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2606.03306 2026-06-11 math.CV 版本更新

Area Theorems and Quasiconformal Extensions of Harmonic Mappings with a Pole

带极点的调和映射的面积定理与拟共形延拓

Zhijun Chen, Limei Wang

AI总结 本文针对单位圆盘中具有单极点且允许对数奇异性的单叶调和映射,建立了广义面积定理,并给出了显式k-拟共形延拓的充分条件。

Comments 12 pages

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AI中文摘要

本文研究类 \Sigma_{H}^{k}(p),即单位圆盘 \mathbb{D} 中在 p\in[0,1) 处具有单极点、保持定向的单叶调和映射,且对 k\in[0,1) 允许到扩充复平面的 k-拟共形延拓。2024 年,Bhowmik 和 Satpati 建立了一个面积定理,并导出了属于 \Sigma_{H}^{k}(p) 且不含对数项的调和映射的 k-拟共形延拓的充分条件。受其工作启发,我们研究了存在对数奇点时的相应问题。我们的主要贡献有两方面:首先,我们证明了 \Sigma_{H}^{k}(p) 中所有映射的广义面积定理;其次,我们得到了 \mathbb{D} 中保持定向的单叶调和映射允许显式 k-拟共形延拓的一个充分条件。这些结果将前述工作推广到允许对数奇点的情形。

英文摘要

In this paper, we study the class Σ_{H}^{k}(p) of sense-preserving univalent harmonic mappings in the unit disk \mathbb{D} that possess a simple pole at p\in[0,1) and admit a k-quasiconformal extension to the extended complex plane for k\in[0,1). In 2024, Bhowmik and Satpati established an area theorem and derived a sufficient condition for the k-quasiconformal extension of harmonic mappings belonging to Σ_{H}^{k}(p) without logarithmic terms. Motivated by their work, we investigate the corresponding problem when a logarithmic singularity is present. Our main contributions are two-fold: we first prove a generalized area theorem for all mappings in Σ_{H}^{k}(p); we then obtain a sufficient condition for sense-preserving univalent harmonic mappings in \mathbb{D} to admit explicit k-quasiconformal extensions. These results extend the aforementioned work to the setting where logarithmic singularities are allowed.

2606.03185 2026-06-11 math.AP 版本更新

Fractional Sobolev embeddings on noncommutative torus

非交换环面上的分数阶Sobolev嵌入

F. Sukochev, R. Tastankul, K. Tulenov, D. Zanin

AI总结 研究非交换环面上的非交换分数阶对称Sobolev空间,通过证明非交换分布分数阶Sobolev不等式和O'Neil不等式的非交换版本,得到Sobolev嵌入、Cwikel-Solomyak型估计以及扩散方程Cauchy问题温和解的L2时间衰减。

Comments 30 pages. One reference is added. Welcome to any comments!

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AI中文摘要

本文研究了非交换环面上的非交换分数阶对称Sobolev空间。我们证明了非交换分布分数阶Sobolev不等式,并作为其应用,得到了Sobolev嵌入。为了获得这些结果,我们首先证明了卷积的著名O'Neil不等式的非交换版本。作为我们主要结果的第一个应用,我们得到了Cwikel-Solomyak型估计。作为另一个应用,我们展示了在这个非交换设定下扩散方程Cauchy问题的温和解的$L_2$时间衰减。当$ heta=0$时,我们的结果恢复了环面上Sobolev嵌入的许多已知结果。

英文摘要

In this paper, we study the noncommutative fractional symmetric Sobolev spaces on noncommutative torus. We prove noncommutative distributional fractional Sobolev inequality and as its application, we obtain Sobolev embeddings. In order to obtain these results, we first prove a noncommutative version of the famous O'Neil inequality for the convolution. As a first application of our main results, we obtain a Cwikel-Solomyak-type estimate. As an another application, we show a $L_2$-time decay for the mild solution of the Cauchy problem for the diffusion equation in this noncommutative setting. When $θ=0,$ our results recover many known results on Sobolev embedding on the torus.

