研究带吸收边界的连续时间一维大象随机游走的长时间行为。通过分析相关的演化方程,我们识别出一个合适的极限算子,并建立了一个谱间隙为$N^{-2}$阶的庞加莱不等式。作为结果,我们得到了生存概率的匹配指数上界和下界,表明它以$e^{-ct/N^2}$的速率衰减。证明依赖于将生成元分解为极限算子和时间依赖的扰动,以及谱估计。

英文摘要

We study the long-time behaviour of a coninuous time one-dimensional elephant random walk with an absorbing boundary. By analyzing the associated evolution equation, we identify a proper limiting operator and establish a Poincaré inequality with spectral gap of order $N^{-2}$. As a consequence, we obtain matching exponential upper and lower bounds for the survival probability, showing that it decays at rate $e^{-ct/N^2}$. The proof relies on a decomposition of the generator into a limiting operator and a time-dependent perturbation, together with spectral estimates.

2606.08883 2026-06-09 math.NA cs.NA 新提交

Accelerating GMRES with Matrix-Free Multiscale Robin Preconditioners

使用无矩阵多尺度Robin预条件子加速GMRES

Dilong Zhou, Rafael T. Guiraldello, Felipe Pereira, Fabrício S. Sousa

AI总结 提出一种基于过采样多尺度Robin耦合方法的无矩阵右预条件策略,用于GMRES求解地下流椭圆问题,显著减少迭代次数,常在一两次迭代内收敛。

Comments 36 pages, 8 figures, 7 tables

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AI中文摘要

我们提出了一种基于过采样多尺度Robin耦合方法(MRCM-OS)的无矩阵右预条件策略,用于广义最小残差(GMRES)方法求解地下流中的椭圆问题。所得到的预条件子通过局部子域求解(带过采样和平滑)构造,无需显式组装全局算子即可应用。在详细阐述新流程后,我们将其用于大量数值实验。结果表明,所提出的方法在一系列具有挑战性的高对比度地下流问题中显著减少了迭代次数。在许多情况下,当采用过采样和平滑时,只需一两次GMRES迭代即可收敛。结果表明,将GMRES与多尺度Robin算子相结合是构建快速收敛预条件策略的一个有前景的方向。

英文摘要

We propose a matrix-free right-preconditioning strategy for the Generalized Minimal Residual (GMRES) method based on the Multiscale Robin Coupled Method with oversampling (MRCM-OS) for the numerical solution of elliptic problems arising in subsurface flow. The resulting preconditioner is constructed through local subdomain solves with oversampling and smoothing, and can be applied without explicit assembly of the global operator. After a careful presentation of the new procedure, it is used in extensive numerical experiments. Our results demonstrate that the proposed approach substantially reduces iteration counts across a range of challenging, high-contrast subsurface flow problems. In many cases, convergence is obtained in one or two GMRES iterations when oversampling and smoothing are employed. The results indicate that combining GMRES with multiscale Robin-based operators is a promising direction for the construction of rapidly convergent preconditioning strategies.

2606.08882 2026-06-09 math.AG math.CA math.NT 新提交

Algebraic Hodge generic points are dense

代数Hodge一般点是稠密的

Gregorio Baldi, Gal Binyamini, David Urbanik

AI总结 本文证明在拟射影族中,Hodge一般点在代数点上解析稠密,并在大单值假设下证明周期无额外关系的点的稠密性,同时建立Mumford-Tate猜想的新实例。

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AI中文摘要

设 $f: X \to S$ 是定义在 $\overline{\mathbb{Q}} \subset \mathbb{C}$ 上的拟射影簇族。我们证明,对于与 $f$ 关联的Hodge结构的变化,$S(\overline{\mathbb{Q}})$ 中Hodge一般的点在 $S(\mathbb{C})$ 中是解析稠密的。事实上,遵循Grothendieck周期猜想的精神并在大单值假设下,我们证明了 $S(\overline{\mathbb{Q}})$ 中纤维的周期在“$\delta$ 次”内不满足额外关系的点的稠密性。作为副产品,我们还在阿贝尔动机领域之外建立了Mumford-Tate猜想的新实例。当基 $S$ 是曲线时,我们为满足这些性质的点提供了定量估计。主要技术贡献是关于 $G$-算子解所满足关系的一个新结果,该结果依赖于Bombieri和André的高度估计。

英文摘要

Let $f: X \to S$ be a quasi-projective family of varieties defined over $\overline{\mathbb{Q}} \subset \mathbb{C}$. We show that the points of $S(\overline{\mathbb{Q}})$ that are Hodge generic for the variation of Hodge structures associated to $f$ are analytically dense in $S(\mathbb{C})$. In fact, in the spirit of the Grothendieck period conjecture and under a large monodromy assumption, we prove the density of the points of $S(\overline{\mathbb{Q}})$ where the periods of the fibre do not satisfy extra relations 'up to degree $δ$'. As a by-product, we also establish new instances of the Mumford-Tate conjecture, beyond the realm of abelian motives. When the base $S$ is a curve, we provide quantitative estimates for points satisfying these properties. The main technical contribution is a new result on relations satisfied by solutions of $G$-operators, which relies on height estimates due to Bombieri and André.

