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2602.00506 2026-06-05 gr-qc astro-ph.CO hep-ph hep-th

Realization of quintom dark energy after DESI DR2 in Nieh-Yan modified teleparallel gravity

在Nieh-Yan修正的teleparallel引力论中实现quintom暗物质能量

Yuxuan Kang, Mingzhe Li, Changzhi Yi

AI总结 基于DESI DR2观测数据,研究quintom暗物质能量模型在Nieh-Yan修正teleparallel引力论中的实现,通过引入暗物质能量与Nieh-Yan密度的耦合,解决传统模型在穿越cosmological常数边界时的扰动不稳定性问题。

Comments 18 pages, 4 figures, accepted for publication in The European Physical Journal C

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AI中文摘要

最近的DESI合作组织观测表明,quintom暗物质能量模型受到偏好,即其方程状态在cosmological常数边界$w=-1$处演变。众所周知,具有单一完美流体或单一标量场最小耦合到爱因斯坦引力的模型在穿越时发展出扰动不稳定性,因此无法实现quintom场景。在本文中,我们提出了一种方法,通过在teleparallel引力论框架内考虑暗物质能量与Nieh-Yan密度的耦合,来克服这些模型的不稳定性问题。我们显示,通过这种耦合,背景演化不受影响,但暗物质能量扰动被从动态自由度中排除,从而避免了旧模型固有的困难。此外,Nieh-Yan耦合导致引力波的宇称破坏,这可以被视为该机制的明确预测。

英文摘要

Recent observations from the DESI Collaboration indicate a preference for quintom dark energy, i.e., its equation of state evolves across the cosmological constant boundary $w=-1$. It is well known that models with single perfect fluid or single scalar field minimally coupled to Einstein gravity develop perturbative instabilities around the crossing, thereby cannot realize the quintom scenario. In this paper, we propose a method to circumvent the instability problem of these models by considering the coupling of dark energy to the Nieh-Yan density within the framework of teleparallel gravity. We show that with this coupling the background evolution is not affected, but the dark energy perturbation is removed from the menu of dynamical degrees of freedom, thus avoiding the inherent difficulties in the old models. Furthermore, the Nieh-Yan coupling causes parity violation in gravitational waves, and this can be considered as a clear prediction of this mechanism.

2602.10103 2026-06-05 math.ST math.PR stat.TH

Minimax properties of gamma kernel density estimators under $L^p$ loss and $β$-Hölder smoothness of the target

gamma核密度估计在$L^p$损失和β-Holder光滑目标下的极小大性质

Frédéric Ouimet

AI总结 本文研究了在β-Hölder空间中,非修改的gamma核密度估计在L^p损失下的渐近行为,特别是在目标可能有有限有效或真实上端点但估计器本身未截断并将其支持视为[0,∞)的情况下。通过将有限端点作为函数类和风险定义中的分析工具,而非作为估计器的信息,选择的功能类使得目标密度在上端点处平滑地趋于零,从而隔离了原点处的行为并避免了额外的上端点泄漏偏差。证明了当(p,β)∈[1,3)×(0,2]或当3≤p<4且(p-3)/(p-2)<β≤2时,该估计器可以实现极小大率,而当p∈[4,∞)或β∈(2,∞)时则无法实现极小大。剩余区域{(p,β):3<p<4,0<β≤(p-3)/(p-2)}仍是一个开放问题。

Comments 37 pages, 3 figures

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AI中文摘要

本文考虑了在β-Hölder空间中,非修改的gamma核密度估计在L^p损失下的渐近行为,特别是在目标可能有有限有效或真实上端点但估计器本身未截断并将其支持视为[0,∞)的情况下。有限端点被用作函数类和风险定义中的分析工具,而非作为估计器的信息。功能类被选择使得目标密度在上端点处平滑地趋于零,从而隔离了原点处的行为并避免了额外的上端点泄漏偏差。证明了当(p,β)∈[1,3)×(0,2]或当3≤p<4且(p-3)/(p-2)<β≤2时,该估计器可以实现极小大率,而当p∈[4,∞)或β∈(2,∞)时则无法实现极小大。剩余区域{(p,β):3<p<4,0<β≤(p-3)/(p-2)}仍是一个开放问题。

英文摘要

This paper considers the asymptotic behavior in $β$-Hölder spaces, and under $L^p$ loss, of the non-modified gamma kernel density estimator introduced by Chen [Ann. Inst. Statist. Math. 52 (2000), 471-480] for the analysis of nonnegative data, in the situation where the target may have a finite effective or true upper endpoint but the estimator itself is left untruncated and treats the support as $[0,\infty)$. The finite endpoint is used as an analytical device in the definition of the function class and the risk, not as information supplied to the estimator. The functional classes are chosen so that the target density matches smoothly to zero at the upper endpoint, which isolates the behavior at the origin and avoids an additional upper-endpoint leakage bias. It is shown that this estimator can achieve the minimax rate asymptotically for a suitable choice of bandwidth whenever $(p,β)\in [1,3)\times(0,2]$, or whenever $3 \leq p < 4$ and $(p-3)/(p-2) < β\leq 2$. It is also shown that this estimator cannot be minimax when either $p\in [4,\infty)$ or $β\in (2,\infty)$. The remaining region $\left\{(p,β): 3 < p < 4,\ 0 < β\leq (p-3)/(p-2)\right\}$ is an open case.

2602.07481 2026-06-05 cond-mat.supr-con cond-mat.mtrl-sci physics.app-ph

Complete electronic phase diagram and enhanced superconductivity in fluorine-doped PrFeAsO1-xFx

氟掺杂PrFeAsO1-xFx的完整电子相图及增强的超导性

Priya Singh, Konrad Kwatek, Tatiana Zajarniuk, Taras Palasyuk, Cezariusz Jastrzębski, A. Szewczyk, Shiv J. Singh

AI总结 本研究通过系统研究PrFeAsO1-xFx在全氟掺杂范围内的情况,构建了该系统的首个完整电子相图,揭示了从非超导基化合物到富氟极限的演变过程,发现了一个广域的超导区域,并发现最大超导转变温度达到52.3 K,比之前报道的Pr1111系统高约5 K。

Comments 33 pages, 9 figures

Journal ref Journal of Alloys and Compounds 1072 (2026) 188942

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AI中文摘要

建立REFeAsO(RE=稀土,RE1111)铁基超导体的完整电子相图一直面临实验挑战。在这里,我们报告了对PrFeAsO1-xFx在全氟掺杂范围0到1的系统研究,并构建了该系统的首个完整电子相图。从非超导基化合物到富氟极限的演变揭示了一个广域的 dome 形状超导区域。结构精修显示随着氟含量(x)的增加,晶格收缩系统性地发生,通过拉曼光谱通过Pr(A1g)声子模式变软和Fe(B1g)模式变硬得到证实,确认了氟在氧位的有效掺杂。最大超导转变温度(Tc)达到52.3 K,大约比之前报道的Pr1111系统的5 K高。磁输运测量得到的上临界磁场Hc2(0)超过100 T,而电阻转变变宽分析揭示了热激活磁通流,从单涡旋到集体钉扎区域的转变。比热测量显示减少的跃迁跳跃deltaC/γTc < 1.43,反映了强超导波动和多带配对。这些结果建立了清晰的结构-性质相关性,并为Pr1111系统的整个掺杂范围提供了统一的超导描述。

英文摘要

Establishing a complete electronic phase diagram for REFeAsO (RE = rare earth, RE1111) ironbased superconductors has remained experimentally challenging. Here, we report a systematic investigation of PrFeAsO1-xFx over the full nominal fluorine-doping range 0 to 1 and construct the first comprehensive electronic phase diagram for this system. The evolution from the nonsuperconducting parent compound to the fluorine-rich limit reveals a broad dome shaped superconducting region. Structural refinement demonstrates a systematic lattice contraction with increasing fluorine content (x), corroborated by Raman spectroscopy through softening of the Pr(A1g) phonon mode and hardening of the Fe(B1g) mode, confirming effective fluorine incorporation at the oxygen sites. The maximum superconducting transition temperature (Tc) reaches up to 52.3 K, approximately 5 K higher than previous reports for Pr1111. Magnetotransport measurements yield large upper critical fields Hc2(0) exceeding 100 T, while analysis of resistive transition broadening reveals thermally activated flux flow with a crossover from single-vortex to collective pinning regimes. Specific-heat measurements exhibit a reduced jump deltaC/γTc < 1.43, reflecting strong superconducting fluctuations and multiband pairing. These results establish clear structure property correlations and provide a unified description of superconductivity across the entire doping range of the Pr1111 system.