2606.08880 2026-06-09 eess.SY cs.SY 新提交

Direct Data-driven Predictive Control: A Computationally Efficient Alternative to DeePC for Eco-driving in Mixed Traffic Flows

直接数据驱动预测控制:混合交通流中生态驾驶的 DeePC 计算高效替代方案

Dongjun Li, Haoxuan Dong, Liangcai Xu, Ziyou Song

AI总结 提出直接数据驱动预测控制(D3PC)框架,通过重构数据驱动预测机制降低计算复杂度,实现混合交通中网联自动驾驶汽车的实时生态驾驶,能耗比 DeePC 降低 3.80%。

Comments 6 pages

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AI中文摘要

提高交通领域的能源效率对于实现可持续出行至关重要,生态驾驶已成为一项关键策略。然而,由于人类驾驶车辆(HDV)的异质性和不确定性行为,在混合交通中为网联自动驾驶汽车(CAV)实施有效的生态驾驶带来了显著的控制挑战。数据驱动预测控制(DeePC)提供了一种有前景的无模型方法,但通常受到高计算负担的限制,阻碍了其实时可行性。本文引入了一种新颖的直接数据驱动预测控制(D3PC)框架来解决这一限制。通过重构数据驱动预测机制,D3PC 显著降低了计算复杂度,使其计算时间几乎不随历史数据规模变化。这种计算效率直接支持构建复杂的生态驾驶控制器,使其能够在多样化和随机混合交通环境中实时求解复杂的能量优化问题。综合仿真表明,D3PC 比现有基于 DeePC 的方法快数个数量级,同时实现了更优的能源效率。具体而言,与基于规则的巡航控制基线相比,它使车队总能耗降低高达 10.71%,与原始 DeePC 相比降低 3.80%,证实了其在实时、节能控制中的有效性。

英文摘要

Improving energy efficiency in the transportation sector is critical for achieving sustainable mobility, with eco-driving emerging as a key strategy. However, implementing effective eco-driving for connected and automated vehicles (CAVs) in mixed traffic presents a significant control challenge due to the heterogeneous, uncertain behavior of human-driven vehicles (HDVs). Data-enabled Predictive Control (DeePC) offers a promising model-free approach but is often hindered by a high computational burden, limiting its real-time feasibility. This paper introduces a novel Direct Data-driven Predictive Control (D3PC) framework to address this limitation. By reformulating the data-driven prediction mechanism, the D3PC significantly reduces computational complexity, making its computation time nearly invariant to historical data size. This computational efficiency directly enables the formulation of a sophisticated eco-driving controller that can solve the complex energy optimization problem in real time, even within diverse and stochastic mixed-traffic environments. Comprehensive simulations demonstrate that the D3PC is orders of magnitude faster than existing DeePC-based methods while achieving superior energy efficiency. Specifically, it reduces total platoon energy consumption by up to 10.71% compared to rule-based cruise control baselines and 3.80% compared to the original DeePC, confirming its effectiveness for real-time, energy-efficient control.

2606.08879 2026-06-09 hep-ph hep-th 新提交

Detector Resolution and Observable Infrared Memory in QED

QED中的探测器分辨率与可观测红外记忆

Takeshi Fukuyama

AI总结 本文强调探测器分辨率尺度ω_max作为硬子空间粗粒化尺度的自然解释,并指出可观测红外记忆不仅由渐近软光子决定,还受观测与未观测红外自由度之间的分辨率尺度影响。

Comments 3 pages, no figure

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AI中文摘要

QED中的红外发散通过Bloch-Nordsieck和KLN机制在包含性可观测量中抵消。然而,这种抵消仅移除了非物理的红外调节器。探测器分辨率尺度ω_max(指定未分辨软光子的最大能量)仍保留在可观测截面中。我们强调,这个存留的尺度在硬子空间的约化密度矩阵中具有自然的粗粒化尺度解释。低于ω_max的软光子未被观测,并有效被求迹。因此,相应的软子空间重叠变得依赖于分辨率,即D_{ij}=D_{ij}(ω_max)。因此,可观测红外记忆不仅由渐近软子空间本身定义,还由分隔观测与未观测红外自由度的分辨率尺度定义。这为传统的红外安全截面表述与软光子作为红外记忆和量子信息载体的现代解释之间提供了桥梁。

英文摘要

Infrared divergences in QED cancel in inclusive observables through the Bloch--Nordsieck and KLN mechanisms. However, this cancellation removes only the unphysical infrared regulator. The detector resolution scale $ω_{\max}$, which specifies the maximum energy of unresolved soft photons, remains in the observable cross section. We emphasize that this surviving scale has a natural interpretation as a coarse-graining scale in the reduced density matrix of the hard sector. Soft photons below $ω_{\max}$ are not observed and are effectively traced over. The corresponding soft-sector overlap therefore becomes resolution dependent, $D_{ij}=D_{ij}(ω_{\max})$. Observable infrared memory is consequently defined not only by the asymptotic soft sector itself, but also by the resolution scale separating observed and unobserved infrared degrees of freedom. This provides a bridge between the traditional infrared-safe cross-section formulation and the modern interpretation of soft photons as carriers of infrared memory and quantum information.