2512.03658 2026-06-05 cond-mat.supr-con

Double-Bridge Mechanism for Enhancing Tc in Oxide Superconductors

双桥机制用于增强氧化物超导体的临界温度

Jun-jie Shi, Juan Du, Yao-hui Zhu

AI总结 本文提出了一种双桥机制,通过增强离子键驱动的O/Cu桥接配对,显著提高氧化物超导体的临界温度,并揭示了关键的桥II Cu/O介导的配对吸引力,克服了直接库仑排斥,驱动预形成库珀对的相干玻色-爱因斯坦凝聚。

Comments 7 pages, 5 figures

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AI中文摘要

我们提出了一种新的双桥机制,以显著提高离子氧化物超导体的临界温度。基于我们最近提出的离子键驱动的O/Cu桥接(桥I)配对e$^-$-O-e$^-$/h$^+$-Cu-h$^+$,在伪间隙相(Tc<T<T*)中形成的配对,我们揭示了关键的桥II Cu/O介导的配对吸引力,克服了直接库仑排斥并驱动预形成库珀对的相干玻色-爱因斯坦凝聚(BEC)。在BEC框架(方程(3))下,Tc遵循Uemura缩放(n_{ m pair}^{ m 3D})^{2/3}/m_{ m pair}^*或n_{ m pair}^{ m 2D}/m_{ m pair}^*)并随吸引散射长度a<0线性增加。增强桥II吸引力、最小化m_{ m pair}^*和优化n_{ m pair}^{ m 3D}是提高Tc的关键。这种双桥机制统一了室温下的eV尺度强配对和BEC,提供了一条通往更高Tc的通用途径,并指导了下一代超导体的设计。

英文摘要

We propose a new double-bridge mechanism to significantly enhance $T_c$ in ionic oxide superconductors. Based on our recently proposed ionic-bond-driven O/Cu-bridged (bridge-I) pairing e$^-$-O-e$^-$/h$^+$-Cu-h$^+$ formed in the pseudogap phase ($T_c<T<T^*$), we reveal a key bridge-II Cu/O-mediated inter-pair attraction that overcomes direct Coulomb repulsion and drives coherent Bose-Einstein condensation (BEC) of preformed Cooper pairs. Within the BEC framework (Eq.(3)), $T_c$ follows the Uemura scaling $(n_{\rm pair}^{\rm 3D})^{2/3}/m_{\rm pair}^*$ or $n_{\rm pair}^{\rm 2D}/m_{\rm pair}^*$ and increases linearly with the attractive scattering length $a<0$. Strengthening bridge-II attraction, minimizing $m_{\rm pair}^*$, and optimizing $n_{\rm pair}^{\rm 3D}$ are the key to maximizing $T_c$. This double-bridge mechanism unifies the \textbf{eV-scale} strong pairing at room temperature and BEC, provides a universal route toward higher $T_c$, and guides the design of next-generation superconductors.

2602.06303 2026-06-05 math.AP

Global weak solutions with higher regularity to the two-dimensional isentropic compressible Navier-Stokes and magnetohydrodynamic equations with far-field vacuum and unbounded density

二维等熵可压缩纳维-斯托克斯与磁流体动力学方程在远场真空和无界密度下的全局弱解及其更高正则性

Shuai Wang, Xin Zhong

AI总结 本文研究了二维等熵可压缩纳维-斯托克斯与磁流体动力学方程在远场真空和无界密度下的全局弱解的存在性,通过构造具有合适初始能量的解,扩展了之前半平面情况的研究,并将Hoff和Suen-Hoff的工作推广到全平面MHD耦合情况。

Comments 28 pages. This article is a extended version of work related to arXiv:2601.11852, with overlapping code and implementation details. arXiv admin note: substantial text overlap with arXiv:2601.11852

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AI中文摘要

我们建立了在全平面上,具有合适小初始能量的等熵可压缩纳维-斯托克斯与磁流体动力学(MHD)方程的一类全局弱解的存在性。所构造的解允许远场真空和无界密度。此外,这些解具有介于Lions-Feireisl有限能量弱解和Hoff框架之间的中间正则性。这特别扩展了我们之前半平面情况(arXiv:2601.11852)到全平面MHD耦合情况,并通过允许真空状态和无界密度,将Hoff(Comm. Pure Appl. Math. 55 (2002), pp. 1365-1407)和Suen和Hoff(Arch. Ration. Mech. Anal. 205 (2012), pp. 27-58)的工作推广。我们的分析基于一个新的视角,利用密度的空问可积性以及由此产生的压力可积性,以及MHD系统的特定结构。

英文摘要

We establish the global existence of a class of weak solutions to the isentropic compressible Navier-Stokes and magnetohydrodynamic (MHD) equations on the whole plane under a suitably small initial energy. The solutions constructed here admit far-field vacuum and unbounded densities. Moreover, they possess an intermediate regularity regime between the finite-energy weak solutions of Lions-Feireisl and the framework of Hoff. This particularly extends our previous half-plane case with Dirichlet boundary conditions (arXiv:2601.11852) to the whole-plane MHD coupling, and we also generalize the works of Hoff (Comm. Pure Appl. Math. 55 (2002), pp. 1365-1407) and Suen and Hoff (Arch. Ration. Mech. Anal. 205 (2012), pp. 27-58) by allowing vacuum states and unbounded density. Our analysis lies in a new perspective that exploits the spatial integrability of the density and the resulting integrability of the pressure, together with the specific structure of the MHD system.

2602.05545 2026-06-05 cond-mat.soft cond-mat.dis-nn cond-mat.mtrl-sci

Probing Anharmonic and Heterogeneous Carrier Dynamics Across Sublattice Melting in a Minimal Model Superionic Conductor

探测超离子导体中子格子熔化中的非谐振与异质载流子动力学

Sucharita Niyogi, Takenobu Nakamura, Genki Kobayashi, Yasunobu Ando, Takeshi Kawasaki

AI总结 本文研究了超离子导体中子格子熔化和快速离子传输的微观起源,提出了一种化学中性且简化的二元模型,通过分子动力学模拟揭示了三种动力学阶段,并展示了通过调节密度控制子格子熔化的方法,为设计机械稳定的超离子导体提供了统一的微观基础。

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AI中文摘要

尽管已有数十年的研究,超离子导体中子格子熔化和快速离子传输的微观起源仍然不清楚。本文引入了一种化学中性且简化的二元模型,由一个由短程立体排斥稳定化的刚性宿主晶格和一个通过长程威根型力相互作用的柔软载流子子晶格组成。这种对比自然产生了不同的熔化温度和一个中间子晶格熔化相,在此相中载流子成为流体状而宿主仍保持晶体状。分子动力学模拟识别出三种动力学阶段——晶体态、子晶格熔化态和完全熔化态,这些阶段通过扩散性、结构相关性和动力学异质性上的明显变化来标记。在接近子晶格熔化时,载流子运动呈现强烈的非谐振性和空间异质性,超出了平均场跃迁描述。通过调节密度,我们证明子晶格熔化可以连续控制,建立了晶格软性、非谐振性和集体离子传输之间的直接联系。与传统长程库仑模型的比较确认了我们的最小模型能够再现超离子性的关键动力学特征,为设计机械稳定的超离子导体提供了统一的微观基础。

英文摘要

Despite decades of research, the microscopic origin of sublattice melting and fast ion transport in superionic conductors remains elusive. Here, we introduce a chemically neutral minimal binary model consisting of a rigid host lattice stabilized by short-range steric repulsion and a soft carrier sublattice interacting via long-range Wigner-type forces. This contrast naturally produces distinct melting temperatures and an intermediate sublattice-melting phase in which carriers become fluidlike while the host remains crystalline. Molecular dynamics simulations identify three dynamical regimes-crystalline, sublattice-melt, and fully molten-marked by sharp changes in diffusivity, structural correlations, and dynamical heterogeneity. Near sublattice melting, carrier motion is strongly anharmonic and spatially heterogeneous, beyond mean-field hopping descriptions. By tuning the density, we demonstrate that sublattice melting can be continuously controlled, establishing a direct link between lattice softness, anharmonicity, and collective ion transport. Comparison with conventional long-range Coulombic models confirms that our minimal model reproduces the key dynamical signatures of superionicity, providing a unified microscopic foundation for designing mechanically robust superionic conductors.

2511.14224 2026-06-05 cs.SE

Knowledge Matters: Injecting Project and Testing Knowledge into LLM-based Unit Test Generation

知识很重要:将项目和测试知识注入基于大语言模型的单元测试生成

Anji Li, Mingwei Liu, Zhenxi Chen, Zheng Pei, Zike Li, Dekun Dai, Yanlin Wang, Zibin Zheng

AI总结 本文提出KTester框架,通过整合项目特定知识和测试领域知识,提升基于大语言模型的单元测试生成能力,实验表明其在多个关键指标上优于现有方法,提高了测试通过率和覆盖率,且生成的测试更易读易维护。

Comments Accepted at the 48th International Conference on Software Engineering(ICSE 2026),13 pages, 11 figures

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AI中文摘要

使用大型语言模型(LLMs)的自动单元测试生成具有巨大潜力,但在真实世界项目中往往难以生成既正确又可维护的测试。本文提出了KTester,一种新的框架,通过整合项目特定知识和测试领域知识来增强LLM基于的测试生成。我们的方法首先通过静态分析提取项目结构和使用知识,为模型提供丰富的上下文。然后,它采用测试领域知识引导的测试用例设计和测试方法生成分离,结合多视角提示策略,引导LLM考虑多样的测试启发式方法。生成的测试遵循结构化模板,提高了清晰度和可维护性。我们在多个开源项目上评估KTester,将其与最先进的基于LLM的基线方法进行比较,使用自动正确性和覆盖率指标,以及评估可读性和可维护性的人工研究。结果表明,KTester在六个关键指标上显著优于现有方法,比最强基线提高了5.69%的执行通过率和8.83%的行覆盖率,同时所需时间和生成的测试用例更少。人工评估者也认为KTester生成的测试在正确性、可读性和可维护性方面评分更高,证实了我们知识驱动框架的实用优势。

英文摘要

Automated unit test generation using large language models (LLMs) holds great promise but often struggles with generating tests that are both correct and maintainable in real-world projects. This paper presents KTester, a novel framework that integrates project-specific knowledge and testing domain knowledge to enhance LLM-based test generation. Our approach first extracts project structure and usage knowledge through static analysis, which provides rich context for the model. It then employs a testing-domain-knowledge-guided separation of test case design and test method generation, combined with a multi-perspective prompting strategy that guides the LLM to consider diverse testing heuristics. The generated tests follow structured templates, improving clarity and maintainability. We evaluate KTester on multiple open-source projects, comparing it against state-of-the-art LLM-based baselines using automatic correctness and coverage metrics, as well as a human study assessing readability and maintainability. Results demonstrate that KTester significantly outperforms existing methods across six key metrics, improving execution pass rate by 5.69% and line coverage by 8.83% over the strongest baseline, while requiring less time and generating fewer test cases. Human evaluators also rate the tests produced by KTester significantly higher in terms of correctness, readability, and maintainability, confirming the practical advantages of our knowledge-driven framework.

2602.06169 2026-06-05 cond-mat.quant-gas

Mobile impurity interacting with a Hubbard chain and the role of Friedel oscillations

移动杂质与Hubbard链的相互作用及Friedel振荡的作用

Felipe Isaule, Abel Rojo-Francàs, Duc Tuan Hoang, Thomás Fogarty, Thomas Busch, Bruno Juliá-Díaz

AI总结 研究移动杂质与费米子浴的相互作用,发现强排斥和强吸引杂质均与费米子空穴发生相分离,并通过Friedel振荡导致杂质密度出现振荡模式。

Comments Accepted version. 17 pages, 16 figures

Journal ref Phys. Rev. B 113, 224303 (2026)

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AI中文摘要

本工作考察了移动杂质与少量一维开放晶格中少量自旋向上和自旋向下费米子浴的相互作用。我们利用精确对角化方法研究系统的基态性质,其中系统由三组分费米Hubbard哈密顿量建模。我们发现除了强排斥杂质与浴之间的标准相分离外,强吸引杂质也由于粒子-空穴对称性与费米子空穴发生相分离。此外,我们发现杂质在中间吸引和排斥的浴-杂质相互作用下,其密度会表现出由有限大小费米子浴中的Friedel振荡诱导的振荡模式。这种丰富的杂质行为可能通过费米子超冷混合物在光学晶格中进行探测。

英文摘要

This work examines a mobile impurity interacting with a bath of a few spin-$\uparrow$ and spin-$\downarrow$ fermions in a small one-dimensional open lattice system. We study ground-state properties using the exact diagonalization method, where the system is modeled by a three-component Fermi Hubbard Hamiltonian. We find that in addition to the standard phase separation between a strongly repulsive impurity and the bath, a strongly-attractive impurity also phase separates with the fermionic holes due to the particle-hole symmetry. Furthermore, we find that the impurity can show an oscillatory pattern in its density for intermediate attractive and repulsive bath-impurity interactions, which are induced by Friedel oscillations in the finite-size fermionic bath. This rich behavior of the impurity could be probed with fermionic ultracold mixtures in optical lattices.

2509.01392 2026-06-05 math.FA math.AP math.CA

Birkhoff-Kellogg type results in product spaces and their application to differential systems

产品空间中的Birkhoff-Kellogg型结果及其在微分系统中的应用

Alessandro Calamai, Gennaro Infante, Jorge Rodríguez-López

AI总结 本文在产品空间中提出了一种新的Birkhoff-Kellogg不变方向定理版本,研究了算子系统中组件特征值的存在性,而非传统标量特征值,并展示了特征向量的非平凡性和规范局部化性质,这些性质在非线性微分方程特征值问题中提供了定性解的性质,通过两个PDE和ODE系统的例子进行了说明。

Comments 15

Journal ref J. Fixed Point Theory Appl. 28, 37 (2026)

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AI中文摘要

我们提供了一个广为人知的Birkhoff-Kellogg不变方向定理在产品空间中的新版本。我们的结果关注于算子系统,并给出了具有所有组件非平凡且由其范数局部化的组件特征值的存在性,而不是传统情况下的标量特征值。我们还展示了,当应用于微分方程的非线性特征值问题时,这种特征向量的局部化性质反过来提供了解的定性性质。这在两个PDE和ODE系统的背景下进行了说明。我们通过两个明确的例子展示了我们的理论结果的应用性。

英文摘要

We provide a new version of the well-known Birkhoff-Kellogg invariant-direction Theorem in product spaces. Our results concern operator systems and give the existence of component-wise eigenvalues, instead of scalar eigenvalues as in the classical case, that have corresponding eigenvectors with all components nontrivial and localized by their norm. We also show that, when applied to nonlinear eigenvalue problems for differential equations, this localization property of the eigenvectors provides, in turn, qualitative properties of the solutions. This is illustrated in two contexts of systems of PDEs and ODEs. We show the applicability of our theoretical results with two explicit examples.

2602.04874 2026-06-05 physics.app-ph

Epitaxial growth optimization, measurement and theoretical analysis of strain-compensated QCL grown on (511)A InP

外延生长优化,(511)A InP上应变补偿量子点激光器的测量与理论分析

Alessio Cargioli, Mattias Beck, Jerome Faist

AI总结 本文研究了在(511)A InP基板上生长应变补偿量子点激光器(QCL)的条件,通过AFM和XRD测量发现调节砷化氢流量和正确调整III/V比例是获得高质量材料的关键,并报告了首个在该平台上实现激光的器件,其电流密度阈值为1.34 kA/cm²,斜率效率为1.1 W/A,但结果不如(100)参考。最后发现(511)A光谱出现7%的红移,归因于暴露(111)方向的杂质散射。

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AI中文摘要

界面粗糙度散射是实现高性能量子点激光器(QCL)的重要限制因素。根据最近的研究结果,我们研究了在(511)A InP基板上生长约4.6 μm波长的应变补偿QCL的生长条件,使用AFM和XRD测量。我们发现调节砷化氢流量和正确调整III/V比例是获得高质量材料的关键。我们报告了首个在该平台上实现激光的器件,其电流密度阈值为1.34 kA/cm²,斜率效率为1.1 W/A,但结果不如(100)参考。最后,我们发现(511)A光谱出现7%的红移,我们将其归因于由于暴露(111)方向的杂质散射。我们通过验证由于应变沿非平凡方向导致的CBO和有效电子质量的变化无法引起这种偏移,从而验证了这一说法,通过使用扩展到任意生长方向的k-p方法。

英文摘要

Interface roughness scattering is an important limiting factor for achieving high performance Quantum Cascade Lasers. Following recent results, we study the growth conditions for a strain-compensated QCL emitting around 4.6 μm grown on a (511)A InP substrate using AFM and XRD measurements. We find that modulating the arsenic flux and correctly tailoring the III/V ratio is fundamental to achieve a good quality material. We report the first lasing device on such a platform with a current density threshold of 1.34 kA/cm2 and a slope efficiency of 1.1 W/A, which result suboptimal compared to the (100) reference. Finally, we find a 7% redshift of the (511)A spectrum which we attribute to an impurity scattering due to the increased incorporation along the exposed (111) direction. We validate this statement by verifying that the change in CBO and effective electron mass due to strain along a non-trivial direction cannot cause such a shift by using the k-p method generalized to arbitrary growth directions

2602.03765 2026-06-05 quant-ph cond-mat.stat-mech

Accelerating qubit reset through the Mpemba effect

通过迈佩尔效应加速量子比特重置

Théo Lejeune, Miha Papič, John Goold, Felix C. Binder, François Damanet, Mattia Moroder

AI总结 本文提出利用迈佩尔效应加速量子比特重置,通过单个纠缠两量子比特门将局部单量子比特相干性转换为快速衰减的全局两量子比特相干性,从而加快量子比特向基态的弛豫过程,实验验证了该方法在实际参数下的有效性。

Comments 19 pages, 9 figures

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AI中文摘要

被动量子比特重置是量子信息处理中的关键基础操作,其中量子比特通过自然耗散松弛到基态进行初始化,而无需主动控制或反馈。然而,被动重置的时间尺度远长于门操作和测量的时间尺度,成为算法执行的瓶颈。本文表明,通过利用迈佩尔效应,即热系统比冷系统冷却更快,可以克服这一限制。在相干时间超过能量弛豫时间(T₂ > T₁)的 regime 中,我们提出基于单个纠缠两量子比特门的简单协议,将局部单量子比特相干性转换为快速衰减的全局两量子比特相干性,从而消除其与最慢衰减的李维利昂模式的重叠,使量子比特显著更快地松弛到基态。对于实际参数,我们发现该协议可将重置时间比标准被动重置减少高达 50%。我们分析了该协议在非马尔可夫噪声、不完美的相干控制和有限温度下的鲁棒性,发现加速的重置在广泛的实际误差源下持续存在。最后,我们展示了在 IQM 超导量子处理器上的实验实现。我们的结果展示了如何利用类似迈佩尔效应的加速弛豫作为快速准确量子比特初始化的实用工具。

英文摘要

Passive qubit reset is a key primitive for quantum information processing, whereby qubits are initialized by allowing them to relax to their ground state through natural dissipation, without the need for active control or feedback. However, passive reset occurs on timescales that are much longer than those of gate operations and measurements, making it a significant bottleneck for algorithmic execution. Here, we show that this limitation can be overcome by exploiting the Mpemba effect, originally indicating the faster cooling of hot systems compared to cooler ones. Focusing on the regime where coherence times exceed energy relaxation times ($T_2 > T_1$), we propose a simple protocol based on a single entangling two-qubit gate that converts local single-qubit coherences into fast-decaying global two-qubit coherences. This removes their overlap with the slowest decaying Liouvillian mode and enables a substantially faster relaxation to the ground state. For realistic parameters, we find that our protocol can reduce reset times by up to $50\%$ compared to standard passive reset. We analyze the robustness of the protocol under non-Markovian noise, imperfect coherent control and finite temperature, finding that the accelerated reset persists across a broad range of realistic error sources. Finally, we present an experimental implementation of our protocol on an IQM superconducting quantum processor. Our results demonstrate how Mpemba-like accelerated relaxation can be harnessed as a practical tool for fast and accurate qubit initialization.