2606.08877 2026-06-09 math.AP 新提交

On product estimates in Besov-Morrey spaces and stationary solutions for the Hall-MHD and Navier-Stokes systems

关于Besov-Morrey空间中的乘积估计以及Hall-MHD和Navier-Stokes系统的平稳解

Lucas C. F. Ferreira, Rafael P. da Silva

AI总结 本文在尺度不变的Besov-Morrey空间中研究三维稳态不可压缩电阻粘性Hall-MHD系统的适定性,通过推导乘积估计处理非线性项,并推广到Navier-Stokes方程。

Comments 26 pages

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AI中文摘要

本文在尺度不变的Besov-Morrey空间框架下,研究了三维稳态不可压缩电阻粘性Hall磁流体动力学(Hall-MHD)系统的适定性。我们分析的关键组成部分是在这些空间中推导乘积估计,这对于处理系统的非线性项至关重要。作为应用,我们还在该设定下建立了稳态Navier-Stokes方程的适定性结果,从而拓宽了外力与解的可容许类。

英文摘要

In this paper, we investigate the well-posedness of the three-dimensional stationary incompressible resistive-viscous Hall magnetohydrodynamic (Hall-MHD) system within the framework of scale-invariant Besov-Morrey spaces. A key component of our analysis is the derivation of product estimates in these spaces, which are instrumental in handling the system's nonlinear terms. As an application, we also establish a well-posedness result for the stationary Navier-Stokes equations in this setting, thereby broadening the admissible classes of external forces and solutions.

2606.08876 2026-06-09 physics.geo-ph 新提交

RO-LiDAR GeoQuickView: A Web Platform for Exploring Public LiDAR-Derived Elevation Data in Romania

RO-LiDAR GeoQuickView:探索罗马尼亚公共LiDAR衍生高程数据的Web平台

Alexandru Hegyi

AI总结 提出一个非商业Web-GIS平台RO-LiDAR GeoQuickView,整合公共LiDAR衍生数字地形模型等高程数据,提供标准化山体阴影可视化、参与式景观记录和空间索引,以解决数据碎片化和专业处理限制问题。

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AI中文摘要

公共高程数据可以支持景观研究、环境解释、规划、教育和公众参与,但其实际重用常常受到碎片化交付和专业处理要求的限制。本文介绍了RO-LiDAR GeoQuickView,一个独立的、自愿的、非商业的Web-GIS倡议,用于探索和重用罗马尼亚的公共可访问高程数据。该平台整合了LiDAR衍生的数字地形模型(DTM)和不同分辨率的补充高程模型,发布标准化的山体阴影可视化以便立即在浏览器中访问,支持参与式景观记录,并提供用于直接栅格检索的空间索引。其目前最详细的集成组件是覆盖卡拉什-塞维林、戈尔日、梅赫丁茨和多尔日县的0.5米LAKI III A区DTM。下一个计划的高分辨率扩展是LAKI III B区,包括苏恰瓦、尼亚姆茨、巴克乌和弗朗恰县。它将在公共产品可用并通过相同的协调和质量控制工作流程后集成。该平台还通过一个源感知处理工作流程整合了LAKI II和其他公共测高源,该工作流程适应不同的采集单元,包括一公里单元和更大的栅格块。本文记录了数据架构、协调步骤、质量控制程序、访问模式、应用范围和局限性。该平台被设想为公共数据基础设施上的可访问性层:它支持快速发现和初步解释,但不替代官方产品、专业建模、专家审查或现场验证。

英文摘要

Public elevation data can support landscape research, environmental interpretation, planning, education, and public engagement, but their practical reuse is often limited by fragmented delivery and specialist processing requirements. This paper presents RO-LiDAR GeoQuickView, an independent, voluntary, and non-commercial Web-GIS initiative for exploring and reusing publicly accessible elevation data in Romania. The platform integrates LiDAR-derived digital terrain models (DTMs) and complementary elevation models of different resolutions, publishes standardized hillshade visualizations for immediate browser access, supports participatory landscape documentation, and provides a spatial index for direct raster retrieval. Its most detailed currently integrated component is the 0.5 m LAKI III Zone A DTM coverage for Caras-Severin, Gorj, Mehedinti, and Dolj counties. LAKI III Zone B, comprising Suceava, Neamt, Bacau, and Vrancea counties, is the next scheduled high-resolution extension. It will be integrated after the public products become available and pass through the same harmonization and quality-control workflow. The platform also incorporates LAKI II and additional public altimetric sources through a source-aware processing workflow that accommodates different acquisition units, including one-kilometre cells and larger raster blocks. The paper documents the data architecture, harmonization steps, quality-control procedures, access modes, application range, and limitations. The platform is conceived as an accessibility layer over public data infrastructures: it supports rapid discovery and preliminary interpretation, but it does not replace official products, specialist modelling, expert review, or field verification.