2602.03032 2026-06-05 astro-ph.HE

How Distance Affects GRB Prompt Emission Measurements

距离如何影响GRB瞬时辐射测量

Michael J. Moss, Amy Y. Lien, S. Bradley Cenko, Sylvain Guiriec, Craig B. Markwardt

AI总结 研究探讨了Gamma-Ray Burst (GRB)瞬时辐射测量如何受到源距离增加的影响,通过模拟高红移GRB的观测结果,发现低信噪比导致的背景主导效应使测量的持续时间低估,且高红移GRB的平均持续时间和能量变化与'冰山尖端'效应一致。

Comments 19 pages, 14 figures

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AI中文摘要

我们研究了Gamma-Ray Burst (GRB)瞬时辐射测量如何受到源距离增加的影响。我们选取了26个红移z<1的明亮GRB,由Swift卫星上的 Burst Alert Telescope (BAT)观测,并模拟了如果GRB位于更高红移时BAT会观测到的结果。我们使用贝叶斯块方法测量了模拟的伽马射线信号的持续时间,并计算了封装的流量和峰值流量。正如预期的那样,我们发现几乎所有模拟高红移GRB的持续时间(流量)测量值都比其真实持续时间(能量)短,这是因为低信噪比的辐射完全被背景主导,即所谓的'冰山尖端'效应。这种效应强烈依赖于源光曲线的轮廓和强度。由于GRB光曲线的特殊性,测量的持续时间随红移变化没有共同的行为。我们将我们的合成高红移(即z>3)GRB与72个观测到的高红移爆发样本进行了比较,发现这两个样本并不与来自同一潜在种群不一致。我们得出结论:(i)由Swift/BAT观测的高红移GRB的瞬时辐射持续时间(流量)最可能是低估,有时低估幅度为几十倍(约2倍);(ii)随着红移增加,平均GRB瞬时辐射持续时间和流量的变化与'冰山尖端'效应一致。

英文摘要

We investigated how Gamma-Ray Burst (GRB) prompt emission measurements are affected by increasing distance to the source. We selected a sample of 26 bright GRBs with measured redshifts $z<1$ observed by the Burst Alert Telescope (BAT) on board the Neil Gehrels Swift Observatory (Swift) and simulated what BAT would have observed if the GRBs were at larger redshifts. We measured the durations of the simulated gamma-ray signals using a Bayesian block approach and calculated the enclosed fluences and peak fluxes. As expected, we found that almost all durations (fluences) measured for simulated high-$z$ GRBs were shorter (less) than their true durations (energies) due to low signal-to-noise ratio emission becoming completely dominated by background, i.e., the ``tip-of-the-iceberg'' effect. This effect strongly depends on the profile and intensity of the source light curve. Due to the uniqueness of GRB light curves, there is no common behavior in the evolution of measured durations with redshift. We compared our synthetic high-$z$ (i.e., $z>3$) GRBs to a sample of 72 observed high-$z$ bursts and found that the two samples were not inconsistent with being drawn from the same underlying population. We conclude that: (i) prompt emission durations (fluences) of high-$z$ GRBs observed by Swift/BAT are most likely underestimations, sometimes by factors of $\sim$several tens ($\sim2$), and (ii) changes in the average GRB prompt emission duration and fluence with increasing redshift are consistent with the tip-of-the-iceberg effect.

2602.02987 2026-06-05 cs.DC math.OC

Large-Scale LLM Inference with Heterogeneous Workloads: Prefill-Decode Contention and Asymptotically Optimal Control

大规模LLM推理与异构工作负载:Prefill-Decode竞争及渐进最优控制

Ruihan Lin, Zezhen Ding, Zean Han, Jiheng Zhang

AI总结 本文研究了大规模LLM推理中异构工作负载下的Prefill-Decode竞争问题,提出了一种随机控制框架,通过多类多服务器队列网络模型,实现了渐进最优的资源分配与调度策略。

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AI中文摘要

大规模语言模型(LLMs)正迅速成为企业应用的关键基础设施,推动了对基于GPU的推理服务前所未有的需求。LLM推理具有两阶段性质:计算密集的prefill阶段处理用户输入,随后是内存受限的decode阶段生成输出token。当这两个阶段共享GPU资源时,prefill任务会限制同时decode的处理速度,产生状态依赖的竞争。这种竞争进一步复杂化于工作负载异质性,因为不同应用表现出截然不同的输入和输出长度。我们开发了一个随机控制框架,用于在大规模GPU集群上调度异构LLM工作负载。我们将LLM推理建模为具有状态依赖服务速率的多类多服务器排队网络,基于经验迭代时间测量。我们分析了该系统的流体近似,并解决了描述最优资源分配的稳态线性规划。我们设计了门控和路由策略,用于调节prefill准入和decode路由,并证明这些策略在大量GPU极限下在捆绑和分离token定价方案下都是渐进最优的。我们进一步扩展该框架,以纳入服务等级指标(SLIs)如延迟和公平性,提供了一种受限调度的一般方法。数值实验基于经验迭代时间数据证明,我们的策略优于标准服务启发式方法。

英文摘要

Large Language Models (LLMs) are rapidly becoming critical infrastructure for enterprise applications, driving unprecedented demand for GPU-based inference services. A key operational challenge arises from the two-phase nature of LLM inference: a compute-intensive \emph{prefill} phase that processes user input, followed by a memory-bound \emph{decode} phase that generates output tokens. When these phases share GPU resources, prefill tasks throttle the processing speed of concurrent decodes, creating state-dependent contention. This contention is further complicated by workload heterogeneity, as different applications exhibit vastly different input and output lengths. We develop a stochastic control framework for scheduling heterogeneous LLM workloads across large GPU clusters. We formulate LLM inference as a multiclass many-server queueing network with state-dependent service rates, grounded in empirical iteration-time measurements. We analyze the fluid approximation of this system and solve steady-state linear programs that characterize optimal resource allocation. We design gate-and-route policies that regulate prefill admission and decode routing, and prove that they are asymptotically optimal in the many-GPU limit under both bundled and separate token-pricing schemes. We further extend the framework to incorporate Service Level Indicators (SLIs) such as latency and fairness, providing a general approach to constrained scheduling. Numerical experiments calibrated to empirical iteration-time data demonstrate that our policies outperform standard serving heuristics.

2602.00898 2026-06-05 cs.GR cs.DC

Fast Sparse Matrix Permutation for Mesh-Based Direct Solvers

基于网格的直接求解器的快速稀疏矩阵置换

Behrooz Zarebavami, Ahmed H. Mahmoud, Ana Dodik, Changcheng Yuan, Serban D. Porumbescu, John D. Owens, Maryam Mehri Dehnavi, Justin Solomon

AI总结 本文提出了一种针对三角网格产生的线性系统优化的快速稀疏矩阵置换算法,通过放松传统分区和分离优化要求,提高置换效率和消除树构建效率,从而在CPU和GPU上实现更高效的稀疏Cholesky求解器。

Comments SIGGRAPH 2026

Journal ref In Proceedings of the SIGGRAPH 2026 Conference Papers, SIGGRAPH Conference Papers '26, New York, NY, USA, July 2026

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AI中文摘要

我们提出了一种针对三角网格产生的线性系统优化的快速稀疏矩阵置换算法。我们的方法生成类似嵌套分解的置换,同时显著减少置换运行时间开销。与强制严格平衡和分离最优性不同,该算法有意放松这些设计决策,以优先考虑快速分区和高效的消除树构建。我们的方法将置换分解为基于补丁的局部顺序和紧凑的商图顺序分离,保留稀疏Cholesky因子化所需的基本结构,同时避免其最昂贵的部分。我们将该算法集成到供应商维护的稀疏Cholesky求解器中,适用于CPU和GPU。在一系列图形应用中,包括单次因子化和重复因子化,我们的方法将置换时间减少并提高了稀疏Cholesky求解性能,最高提升达6.27倍。我们的代码可在https://github.com/BehroozZare/fast-permute上获得。

英文摘要

We present a fast sparse matrix permutation algorithm tailored to linear systems arising from triangle meshes. Our approach produces nested-dissection-style permutations while significantly reducing permutation runtime overhead. Rather than enforcing strict balance and separator optimality, the algorithm deliberately relaxes these design decisions to favor fast partitioning and efficient elimination-tree construction. Our method decomposes permutation into patch-level local orderings and a compact quotient-graph ordering of separators, preserving the essential structure required by sparse Cholesky factorization while avoiding its most expensive components. We integrate our algorithm into vendor-maintained sparse Cholesky solvers on both CPUs and GPUs. Across a range of graphics applications, including single factorizations and repeated factorizations, our method reduces permutation time and improves the sparse Cholesky solve performance by up to 6.27x. Our code is available at https://github.com/BehroozZare/fast-permute.