2606.08874 2026-06-09 quant-ph cond-mat.mes-hall 新提交

Impact of gate-voltage noise on silicon spin-qubit variational quantum eigensolvers

栅极电压噪声对硅自旋量子比特变分量子本征求解器的影响

Xinning Wang, Bohdan Khromets, Zachery Merino, Jonathan Baugh

AI总结 针对硅自旋量子比特,开发硬件-算法协同仿真框架,研究栅极电压噪声(静态失谐和随机电报噪声)对VQE算法计算H₂基态能量的影响,发现交换双量子比特门灵敏度比单量子比特旋转高一个数量级,并确定实现化学精度的噪声容忍范围。

Comments 27 pages, 17 figures

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AI中文摘要

量子计算机在分子模拟等任务中提供了超越经典方法的途径,推动了用于近期设备的变分量子本征求解器(VQE)等混合算法的发展。硅自旋量子比特是可扩展量子计算的一个有前景的平台,但其性能受到硬件缺陷的限制——最显著的是电荷噪声引起的电势波动和栅电极电压的静态失谐——这些缺陷降低了量子门保真度,并最终影响算法精度。本文针对硅量子点处理器开发了一种硬件-算法协同仿真框架,该框架将3D静电学与有效$g$因子和交换耦合联系起来,并通过实际控制脉冲传播电压级噪声。以$\mathrm{H}_2$基态能量估计的VQE作为电路级测试平台,我们研究了栅电极电压上的静态缩放/偏移误差以及建模为随机电报噪声(具有可调幅度和切换时间)的随机波动。在门级,我们表明基于交换的双量子比特门对这些类型噪声的敏感度大约比ESR驱动的单量子比特旋转高一个数量级。量子过程层析成像和Kraus算子分析进一步区分了相干和非相干贡献,并量化了原则上可通过补偿酉变换纠正的误差比例。将这些噪声模型嵌入VQE电路后,我们确定了与化学精度能量估计兼容的失谐强度和噪声切换时间范围,并讨论了基于噪声能量估计完整分布的统计后处理如何进一步提高精度。

英文摘要

Quantum computers offer a route to outperform classical methods in tasks such as molecular simulation, motivating hybrid algorithms like the Variational Quantum Eigensolver (VQE) for near-term devices. Silicon spin qubits are a promising platform for scalable quantum computation, but their performance is limited by hardware imperfections -- most notably charge-noise-induced potential fluctuations and static miscalibration of gate-electrode voltages -- which degrade quantum gate fidelities and, ultimately, algorithmic accuracy. Here we develop a hardware-algorithm co-simulation framework for silicon quantum-dot processors that links 3D electrostatics to effective $g$-factors and exchange couplings, and propagates voltage-level noise through realistic control pulses. Using VQE for $\mathrm{H}_2$ ground-state energy estimation as a circuit-level testbed, we study both static scaling/offset errors on the gate-electrode voltages and stochastic fluctuations modeled as random-telegraph noise with tunable amplitudes and switching times. At the gate level, we show that exchange-based two-qubit gates are roughly an order of magnitude more sensitive to these types of noise than ESR-driven single-qubit rotations. Quantum process tomography and Kraus-operator analysis further distinguish coherent and incoherent contributions and quantify the fraction of error that is, in principle, correctable by a compensating unitary. Embedding these noise models into the VQE circuit, we identify regimes of miscalibration strength and noise switching time compatible with chemically accurate energy estimates, and discuss how statistical post-processing based on the full distribution of noisy energy estimates could further improve accuracy.

2606.08873 2026-06-09 quant-ph cs.NI 新提交

SCOPE: A Syndrome-Driven Control Plane for QEC-Enabled Quantum Networks

SCOPE:一种面向QEC使能量子网络的综合征驱动控制平面

Xiaojie Fan, Zian Wang, Ashutosh Tiwari, Himanshu Gupta

AI总结 提出SCOPE架构,通过被动收集QEC解码器产生的错误综合征,实现路由与编码的联合优化,相比传统方法降低逻辑错误率30-35%。

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AI中文摘要

随着量子网络从实验测试平台演变为容错系统,主要性能指标从物理链路保真度转变为端到端逻辑错误率。然而,当前控制平面对此转变准备不足:路由决策通常与量子纠错(QEC)策略解耦,依赖于拓扑或标量保真度指标,无法预测特定物理噪声结构与逻辑码的相互作用。优化这种耦合的路由-编码性能需要精确、实时的网络错误偏差可见性,但传统的主动层析成像由于吞吐量下降和服务中断而在操作上不可行。我们提出SCOPE(基于综合征的控制平面),一种网络层架构,通过纯被动遥测实现路由和编码的联合优化。SCOPE不注入探测包,而是收集错误综合征——用户服务期间QEC解码器自然产生的奇偶校验结果。通过聚合这些信号,SCOPE的推理引擎重建网络的时变错误图,捕捉复杂、上下文相关的噪声相关性。这种可见性驱动决策引擎,主动向源节点推送最优的路由-编码配置。NetSquid和IBM校准的仿真表明,相对于标准EM基线,SCOPE将估计误差降低超过60%。在大规模网络中,这种精度使逻辑错误率相对于拓扑感知基线降低30-35%(高达65%)。

英文摘要

As quantum networks evolve from experimental testbeds to fault-tolerant systems, the primary performance metric shifts from physical link fidelity to end-to-end logical error rate. However, current control planes remain ill-equipped for this transition: routing decisions are typically decoupled from Quantum Error Correction (QEC) strategies, relying on topology or scalar fidelity metrics that fail to predict how specific physical noise structures interact with logical codes. Optimizing this coupled route-and-code performance requires precise, real-time visibility into network error biases, yet traditional active tomography is operationally prohibitive due to throughput collapse and service interruption. We present SCOPE (Syndrome-based COntrol PlanE), a network-layer architecture that enables joint routing and coding optimization using purely passive telemetry. Instead of injecting probes, SCOPE harvests error syndromes -- the parity-check outcomes naturally generated by QEC decoders during user service. By aggregating these signals, SCOPE's inference engine reconstructs the network's time-varying error map, capturing complex, context-dependent noise correlations. This visibility drives a decision engine that proactively pushes optimal route-and-code configurations to source nodes. NetSquid and IBM-calibrated simulations show that SCOPE reduces estimation error by more than 60% relative to a standard EM baseline. In large-scale networks, this precision reduces logical error rates by 30-35% (up to 65%) against topology-aware baselines.