2602.00525 2026-06-05 quant-ph

First-Principles Optical Descriptors and Hybrid Classical-Quantum Classification of Er-Doped CaF$_2$

基于第一原理的光学描述符和铒掺杂CaF₂的混合经典-量子分类

David Angel Alba Bonilla, Kerem Yurtseven, Krishan Sharma, Ragunath Chandrasekharan, Muhammad Khizar, Alireza Alipour, Dennis Delali Kwesi Wayo

AI总结 本文提出了一种结合第一原理光学描述符和经典-量子机器学习的方法,用于区分纯CaF₂和铒掺杂CaF₂,通过密度泛函理论和线性响应时间依赖密度泛函理论计算光学特性,并利用支持向量机和量子支持向量机进行分类,展示了掺杂诱导的光学指纹在近-term量子学习模型中的鲁棒性。

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AI中文摘要

我们提出了一种融合物理信息的经典-量子机器学习框架,用于利用第一原理光学描述符区分纯CaF₂和铒掺杂CaF₂。通过氟石结构(a=5.46~Å)构建了有限的Ca₈F₁₆和Ca₇ErF₁₆簇,并使用GPAW代码进行密度泛函理论(DFT)和线性响应时间依赖DFT(LR-TDDFT)计算。通过LCAO模式进行几何优化,使用DZP基组和PBE交换-关联泛函,随后进行实空间有限差分基态计算,网格间距h=0.30~Å和N_bands=N_occ+20。通过Casida形式式获得至10 eV的光学激发,并利用高斯展宽(σ=0.1-0.2 eV)转换为连续吸收光谱。从每个系统1,589个能量解析点中提取了包括过渡能量E、消光系数κ和吸收系数α在内的物理可解释描述符。经典RBF核支持向量机(SVM)达到测试准确率(ACC)为0.983和ROC-AUC为0.999。量子支持向量机(QSVM)在状态矢量和嘈杂模拟器上分别达到准确率0.851和0.817,而在IBM量子硬件上执行时,在有限射次和退相干约束下达到测试切片准确率0.733。一个具有3量子位特征图和深度4的量子神经网络(QNN)达到测试准确率0.93和AUC 0.96。结果表明,掺杂诱导的光学指纹形成一个稳健、基于物理的特征空间,用于评估近-term量子学习模型相对于强经典基线的基准。

英文摘要

We present a physics-informed classical-quantum machine learning framework for discriminating pristine CaF$_2$ from Er-doped CaF$_2$ using first-principles optical descriptors. Finite Ca$_8$F$_{16}$ and Ca$_7$ErF$_{16}$ clusters were constructed from the fluorite structure (a=5.46~$Å$) and treated using density functional theory (DFT) and linear-response time-dependent DFT (LR-TDDFT) within the GPAW code. Geometry optimization was performed in LCAO mode with a DZP basis and PBE exchange-correlation functional, followed by real-space finite-difference ground-state calculations with grid spacing h=0.30~$Å$ and N$_{bands}$=N$_{occ}$+20. Optical excitations up to 10~eV were obtained via the Casida formalism and converted into continuous absorption spectra using Gaussian broadening ($σ$=0.1-0.2~eV). From 1,589 energy-resolved points per system, physically interpretable descriptors including transition energy $E$, extinction coefficient $κ$, and absorption coefficient $α$ were extracted. A classical RBF-kernel support vector machine (SVM) achieves a test accuracy (ACC) of 0.983 and ROC-AUC of 0.999. Quantum support vector machines (QSVMs) evaluated on statevector and noisy simulators reach accuracies of 0.851 and 0.817, respectively, while execution on IBM quantum hardware yields a test-slice accuracy of 0.733 under finite-shot and decoherence constraints. A hybrid quantum neural network (QNN) with a 3-qubit feature map and depth-4 ansatz achieves a test accuracy of 0.93 and AUC of 0.96. Results here demonstrate that dopant-induced optical fingerprints form a robust, physically grounded feature space for benchmarking near-term quantum learning models against strong classical baselines.

2509.00406 2026-06-05 cs.GR

Locality-Aware Automatic Differentiation on the GPU for Mesh-Based Computations

基于GPU的局部感知自动微分用于基于网格的计算

Ahmed H. Mahmoud, Rahul Goel, Jonathan Ragan-Kelley, Justin Solomon

AI总结 本文提出了一种基于GPU的自动微分系统,用于在三角网格上定义的函数,利用网格计算中的局部性和稀疏性。系统通过每个元素的前向模式自动微分来评估导数,将所有计算限制在寄存器和共享内存中,并直接在GPU上组装全局梯度、稀疏雅可比矩阵和稀疏Hessian矩阵。通过避免全局计算图、中间缓冲区和设备-主机同步,该方法减少了内存流量,并在静态和动态变化的稀疏性下实现了高效的微分。该编程模型允许用户在网格邻域上表达能量项,而系统自动管理并行执行、导数传播、稀疏组装和矩阵无关操作如Hessian-向量乘积。该系统支持标量和向量目标函数、动态交互驱动的稀疏性更新以及与外部GPU稀疏线性求解器的无缝集成。我们在弹性模拟、布料模拟、表面参数化、网格平滑、帧场设计、ARAP变形和球面流形优化等应用中评估了该系统。在这些任务中,该系统在包括PyTorch、JAX、Warp、DrJIT、EnzymeAD和Thallo在内的现有微分框架中表现优异。我们展示了从牛顿法和高斯-牛顿法到L-BFGS和梯度下降等不同求解器类型的加速效果,以及不同导数使用模式,包括Hessian-向量乘积以及完整的稀疏Hessian和雅可比矩阵构造。该系统作为开源代码库在https://github.com/owensgroup/RXMesh上提供。

Comments SIGGRAPH 2026

Journal ref ACM Transactions on Graphics, 45(4), July 2026

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AI中文摘要

我们提出了一种基于GPU的自动微分系统,用于在三角网格上定义的函数,旨在利用网格计算中的局部性和稀疏性。我们的系统通过每个元素的前向模式自动微分来评估导数,将所有计算限制在寄存器和共享内存中,并直接在GPU上组装全局梯度、稀疏雅可比矩阵和稀疏Hessian矩阵。通过避免全局计算图、中间缓冲区和设备-主机同步,我们的方法减少了内存流量,并在静态和动态变化的稀疏性下实现了高效的微分。我们的编程模型允许用户在网格邻域上表达能量项,而我们的系统自动管理并行执行、导数传播、稀疏组装和矩阵无关操作如Hessian-向量乘积。我们的系统支持标量和向量目标函数、动态交互驱动的稀疏性更新以及与外部GPU稀疏线性求解器的无缝集成。我们在弹性模拟、布料模拟、表面参数化、网格平滑、帧场设计、ARAP变形和球面流形优化等应用中评估了我们的系统。在这些任务中,我们的系统在包括PyTorch、JAX、Warp、DrJIT、EnzymeAD和Thallo在内的现有微分框架中表现优异。我们展示了从牛顿法和高斯-牛顿法到L-BFGS和梯度下降等不同求解器类型的加速效果,以及不同导数使用模式,包括Hessian-向量乘积以及完整的稀疏Hessian和雅可比矩阵构造。我们的系统作为开源代码库在https://github.com/owensgroup/RXMesh上提供。

英文摘要

We present a GPU-based system for automatic differentiation (AD) of functions defined on triangle meshes, designed to exploit the locality and sparsity in mesh-based computation. Our system evaluates derivatives using per-element forward-mode AD, confining all computation to registers and shared memory and assembling global gradients, sparse Jacobians, and sparse Hessians directly on the GPU. By avoiding global computation graphs, intermediate buffers, and device-host synchronization, our approach minimizes memory traffic and enables efficient differentiation under both static and dynamically changing sparsity. Our programming model lets users express energy terms over mesh neighborhoods, while our system automatically manages parallel execution, derivative propagation, sparse assembly, and matrix-free operations such as Hessian-vector products. Our system supports both scalar- and vector-valued objectives, dynamic interaction-driven sparsity updates, and seamless integration with external GPU sparse linear solvers. We evaluate our system on applications including elastic and cloth simulation, surface parameterization, mesh smoothing, frame field design, ARAP deformation, and spherical manifold optimization. Across these tasks, our system consistently outperforms state-of-the-art differentiation frameworks, including PyTorch, JAX, Warp, DrJIT, EnzymeAD, and Thallo. We demonstrate speedups across a range of solver types, from Newton and Gauss-Newton for nonlinear least squares to L-BFGS and gradient descent, and across different derivative usage modes, including Hessian-vector products as well as full sparse Hessian and Jacobian construction. Our system is available as open source at https://github.com/owensgroup/RXMesh.

2601.16044 2026-06-05 math.NT

On the Identification of Elliptic Curves That Admit Infinitely Many Twists Satisfying the Birch-Swinnerton-Dyer Conjecture

关于满足Birch-Swinnerton-Dyer猜想的椭圆曲线识别

Barinder S. Banwait, Xiaoyu Huang

AI总结 本文基于Burungale-Skinner-Tian-Wan的研究,提出一个显式算法,应用于LMFDB数据库,识别出所有导数不超过500,000的椭圆曲线,这些曲线有无限多个二次扭曲满足强Birch-Swinnerton-Dyer猜想,并提供了Radziwiłł和Soundararajan猜想的数值证据。

Comments v2, to appear, Algorithmic Number Theory Symposium (ANTS) XVII

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AI中文摘要

Burungale-Skinner-Tian-Wan最近的工作确立了第一个无限家族的二次扭曲非CM椭圆曲线,这些曲线在有理数域上满足强Birch-Swinnerton-Dyer(BSD)猜想。在他们的研究基础上,我们将所需的假设编码到一个显式算法中,并将其应用于L-函数和模形式数据库(LMFDB)中的椭圆曲线数据库,识别出所有导数不超过500,000的椭圆曲线E,这些曲线有无限多个二次扭曲满足强BSD猜想。我们的计算为Radziwiłł和Soundararajan提出的关于Shafarevich-Tate群解析阶的高斯行为的猜想提供了某些数值证据,同时观察到在满足BSD猜想的子家族中存在系统性的正偏置。

英文摘要

Recent work of Burungale-Skinner-Tian-Wan established the first infinite families of quadratic twists of non-CM elliptic curves over $\mathbb{Q}$ for which the strong Birch-Swinnerton-Dyer (BSD) conjecture holds. Building on their results, we encode the required hypotheses into an explicit algorithm and apply it to the database of elliptic curves in the $L$-functions and Modular Forms Database (LMFDB), identifying all elliptic curves $E$ of conductor at most $500{,}000$ that admit infinitely many quadratic twists satisfying the strong BSD conjecture. Our computations provide certain numerical evidence for a conjecture of Radziwiłł and Soundararajan predicting Gaussian behavior in the analytic order of the Shafarevich-Tate group, while also observing a systematic positive bias within the BSD-satisfying subfamily.