2606.08872 2026-06-09 cs.GT econ.TH 新提交

EFX for Additive Chores: Nonexistence, Pareto Incompatibility, and Bi-Valued Existence

可加性杂务的EFX:不存在性、帕累托不相容性与双值存在性

Wentao He, Biaoshuai Tao

AI总结 本文证明了对于可加性成本函数,当代理数n≥4且成本类型至少3种时,EFX分配可能不存在;并首次展示双值实例中EFX与帕累托最优不相容。

Comments 31 pages

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AI中文摘要

我们考虑不可分割杂务的公平分配问题,并解决了关于可加性成本函数下EFX分配存在性的长期未决问题。我们证明,即使对于三值可加性成本函数,对于每个$n\geq 4$,都存在一个包含$n$个代理的实例,其中不存在EFX分配。我们的反例仅使用三种类型的杂务,这在类型数量上也是紧的,因为已知对于两种类型的杂务存在EFX分配。\n然后我们考虑双值实例。我们证明,对于每个$n\geq 4$,都存在一个包含$n$个代理的实例,其中每个EFX分配都不是帕累托最优的。这也是第一个展示当物品成本为正时EFX与帕累托最优不相容的例子:现有展示EFX与帕累托最优不相容的例子利用了成本为0的物品。我们的结果表明即使对于双值实例也存在这样的例子。代理数量$n$也是紧的:对于$n\leq 3$,已知EFX与帕累托最优相容。最后,我们还证明对于$n=4$,EFX分配保证存在。

英文摘要

We consider the fair division problem of indivisible chores and resolve the long-standing open problem for the existence of EFX allocations with additive cost functions. We show that, even for tri-valued additive cost functions, for every $n\geq 4$, there exists an instance with $n$ agents where no EFX allocation exists. Our counterexample only uses three types of chores, which is also tight on the number of types, as an EFX allocation is known to exist for two types of chores. We then consider bi-valued instances. We show that, for every $n\geq 4$, there exists an instance with $n$ agents where every EFX allocation is not Pareto-optimal. This is also the first example showing the incompatibility of EFX and Pareto-optimality when the costs of items are positive: existing examples showing the incompatibility of EFX and Pareto-optimal exploit items with $0$ costs. Our result shows such an example exists even for bi-valued instances. The number of agents $n$ is also tight: for $n\leq 3$, it is known that EFX is compatible with Pareto-optimality. Finally, we also show that an EFX allocation is guaranteed to exist for $n=4$.

2606.08870 2026-06-09 physics.atom-ph quant-ph 新提交

A nuclear clock based on $^{229}$Th

基于$^{229}$Th的核时钟

Beichen Huang, Gaowei Yan, Qi Xiao, Wenhao Bu, Zhen Zhang, Chengchun Zhao, Chao Yan, Zhi-Ang Chen, Peixiong Zhang, Gleb Penyazkov, Zhenhai Zhan, Lingfeng Yan, Yuefei Wang, Lin Li, Shanming Li, Xiaobo Qian, Xuegang Liu, Qiange He, Taoxiang Sun, Haochen Tian, Binkun Lu, Ningyuan Ma, Juxian Li, Yanzhang Wu, Qiaorui Gong, Yuxiang Li, Haoyu Shi, Xiangliang Li, Longsheng Ma, Shining Zhu, Yuxiang Mo, Jun Lin, Li You, Yige Lin, Xibo Zhang, Yin Hang, Liangbi Su, Shiqian Ding

AI总结 本文通过将窄线宽148.4 nm VUV激光锁定到固态$^{229}$Th:CaF$_2$晶体中的核跃迁,演示了$^{229}$Th核时钟的运行,实现了$2\times10^{-12}/\sqrt{\tau/s}$的分数频率不稳定性,并验证了固态核频率参考的可重复性。

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AI中文摘要

原子钟使时间和频率成为物理学中测量最精确的量,从实现SI秒的微波标准发展到现在达到前所未有的精度水平的光学钟。核时钟将频率参考从电子跃迁转移到$^{229}$Th原子核中独特的低能、激光可访问的同核异能跃迁,为紧凑、稳健的计时和基础物理的灵敏测试提供了途径。然而,将$^{229}$Th核共振光谱学的最新进展转化为时钟运行,需要核跃迁作为稳定的鉴频器来引导可溯源的振荡器。在这里,我们通过将连续波窄线宽148.4 nm真空紫外(VUV)激光锁定到固态宿主中已分辨的核跃迁,演示了$^{229}$Th核时钟的运行。这种时钟运行得益于基于光电管光电流读出透射VUV功率的快速频率鉴频。由镉蒸气中四波混频产生的10 $\mu$W VUV激光,从自生长的$^{229}$Th:CaF$_2$晶体中提供高信噪比的吸收信号,使激光能够锁定到弱温度敏感的核跃迁。该时钟达到$2\times10^{-12}/\sqrt{\tau/s}$的分数频率不稳定性,其中$\tau$是平均时间。值得注意的是,用两个不同晶体测量的核时钟频率在$10^{-13}$水平上一致,证明了固态核频率参考的可重复性。通过使激光寻址的原子核成为可运行的时钟参考,这项工作将量子计量学从电子跃迁扩展到核跃迁,并为紧凑型时钟、固态核量子传感器和基础物理的精密测试开辟了新平台。

英文摘要

Atomic clocks have made time and frequency the most precisely measured quantities in physics, progressing from microwave standards that realize the SI second to optical clocks that now reach unprecedented levels of precision. A nuclear clock would shift the frequency reference from an electronic transition to the uniquely low-lying, laser-accessible isomeric transition in the $^{229}$Th nucleus, offering a route to compact, robust timekeeping and sensitive tests of fundamental physics. However, turning recent advances in spectroscopy of the $^{229}$Th nuclear resonance into clock operation requires the nuclear transition to serve as a stable discriminator for steering a traceable oscillator. Here we demonstrate the operation of a $^{229}$Th nuclear clock by stabilizing a continuous-wave narrow-linewidth 148.4 nm vacuum-ultraviolet (VUV) laser to a resolved nuclear transition in a solid-state host. This clock operation is enabled by fast frequency discrimination based on phototube photocurrent readout of the transmitted VUV power. The 10 $μ$W VUV laser, generated by four-wave mixing in cadmium vapour, provides a high-signal-to-noise absorption signal from a home-grown $^{229}$Th:CaF$_2$ crystal, allowing the laser to be locked to a weakly temperature-sensitive nuclear transition. The clock reaches a fractional frequency instability of $2\times10^{-12}/\sqrt{τ/s} $, where $τ$ is the averaging time. Remarkably, nuclear-clock frequencies measured with two distinct crystals agree at the $10^{-13}$ level, demonstrating the reproducibility of solid-state nuclear frequency references. By making a laser-addressed atomic nucleus an operational clock reference, this work extends quantum metrology from electronic to nuclear transitions, and opens a new platform for compact clocks, solid-state nuclear quantum sensors and precision tests of fundamental physics.

2606.08869 2026-06-09 cs.DC 新提交

A Low-Latency Semantic State Estimator using Latent Predictive Learning for Dynamic Network Monitoring and Orchestration

一种用于动态网络监控与编排的低延迟语义状态估计器,基于潜在预测学习

Hari Madhukumar, Haiyuan Li, Xiaolan Liu, Andy Corston-Petrie, Dimitra Simeonidou

AI总结 提出潜在预测状态估计器(LPSE),通过将变基数节点遥测转换为拓扑自适应表示并与监控问题融合,实现固定成本单次推理,在Kubernetes集群上达到82.42%语义预测准确率,推理延迟降低约41倍,内存占用减少15倍。

Comments 6 pages, 2 figures, 2 tables. Submitted to IEEE GLOBECOM 2026

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AI中文摘要

闭环网络监控与编排越来越需要超越原始计数器收集的实时遥测语义解释。然而,动态云边环境在运行时同时改变活动节点集和监控查询,而控制回路要求有界的毫秒级响应。我们提出了一种用于动态网络监控与编排的潜在预测状态估计器(LPSE),它基于对流式遥测的潜在预测学习。该框架将变基数节点遥测转换为拓扑自适应时间表示,将其与监控问题融合,并从语义码本中返回有界答案,而不是自回归文本生成。这种设计实现了固定成本、单次推理,同时保持了语义可解释性。通过操作基于稳定身份键的排列不变、槽路由节点表示,模型保持固定的输入空间,并泛化到节点添加、移除和重新排序而无需重新训练。在多节点Kubernetes集群上的实验结果表明,与可部署的4B LLM端点相比,语义预测准确率达到82.42%,平均推理延迟降低约41倍,内存占用减少15倍。

英文摘要

Closed-loop network monitoring and orchestration increasingly require semantic interpretations of live telemetry beyond raw counter collection. However, dynamic cloud-edge environments change both the active node set and the monitoring query at runtime, while control loops demand bounded millisecond-scale responses. We introduce a latent predictive state estimator (LPSE) for dynamic network monitoring and orchestration, built on latent predictive learning over streaming telemetry. The framework converts variable-cardinality node telemetry into topology-adaptive temporal representations, fuses them with monitoring questions, and returns bounded answers from a semantic codebook instead of autoregressive text generation. This design enables fixed-cost, single-pass inference while preserving semantic interpretability. By operating on permutation-invariant, slot-routed node representations keyed by stable identity, the model maintains a fixed input space and generalizes to node addition, removal, and reordering without retraining. Experimental results on a multi-node Kubernetes cluster show semantic prediction accuracy of 82.42% at approximately 41$\times$ lower mean inference latency and 15$\times$ smaller memory footprint compared with a deployable 4B LLM endpoint.