2601.22502 2026-06-05 hep-th hep-ph nucl-th

Entanglement in Elastic and Inelastic Two-particle Scatterings at High Energy

高能弹性与非弹性两粒子散射中的纠缠

Robi Peschanski, Shigenori Seki

AI总结 本文研究了高能两粒子散射中横动量产生的纠缠,通过S矩阵框架推导了简化的密度矩阵,推导了弹性与非弹性散射的纠缠熵公式,并通过两体交叉截面表达这些公式。同时,推导了纠缠密度与横动量的关系。应用方面,本文聚焦于正弹性(pn→pn)和非弹性(pn→np)通道散射,比较了相同质子中子含量的两种反应。通过已知的实验数据参数化,评估了弹性与非弹性纠缠熵,发现非弹性散射在pn区域产生更多的整体纠缠。

Comments 25 pages, 6 figures; v2: 26 pages, typos corrected, comments added in Secs. 3.3, 3.4 and C.3

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AI中文摘要

我们研究了高能两粒子散射中横动量产生的纠缠。通过S矩阵框架推导简化的密度矩阵,我们推导了非弹性散射以及弹性散射的纠缠熵公式。我们以两体交叉截面的形式展示了纠缠熵的公式。我们还推导了纠缠密度作为横动量函数的表达式。作为应用,我们聚焦于正弹性(pn→pn)和非弹性(pn→np)通道散射,允许对具有相同质子中子含量的两种反应进行富有成效的比较。我们通过已知的实验数据参数化来评估弹性与非弹性纠缠熵。比较这些纠缠熵,我们发现非弹性散射在pn区域产生比弹性散射更多的整体纠缠。

英文摘要

We study the entanglement produced in transverse momentum by two-particle scattering at high energy. Employing the S-matrix framework for the derivation of reduced density matrices, we formulate the entanglement entropy for an inelastic scattering as well as an elastic one. We display the formulas of the entanglement entropy in terms of two-body cross sections. We also derive the entanglement density as a function of the transverse momentum. As an application, we then focus on both forward elastic ($pn \to pn$) and inelastic ($pn \to np$) channels scattering allowing for a fruitful comparison of the two reactions with the same proton-neutron content. We evaluate the elastic and inelastic entanglement entropy by using known parameterizations of experimental data for neutron-proton reactions. Comparing those entanglement entropies, we observe that the inelastic scattering produces more overall entanglement than the elastic one in the $pn$ sector.

2601.22262 2026-06-05 nucl-ex

Direct Measurement of the $^{59}$Cu$(p,α)^{56}$Ni Excitation Function to Constrain the Ni--Cu Cycle Strength and Its Impact on Explosive Nucleosynthesis

直接测量59Cu(p,α)56Ni激发函数以约束镍-铜循环强度及其对爆炸性核合成的影响

E. Lopez-Saavedra, M. L. Avila, W. -J. Ong, P. Mohr, A. Psaltis, S. Ahn, H. Arora, L. Balliet, K. Bhatt, S. M. Cha, K. A. Chipps, J. Dopfer, I. A. Tolstukhin, R. Jain, M. J. Kim, K. Kolos, F. Montes, D. Neto, S. D. Pain, J. Pereira, J. S. Randhawa, L. J. Sun, C. Ugalde, L. Wagner

AI总结 通过逆康恩学方法在FRIB的高效率MUSIC主动靶探测器上直接测量了59Cu(p,α)56Ni激发函数,从而约束不同爆炸恒星物理场景中镍-铜循环的强度,并对其在X射线爆发和中微子驱动风中的nu-p过程效率产生影响。

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AI中文摘要

在质心系中,利用FRIB的高效率MUSIC主动靶探测器,通过逆康恩学方法,在2.43-5.88 MeV范围内对59Cu(p,a)56Ni激发函数进行了新的直接测量。该反应在约束不同类型爆炸恒星物理场景(如I型X射线爆发和超新星核心坍缩后中微子驱动风中的nu-p过程)的镍-铜循环强度方面起着关键作用。新确定的恒星速率系统性地低于之前的估计,使得X射线爆发中的镍-铜循环回收率降至低于3%,并增强了整个相关温度范围内的nu-p过程效率,可能使其有效操作温度扩展至T9=3.94(+0.99/-0.85).

英文摘要

A new direct measurement of the 59Cu(p,a)56Ni excitation function from 2.43-5.88 MeV in the center-of-mass was performed in inverse kinematics using the high-efficiency MUSIC active-target detector at FRIB. This reaction plays a critical role in constraining the strength of the NiCu cycle in different explosive astrophysical scenarios such as Type I X-ray bursts and the nu-p process in neutrino-driven winds after a core-collapse supernova. The newly derived stellar rate is systematically lower than previous estimates, suppressing NiCu cycle recycling in X-ray bursts to below 3% and enhancing nu-p process efficiency throughout the relevant temperature range, potentially extending its effective operation to temperatures as high as T9 = 3.94 (+0.99/-0.85).

2601.13249 2026-06-05 math.AG math.CO

Volume polynomials

体积多项式

June Huh

AI总结 本文研究了体积多项式这一类具有显著分析和组合性质的对数凹多项式,探讨了其实现问题、基本不等式以及在代数Matroid组合学中的应用。

Comments 24 pages, minor revision. Footnote 1 on Conjecture 1.6 is new

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AI中文摘要

体积多项式构成了一个 distinguished 的 log-concave 多项式类,具有显著的分析和组合性质。我将回顾与它们相关的实现问题,回顾它们所满足的基本不等式,并讨论它们在代数Matroid组合学中的应用。这些笔记基于在科罗拉多州立大学2025年代数几何夏季研究学院所做的讲座。

英文摘要

Volume polynomials form a distinguished class of log-concave polynomials with remarkable analytic and combinatorial properties. I will survey realization problems related to them, review fundamental inequalities they satisfy, and discuss applications to the combinatorics of algebraic matroids. These notes are based on lectures given at the 2025 Summer Research Institute in Algebraic Geometry at Colorado State University.

2601.21954 2026-06-05 math.RT

Asymptotic Expansion for Expanding Spherical Averages in Real Rank One

实秩为一李群上扩张扇形平均的渐近展开

Zhiyuan Deng, Yutian Sun

AI总结 本文研究了实秩为一李群在紧致商上的扩张扇形平均的渐近展开问题,以SO(n,1)为模型案例,利用调和分析和表示论工具,通过Casimir算子的作用将问题转化为一个描述沿扩张A方向演变的常微分方程(ODE),进而推导出渐近展开。

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AI中文摘要

本文建立了实秩为一李群在紧致商上的扩张扇形平均的渐近展开。利用调和分析和表示论的工具,通过Casimir算子的作用,将问题转化为一个描述沿扩张A方向演变的常微分方程(ODE)。然后通过分析这个ODE推导出渐近展开。

英文摘要

This paper establishes an asymptotic expansion for expanding sector average on compact quotients of real rank-one Lie groups, with $SO(n,1)$ as a model case. Using tools from harmonic analysis and representation theory, the problem is reduced, via the action of the Casimir operator, to an ordinary differential equation(ODE) governing the evolution along the expanding $A$-direction. The asymptotic expansion is then derived from the analysis of this ODE.

2601.21240 2026-06-05 quant-ph gr-qc

Reflecting boundary induced modulation of tripartite coherence harvesting

反射边界诱导的三元相干提取

Shu-Min Wu, Xiao-Ying Jiang, Xiang-Yue Yu, Zhihong Liu, Xiao-Li Huang

AI总结 本文研究了在无限完美反射边界附近,三个静态Unruh-DeWitt探测器与无质量标量真空场局部相互作用时,量子相干的提取过程。结果显示,探测器与边界距离的减小会导致量子相干的单调退化,而相同边界效应可以同时保持甚至增强提取的量子纠缠。此外,当探测器具有不同的能量间隙时,相干提取进一步受到抑制;然而,这种非相同配置显著提高了纠缠提取的效率,并大幅扩展了能够生成非可忽略纠缠的探测器分离范围。尽管非本地量子相干的提取在更广的探测器分离范围内可行,但正交探测器配置在相干提取中优于平行配置,突显了探测器几何形状的定量影响。

Comments 20 pages, 7 figures

Journal ref JHEP 05 (2026) 123

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AI中文摘要

我们研究了三个静态Unruh-DeWitt(UDW)探测器在无限完美反射边界附近与无质量标量真空场局部相互作用时量子相干的提取。根据设置,探测器被放置在平行或垂直于边界的位置,其能量间隙被选择以满足层次$Ω_C≥Ω_B≥Ω_A$。我们的分析表明,减少探测器与边界之间的距离会导致量子相干的单调退化,而相同边界效应可以同时保持并甚至增强提取的量子纠缠。此外,当探测器具有不同的能量间隙时,相干提取进一步受到抑制;值得注意的是,这种非相同配置显著提高了纠缠提取的效率,并明显扩展了能够生成非可忽略纠缠的探测器分离范围。然而,非本地量子相干的提取在更广的探测器分离范围内是可行的。尽管表现出相似的整体行为,正交探测器配置在相干提取中优于平行配置,突显了探测器几何形状的定量影响。总体而言,我们的研究揭示了在结构化真空场中,量子相干和纠缠作为操作资源之间的层次差异:量子相干不仅在空间上更容易获取,而且比纠缠更稳健,而纠缠表现出更丰富的特征,并可通过边界效应和探测器非均匀性进行选择性激活和增强。

英文摘要

We study the extraction of quantum coherence by three static Unruh-DeWitt (UDW) detectors that interact locally with a massless scalar vacuum field in the vicinity of an infinite perfectly reflecting boundary. Depending on the setup, the detectors are positioned either parallel or orthogonal to the boundary, with their energy gaps chosen to satisfy the hierarchy $Ω_C\geq Ω_B\geq Ω_A$. Our analysis reveals that decreasing the detector-boundary separation leads to a monotonic degradation of quantum coherence, whereas the same boundary effect can simultaneously preserve and even amplify the harvested quantum entanglement. Moreover, when the detectors possess distinct energy gaps, coherence extraction is further inhibited; strikingly, such non-identical configurations substantially enhance the efficiency of entanglement harvesting and markedly extend the range of detector separations over which non-negligible entanglement can be generated. Nevertheless, the harvesting of nonlocal quantum coherence is achievable over a significantly broader range of detector separations than that of quantum entanglement. Despite exhibiting similar overall behavior, orthogonal detector configurations outperform parallel ones in coherence harvesting, highlighting the quantitative influence of detector geometry. Overall, our study reveals a hierarchical distinction between quantum coherence and entanglement as operational resources in structured vacuum fields: quantum coherence is not only more readily accessible across space but also more robust than entanglement, whereas entanglement exhibits richer features and can be selectively activated and enhanced through boundary effects and detector non-uniformity.