2606.08865 2026-06-09 math.NT 新提交

The Dirichlet spectrum with respect to $L_1$ norm is $\left[\frac12,1\right]$

关于 $L_1$ 范数的 Dirichlet 谱是 $\left[\frac12,1\right]$

Nikita Shulga

AI总结 证明一维 Dirichlet 谱在 $L_1$ 范数下为 $[1/2,1]$,等价于 Minkowski 谱为 $[1/4,1/2]$,并研究 Minkowski 常数水平集的 Hausdorff 维数。

Comments 29 pages including one Appendix. Comments are welcome

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AI中文摘要

我们证明关于 $L_1$ 范数逼近的一维 Dirichlet 谱 $\mathbb{D}^{[1]}$ 满足 $$ \mathbb{D}^{[1]}=\left[\frac12,1\right]. $$ 这等价于与 Minkowski 对角连分数相关的 Minkowski 谱 $\mathbb M$ 满足 $$ \mathbb M=\left[\frac14,\frac12\right]. $$ 进一步,我们证明水平集 $$ \Theta_m=\{\alpha\in(0,1)\setminus\mathbb Q:\mathfrak m(\alpha)=m\}, $$ 其中 $\mathfrak{m}(\alpha)$ 是 $\alpha$ 的 Minkowski 常数,对于任意 $m\in(1/4,1/2]$ 具有严格大于 $1/2$ 的 Hausdorff 维数,而 $\dim_H \Theta_{1/4}=\frac{1}{2}$。

英文摘要

We prove that the one-dimensional Dirichlet spectrum with respect to approximation in $L_1$ norm $\mathbb{D}^{[1]}$ satisfies $$ \mathbb{D}^{[1]}=\left[\frac12,1\right]. $$ This is equivalent to the fact that the Minkowski spectrum $\mathbb M$, associated with the Minkowski diagonal continued fraction, satisfies $$ \mathbb M=\left[\frac14,\frac12\right]. $$ Further, we show that level sets $$ Θ_m=\{α\in(0,1)\setminus\mathbb Q:\mathfrak m(α)=m\}, $$ where $\mathfrak{m}(α)$ is the Minkowski constant of $α$, have Hausdorff dimension strictly greater than $1/2$ for any $m\in(1/4,1/2]$, while $\dim_H Θ_{1/4}=\frac{1}{2}$.

2606.08863 2026-06-09 math.LO 新提交

Monotone convergence theorems equivalent to Markov's principle

单调收敛定理等价于马尔可夫原理

Douglas S. Bridges

AI总结 引入临时收敛、负收敛和表观收敛概念,证明在Bishop构造性数学中,马尔可夫原理等价于“每个临时收敛到0的递减实数列实际收敛到0”,且将“临时”替换为“负”时等价性仍成立;最后通过反Specker原理关联表观收敛与收敛。

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AI中文摘要

引入了临时收敛、负收敛和表观收敛到0的概念。然后证明,在Bishop风格的构造性数学中,马尔可夫原理等价于命题“每个临时收敛到0的递减实数列实际收敛到0”,并且当将“临时”替换为“负”时,该等价性仍然成立。最后,通过反Specker原理将表观收敛与收敛联系起来。

英文摘要

The notions of provisional, negative, and apparent convergence to 0 are introduced. It is then shown that Markov's principle is equivalent, in Bishop-style constructive mathematics, to the statement `every decreasing sequence of real numbers provisionally convergent to 0 actually converges to 0', and that this equivalence holds with `provisionally' replaced by `negatively'. Finally, apparent convergence and convergence are related by means of the anti-Specker principle.

2606.08862 2026-06-09 astro-ph.HE 新提交

Disk reflection as the origin of the X-ray polarization of NGC 4151 with IXPE

IXPE观测的NGC 4151 X射线偏振起源于盘反射

E. Kammoun, M. Dovčiak, J. Podgorný, I. E. Papadakis, V. Binas-Valavanis, S. Bianchi, V. E. Gianolli, F. Ursini, J. A. García

AI总结 利用IXPE、XMM-Newton和NuSTAR数据,通过盘反射模型解释NGC 4151的X射线偏振,发现紧凑灯柱日冕和较大环面张角可同时解释偏振和宽带谱。

Comments Submitted to ApJ

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AI中文摘要

我们利用2022年和2024年两次长IXPE观测,结合同时的XMM-Newton和NuSTAR光谱,对近邻1型活动星系核NGC 4151进行了X射线光谱偏振研究。IXPE测量到4 keV以上偏振度约为6-7%,偏振角与射电喷流平行,并存在一个不同角度的明显低能成分,表明2-8 keV波段至少有两个偏振成分。先前的工作将硬X射线偏振解释为径向延伸的板状日冕的证据。这里我们测试另一种情景,即观测到的偏振主要由一个紧凑的灯柱状日冕照亮的吸积盘的相对论性反射产生。使用最近开发的模型,我们用灯柱加远处环面的几何结构拟合IXPE Stokes光谱,包括部分覆盖吸收和额外的软偏振幂律成分。我们发现数据要求较低的日冕高度($h<9\\,R_{\rm g}$,3σ)和较大的环面张角($>45^\circ$,3σ),而盘反射贡献了2-8 keV通量的约20%。软偏振成分只携带约1-5%的通量,但具有高偏振度(>10%)和约20°的偏振角。相同的配置对0.4-79 keV的XMM-Newton和NuSTAR光谱提供了可接受的拟合,表明紧凑日冕的盘再处理可以同时解释NGC 4151的偏振和宽带谱性质。