2507.23039 2026-06-05 math.CO

Character theoretic techniques for nonabelian partial difference sets

非交换部分差集的特征论技术

Seth R. Nelson, Eric Swartz

AI总结 本文研究非交换群中部分差集(PDS)的特征论方法,证明了Ott关于广义四边形的特征论结果的类比,并利用这些技术计算了可能的PDS与父群共轭类的交集,证明了PDS的不存在性,并构造了多个非交换群中的PDS实例。

Comments Table entries in Appendix C updated and corrected

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AI中文摘要

一个$(v,k,λ, μ)$-部分差集(PDS)是群$G$中大小为$k$的子集$D$,使得每个非单位元$g$可以以$λ$或$μ$种不同的方式表示为乘积$xy^{-1}$,$x,y \in D$,取决于$g$是否在$D$中。如果$D$是逆闭的且$1 otin D$,则Cayley图${ m Cay}(G,D)$是一个$(v,k,λ, μ)$-强正则图(SRG)。近年来,研究PDS在非交换群中的兴趣增加,本文旨在开发适用于非交换环境的特征论技术。我们证明了Ott关于广义四边形的特征论结果的类比在一般PDS设定中也成立,并能利用这些技术计算父群共轭类与可能PDS的交集。通过这些技术,我们能够证明PDS在许多实例中不存在,并在PDS可能仍存在的案例中提供严格限制。此外,我们还能利用这些技术构造多个非交换群中的PDS实例,包括与Clapham研究的块正则Steiner三元组系统相关的无限族真正非交换PDS,以及与Wilson首先研究的块正则Steiner 2-设计相关的无限族真正非交换PDS。

英文摘要

A $(v,k,λ, μ)$-partial difference set (PDS) is a subset $D$ of size $k$ of a group $G$ of order $v$ such that every nonidentity element $g$ of $G$ can be expressed in either $λ$ or $μ$ different ways as a product $xy^{-1}$, $x, y \in D$, depending on whether or not $g$ is in $D$. If $D$ is inverse closed and $1 \notin D$, then the Cayley graph ${\rm Cay}(G,D)$ is a $(v,k,λ, μ)$-strongly regular graph (SRG). PDSs have been studied extensively over the years, especially in abelian groups, where techniques from character theory have proven to be particularly effective. Recently, there has been considerable interest in studying PDSs in nonabelian groups, and the purpose of this paper is develop character theoretic techniques that apply in the nonabelian setting. We prove that analogues of character theoretic results of Ott about generalized quadrangles of order $s$ also hold in the general PDS setting, and we are able to use these techniques to compute the intersection of a putative PDS with the conjugacy classes of the parent group in many instances. With these techniques, we are able to prove the nonexistence of PDSs in numerous instances and provide severe restrictions in cases when such PDSs may still exist. Furthermore, we are able to use these techniques constructively, computing several examples of PDSs in nonabelian groups not previously recognized in the literature, including an infinite family of genuinely nonabelian PDSs associated to the block-regular Steiner triple systems originally studied by Clapham and related infinite families of genuinely nonabelian PDSs associated to the block-regular Steiner $2$-designs first studied by Wilson.

2601.19579 2026-06-05 physics.acc-ph nucl-ex physics.ins-det

First observation of the $γ$-ray beam production by the backward Compton scattering of reflected synchrotron radiation in the extreme ultraviolet range

极端紫外范围内反射同步辐射光的反向康普顿散射首次观测到γ射线束的产生

Norihito Muramatsu, Manabu Miyabe, Masahiro Okabe, Schin Date, Tetsuo Harada, Kazuhiro Kanda, Shuji Miyamoto, Haruo Ohkuma, Hajime Shimizu, Shinsuke Suzuki, Atsushi Tokiyasu

AI总结 该研究通过反向康普顿散射利用反射的同步辐射光在极端紫外范围内首次观测到γ射线束的产生,展示了新的高能γ射线束源的开发方法。

Comments 18 pages, 8 figures

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AI中文摘要

光子与高能电子的康普顿散射是一种基本的量子力学过程,广泛用于产生γ射线束以进行科学研究。与传统方式将激光注入存储环不同,我们开发了一种创新方法,通过极端紫外(EUV)光的反向康普顿散射获得接近环能级的极高能量。在此方法中,从存储环回旋加速器中获得的92 eV光子被Mo/Si多层镜反射回原环。因此,在1 GeV环NewSUBARU上进行的演示实验中首次观测到利用EUV光康普顿散射产生γ射线束。测量的能量谱被理论计算良好再现,最大能量为0.543 GeV。生产率在0.160 GeV以上的能量为1.4 ± 0.1 kcps。该速率通过亮度和散射截面定量解释。本工作为未来应用如强子光产生实验的新γ射线束源的创建铺平了道路。

英文摘要

Compton scattering of photons off high-energy electrons is a fundamental quantum mechanical process widely utilized to produce a $γ$-ray beam for scientific research. Instead of injecting laser light into a storage ring as a conventional way, we have developed an innovative method to achieve drastically higher energies approaching the ring energy by the backward Compton scattering of extreme ultraviolet (EUV) light. In this method, $92$ $\mathrm{eV}$ photons obtained from an undulator in a storage ring were reflected back to the original ring using a Mo/Si multilayer mirror. Consequently, $γ$-ray beam production through the EUV light Compton scattering using reflected synchrotron radiation was observed for the first time in a demonstration experiment conducted at the $1$ $\mathrm{GeV}$ ring, NewSUBARU. The measured energy spectrum was well reproduced by a theoretical calculation with the maximum energy of $0.543$ $\mathrm{GeV}$. The production rate was $1.4 \pm 0.1$ kcps for the energies above $0.160$ $\mathrm{GeV}$. This rate was quantitatively explained by the luminosity and the scattering cross section. The present work paved the way to create a new $γ$-ray beam source for future applications such as hadron photoproduction experiments.

2601.18941 2026-06-05 quant-ph

Krylov's State Complexity and Information Geometry in Qubit Dynamics

Krylov的状态复杂性与信息几何在量子比特动力学中的应用

Carlo Cafaro, Emma Clements, Vishnu Vardhan Anuboyina

AI总结 本文比较了Krylov的状态复杂性与信息几何测度在两个能级系统量子演化的复杂性,分析了量子比特在Bloch球上的动力学,探讨了静止和非静止哈密顿量生成的轨迹,并展示了两种测度在量子动力学中反映的不同方面。

Comments 36 pages, 8 figures

Journal ref Eur. Phys. J. Plus 141, 639 (2026)

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AI中文摘要

我们比较了Krylov的状态复杂性与信息几何(IG)测度在两个能级系统量子演化的复杂性。聚焦于量子比特在Bloch球上的动力学,我们分析了由静止和非静止哈密顿量生成的动力学,对应于测地线和非测地线轨迹。我们以几何方式提出了Krylov复杂性,即时和时间平均意义上,并将其与以效率和曲率特征化的信息几何复杂性进行对比。我们证明了这两种测度反映了量子动力学根本不同的方面:Krylov的状态复杂性量化了演化状态相对于初始状态的方向扩展,而信息几何复杂性捕捉了轨迹上在Bloch球上有效探索的体积。这种几何区别解释了它们不等价的行为,并突显了基于状态和信息几何的复杂性概念在量子系统中的互补性。

英文摘要

We compare Krylov's state complexity with an information-geometric (IG) measure of complexity for the quantum evolution of two-level systems. Focusing on qubit dynamics on the Bloch sphere, we analyze evolutions generated by stationary and nonstationary Hamiltonians, corresponding to geodesic and nongeodesic trajectories. We formulate Krylov complexity in geometric terms, both instantaneously and in a time-averaged sense, and contrast it with an IG complexity of quantum evolutions characterized in terms of efficiency and curvature. We show that the two measures reflect fundamentally different aspects of quantum dynamics: Krylov's state complexity quantifies the directional spread of the evolving state relative to the initial state, whereas the IG complexity captures the effective volume explored along the trajectory on the Bloch sphere. This geometric distinction explains their inequivalent behavior and highlights the complementary nature of state-based and information-geometric notions of complexity in quantum systems.