英文摘要

We present an X-ray spectro-polarimetric study of the nearby type-1 active galactic nucleus NGC 4151 using two long IXPE observations obtained in 2022 and 2024, supported by simultaneous XMM-Newton and NuSTAR spectroscopy. IXPE measures a polarization degree of $\sim 6-7\%$ above 4 keV, with a polarization angle parallel to the radio jet, and a distinct low-energy component with a different angle, indicating at least two polarized components in the $2-8$ keV band. Previous work interpreted the hard X-ray polarization as evidence for a radially extended slab-like corona. Here we test an alternative scenario in which the observed polarization is produced predominantly by relativistic reflection from an accretion disk illuminated by a compact, lamp-post-like corona. Using recently developed models, we fit the IXPE Stokes spectra with a lamp-post plus distant-torus geometry, including partial-covering absorption and an additional soft polarized power-law component. We find that the data require a low coronal height ($h<9\,R_{\rm g}$ at $3σ$) and a relatively large torus opening angle ($>45^\circ$ at 3$σ$), while the disk reflection contributes $\sim 20\%$ of the 2-8 keV flux. The soft polarized component carries only $\sim 1-5\%$ of the flux but has a high polarization degree ($>10\%$) and a polarization angle around $20^\circ$. The same configuration provides acceptable fits to the $0.4-79$ keV XMM-Newton and NuSTAR spectra, demonstrating that disk reprocessing by a compact corona can simultaneously account for both the polarization and broadband spectral properties of NGC 4151.

2606.08861 2026-06-09 math.AP 新提交

Boundedness and evolution rates for a quasilinear reaction-diffusion equation

一类拟线性反应扩散方程的有界性与演化速率

Razvan Gabriel Iagar, Marta Latorre, Ariel Sánchez

AI总结 研究N≥3维空间中指数1<p<m且σ<-2的拟线性反应扩散方程,证明初始条件满足一定衰减时解一致有界,并建立了紧支集数据正性集上界R(t)的扩张速率及外部区域的不同时间尺度。

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AI中文摘要

考虑以下拟线性反应扩散方程 $$ \partial_tu=\Delta u^m+(1+|x|)^\sigma u^p, \quad (x,t)\in\mathbb{R}^N\times(0,\infty), $$ 在维度$N\geq3$和指数范围$1<p<m$及$-\infty<\sigma<-2$中。我们证明,对于满足 $$ u_0\geq0, \quad u_0\not\equiv0, \quad \lim\limits_{|x|\to\infty}|x|^{-(\sigma+2)/(m-p)}u_0(x)=0 $$ 的初始条件$u_0$,相应柯西问题的解$u$保持一致有界: $$ C_1\leq \\|u(t)\\|_{\infty}\leq C_2, \quad t\in(0,\infty), $$ 其中$C_1$和$C_2$为正常数。在$p$的适当条件下,我们还建立了紧支集数据正性集上界$R(t)$的扩张速率,即 $$ At^\beta\leq R(t)\leq Bt^\beta, \quad \beta=-\frac{m-p}{\sigma(m-1)+2(p-1)}, $$ 以及外部集合中的\emph{不同时间尺度},即 $$ D_1t^{-\alpha}\leq u(x,t)\leq D_2t^{-\alpha}, \quad \alpha=\frac{\sigma+2}{\sigma(m-1)+2(p-1)}, \quad {\rm if} \\ |x|\geq Ct^\beta. $$ 这一有界性与作者先前关于$\sigma>-2$时解随$t\to\infty$增长的性质形成鲜明对比,说明了指数$\sigma=-2$的阈值特征。

英文摘要

We consider the following quasilinear reaction-diffusion equation $$ \partial_tu=Δu^m+(1+|x|)^σu^p, \quad (x,t)\in\mathbb{R}^N\times(0,\infty), $$ in dimension $N\geq3$ and in the range of exponents $1<p<m$ and $-\infty<σ<-2$. We prove that, for initial conditions $u_0$ satisfying $$ u_0\geq0, \quad u_0\not\equiv0, \quad \lim\limits_{|x|\to\infty}|x|^{-(σ+2)/(m-p)}u_0(x)=0, $$ the solution $u$ to the corresponding Cauchy problem remains uniformly bounded from above and below: $$ C_1\leq \|u(t)\|_{\infty}\leq C_2, \quad t\in(0,\infty), $$ for some positive constants $C_1$ and $C_2$. Under suitable conditions on $p$, we also establish the rate of expansion of the upper limit $R(t)$ of the positivity set for compactly supported data, that is, $$ At^β\leq R(t)\leq Bt^β, \quad β=-\frac{m-p}{σ(m-1)+2(p-1)}, $$ and a \emph{different time scale in outer sets}, that is $$ D_1t^{-α}\leq u(x,t)\leq D_2t^{-α}, \quad α=\frac{σ+2}{σ(m-1)+2(p-1)}, \quad {\rm if} \ |x|\geq Ct^β. $$ The boundedness is in striking contrast with the property of grow-up as $t\to\infty$ established in previous works by the authors for $σ>-2$, illustrating the character of threshold of the exponent $σ=-2$.