2601.18674 2026-06-05 physics.flu-dyn physics.ao-ph physics.geo-ph

Meltwater transport and mixing layer growth near the ice--ocean interface

冰水输送与冰-海洋界面混合层增长

Sofía Allende, Louis-Alexandre Couston, Simon Thalabard, Benjamin Favier

AI总结 研究冰融化进入盐水在极地海洋冰-海洋界面的动力学作用,通过高分辨率数值模拟分析湍流对混合层增长的影响,发现混合层超扩散增长而界面边界层扩散增长,揭示了双扩散效应的局限性。

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AI中文摘要

冰融化进入盐水在极地海洋冰-海洋界面的动力学中起根本作用。冰融化涉及界面热力学、水体中流体输运以及环境海洋性质的复杂相互作用。关键控制参数是密度比$R_ρ$,与环境海洋盐度成正比,以及Lewis数$Le = κ_T/κ_S$,比较热和盐扩散系数。增加盐度已知会减缓融化,随着$R_ρ$增加,融化速率从亚扩散到扩散。本文评估了湍流在这一转变中的作用,使用高分辨率数值模拟二维Boussinesq方程,具有缓慢融化的上边界。分析温度和融水混合层的非稳态增长,变化Lewis数和密度比。尽管融水持续被对流输送到水体中,但发现接近界面处从对流到扩散的转变。这一转变反映为界面边界层的形成,调节融水流入湍流水体的流量。对于$R_ρ\gtrsim 10$,使用基于融水浓度阈值的混合层诊断,观察到湍流层超扩散增长$\propto t^{1.33}$,而界面边界层扩散增长$\propto t^{0.5}$但具有非普遍的预因子。这些结果表明双扩散效应在此被限制在界面,突显了基于固定浓度阈值的诊断在海洋学应用中的潜在局限性。

英文摘要

Ice melting into saline water plays a fundamental role in the dynamics near the ice-ocean interface in polar oceans. The physics of ice melting involves a non-trivial interplay between thermodynamics at the interface, hydrodynamic transport in the bulk and the properties of the ambient ocean. The key control parameters are the density ratio $R_ρ$ proportional to the ambient ocean salinity and the Lewis number $Le = κ_T/κ_S$, which compares the thermal and salt diffusivities. Increasing the salinity is known to slow down melting, with the melt rate transitioning from subdiffusive to diffusive as $R_ρ$ increases. Here, we ssess the role of turbulence in this transition, using highly-resolved numerical simulations of the two-dimensional Boussinesq equations with a slowly melting upper boundary. We analyse the non-stationary growth of the temperature and meltwater mixing layers, varying the Lewis number and the density ratio. While meltwater is continuously entrained by convection inside the bulk, we identify a transition from convection to diffusion close to the interface. This transition is reflected by the formation of an interfacial boundary layer that regulates the flux of meltwater pouring into the turbulent bulk for $R_ρ\gtrsim 10$. Using mixing-layer diagnostics based on meltwater-concentration thresholds, we observe that the turbulent layer grows super-diffusively $\propto t^{1.33}$, while the interfacial boundary layer expands diffusively $\propto t^{0.5}$ but with a non-universal prefactor. These results indicate that double-diffusive effects are here confined to the interface, and highlight potential limitations of diagnostics based on fixed concentration thresholds in oceanographic applications.

2510.23243 2026-06-05 math.AP

Classification results for bounded positive solutions to the critical $p$-Laplace equation

临界p-拉普拉斯方程有界正解的分类结果

Giulio Ciraolo, Michele Gatti

AI总结 本文通过提供最优或接近最优的积分估计,证明了临界p-拉普拉斯方程在R^n中(n≥3)的每一个正、有界或适度增长的局部弱解,若其在球上的下确界行为适当,则必须是气泡解。

Comments Comments are welcome

Journal ref Nonlinear Anal. 272 (2026), Paper No. 114190

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AI中文摘要

通过提供最优或接近最优的积分估计,我们证明了在R^n(n≥3)中,每一个正、有界或适度增长的局部弱解,其在球上的下确界行为适当的情况下,必须是气泡解。

英文摘要

By providing optimal or nearly optimal integral estimates, we show that every positive, bounded or moderately growing, local weak solution to the critical $p$-Laplace equation in $\mathbb{R}^n$, with $n\geq 3$, and whose infimum over a ball behaves properly must be a bubble.

2601.16305 2026-06-05 gr-qc hep-th

Light propagation and quasinormal modes of a topologically charged Schwarzschild-Klinkhamer wormhole

拓扑荷 Schwarzschild-Klinkhamer 虫洞的光传播与拟正则模

C. F. S. Pereira, H. Belich, A. R. Soares, Marcos V. de S. Silva, R. L. L. Vitória, A. A. Araújo Filho

AI总结 本文理论分析了由几何缺陷产生的虫洞中的零测地线、临界光子轨道和阴影形成,通过弱场和强场下的偏转角研究光传播,并计算了标量扰动的拟正则模和时域解。

Comments 49 pages, 13 figures and 6 tables -- version accepted for publication in PDU

Journal ref Physics of the Dark Universe 53 (2026) 102365

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AI中文摘要

在这项工作中,我们提出了对由几何缺陷产生的虫洞相关的零测地线、临界光子轨道和阴影形成的理论分析。通过弱场和强场下的偏转角研究了光在该时空中的传播。推导了每个区域的解析展开式,并用于表征引力透镜可观测量。通过改变整体单极子电荷,我们评估了其对可观测量的影响,并确定了可能被当前或未来观测探测器访问的参数范围。最后,我们还计算了标量扰动的拟正则模以及时域解。

英文摘要

In this work, we present a theoretical analysis of null geodesics, critical photon orbits, and shadow formation associated with a wormhole generated by a geometric defect. The propagation of light in this spacetime is examined through the deflection angle in both weak- and strong-field regimes. Analytical expansions are derived in each regime and employed to characterize gravitational lensing observables. By varying the global monopole charge, we evaluate its impact on these observables and determine parameter ranges that may be accessible to current or future observational probes. Finally, we calculate the quasinormal modes as well as the time-domain solution for scalar perturbations as well.

2504.20556 2026-06-05 cs.CR

Mutual Information Minimization for Side-Channel Attack Resistance via Optimal Noise Injection

通过最优噪声注入实现侧信道攻击防护的互信息最小化

Jiheon Woo, Donggyun Ryu, Daewon Seo, Young-Sik Kim, Namyoon Lee, Yuval Cassuto, Yongjune Kim

AI总结 本文通过将侧信道攻击建模为通信信道,利用互信息最小化技术在功率约束下优化噪声注入,以减少信息泄露,提升系统安全性。

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AI中文摘要

侧信道攻击(SCAs)通过物理泄露如功耗、时序变化和电磁辐射提取密钥,对系统安全构成严重威胁。现有防护措施中,人工噪声注入被认为是效果最显著的技巧。然而,其高能耗对资源受限系统如物联网设备构成挑战,推动了更高效保护方案的发展。本文将SCAs建模为通信信道,旨在通过最小化秘密信息与侧信道观测间的互信息来抑制信息泄露,受功率约束。我们首先考虑高斯输入情况,其中互信息成为信道容量,是衡量信息泄露的一种方式。然后通过识别优化保持凸性的条件,并利用基本I-MMSE关系推导最优噪声分配。数值结果表明,所提方法相比传统技术显著减少了互信息,证明了其在紧约束功率下的安全关键系统中的有效性。

英文摘要

Side-channel attacks (SCAs) pose a serious threat to system security by extracting secret keys through physical leakages such as power consumption, timing variations, and electromagnetic emissions. Among existing countermeasures, artificial noise injection is recognized as one of the most effective techniques. However, its high power consumption poses a major challenge for resource-constrained systems such as Internet of Things (IoT) devices, motivating the development of more efficient protection schemes. In this paper, we model SCAs as a communication channel and aim to suppress information leakage by minimizing the mutual information between the secret information and side-channel observations, subject to a power constraint on the artificial noise. We first consider the Gaussian input case, where the mutual information becomes the channel capacity, which is one way to quantify the information leakage. We then extend the framework to arbitrary input distributions by identifying conditions under which the optimization remains convex and by leveraging the fundamental I-MMSE relationship to derive the optimal noise allocation. Numerical results show that the proposed methods substantially reduce mutual information compared with conventional techniques, demonstrating their effectiveness for security-critical systems operating under tight power constraints.

2601.15693 2026-06-05 quant-ph

Fractional squeezing: spectra and dynamics from generalized squeezing Hamiltonian with fractional orders

分数压缩:从广义压缩哈密顿量的分数阶中获得频谱和动力学

Sahel Ashhab

AI总结 本文研究了广义压缩哈密顿量的分数阶压缩问题,确定了临界点的位置并预测了这些点的行为,揭示了频谱从连续到离散转变以及振荡幅度从无限到有限转变的特征。

Comments 15 pages (preprint); 5 figures

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AI中文摘要

我们将广义压缩问题推广到包含分数阶压缩阶数n的值。这种方法使我们能够确定临界点的位置,这些点是行为质变发生的地方,并且能够准确预测这些临界点的行为,这在传统计算方法中具有挑战性。基于我们的数值计算,我们以高度置信度识别出频谱从连续到离散转变的点以及振荡从具有渐近无限幅度到有限幅度转变的点。此外,我们还数值研究了大n区域的行为,并提供了一个与数值结果一致的直观解释。

英文摘要

We generalize the generalized-squeezing problem to include fractional values of the squeezing order $n$. This approach allows us to determine the locations of critical points at which qualitative changes in behaviour occur and accurately predict the behaviour at these critical points, which are challenging for conventional computational methods. Based on our numerical calculations, we identify with a high degree of confidence the point at which the spectrum turns from continuous to discrete and the point at which oscillations turn from having asymptotically infinite amplitudes to finite amplitudes. Furthermore, we numerically investigate the behaviour in the large $n$ regime and provide an intuitive explanation that coincides with the numerical results.