2606.02972 2026-06-11 math.CO math.RT 版本更新

Uncrowding the 5-Vertex Model: RSK and Crystal Structures

5-顶点模型的解拥挤:RSK与晶体结构

Lisa Johnston, Evuilynn Nguyen, Anne Schilling

AI总结 本文通过在Motegi-Sakai的5-顶点模型上直接定义Robinson-Schensted-Knuth对应和解拥挤操作,构建了该模型状态的晶体结构,从而综合了组合与晶格理论方法。

Comments 28 pages, 9 figures; v2: added reference, fixed typos and notation

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AI中文摘要

虽然集合值杨表的解拥挤算法长期以来在证明稳定对称Grothendieck多项式的Schur正性中起着重要作用,但晶格模型已成为研究对称函数(特别是对称Grothendieck多项式)的现代框架。在这项工作中,我们通过在Motegi和Sakai的5-顶点模型及其后来由Buciumas、Scrimshaw和Weber重新解释的模型上直接定义Robinson-Schensted-Knuth(RSK)对应和解拥挤操作,综合了这些组合和晶格理论方法。我们基于晶格的RSK公式产生了一个强有力的新结果:直接构建了5-顶点模型状态上的相关晶体结构。

英文摘要

While the uncrowding algorithm on set-valued tableaux has long been instrumental in proving the Schur positivity of stable symmetric Grothendieck polynomials, lattice models have emerged as a modern framework for investigating symmetric functions, in particular symmetric Grothendieck polynomials. In this work, we synthesize these combinatorial and lattice-theoretic approaches by defining both the Robinson--Schensted--Knuth (RSK) correspondence and the uncrowding operation directly on a 5-vertex model of Motegi and Sakai and its subsequent reinterpretation by Buciumas, Scrimshaw, and Weber. Our lattice-based RSK formulation yields a powerful new result: the direct construction of the associated crystal structure on the states of the 5-vertex model.

2606.02847 2026-06-11 math.CA math.FA math.PR 版本更新

Sharp log-Sobolev inequalities on finite cyclic groups

带词长的有限循环群的尖锐对数Sobolev不等式

Xinyuan Xie, Haonan Zhang

AI总结 本文证明了对于均匀概率测度下的循环群Z_n,带词长ψ_n(k)=min(k,n-k)的拉普拉斯算子满足尖锐对数Sobolev不等式,常数2π与n无关(n≥4)。

Comments 10 pages. Presentation revised. Circle case added

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AI中文摘要

设$\mathbb Z_n$为配备均匀概率测度$\pi$的循环群,$-A_{\psi_n}$为关于词长$\psi_n(k) = \min(k,n-k)$的拉普拉斯算子。我们证明了尖锐的对数Sobolev不等式$$ \operatorname{Ent}_{\pi}(f^2) \le 2\pi\bigl(f A_{\psi_n} f\bigr), \qquad f:\mathbb Z_n \to \mathbb C, $$ 对所有$n \ge 4$成立。证明受Frank和Ivanisvili~\cite{FrankIvanisvili2026}关于最近邻简单随机游走的尖锐对数Sobolev不等式工作的启发。我们使用他们的三次主项约化思想,但将他们的高频估计替换为适应词长乘子的傅里叶块估计。同样的结果最近也被Yao~\cite{Yao2026}使用完全不同的方法得到。

英文摘要

Let $\mathbb Z_n$ be the cyclic group equipped with the uniform probability measure $π$, and let $A_{ψ_n}$ be the Laplacian with word length \[ ψ_n(k) = \min(k,n-k). \] We prove the sharp log-Sobolev inequality \[ \text{Ent}_π(f^2) \le 2π(f A_{ψ_n} f), \qquad f:\mathbb Z_n \to [0,\infty), \] for every $n \ge 4$. The proof is inspired by the recent work of Frank and Ivanisvili~\cite{FrankIvanisvili2026} on a sharp log-Sobolev inequality for nearest-neighbor simple random walk. We use their cubic-majorant reduction, which turns the problem into a 3rd moment estimate; the new point is a blockwise 3rd moment estimate adapted to the word-length multiplier. The same 3rd moment argument also recovers the log-Sobolev inequality for Poisson-semigroup on the circle, first proved by Weissler~\cite{Weissler1980}. The same sharp inequalities were also obtained recently by Yao~\cite{Yao2026} by a different method.

2606.02779 2026-06-11 math.AT 版本更新

Burklund-Lin-Wang-Xu Methods in the Cofiber-of-Tau Formalism and Applications to Equivariant Slice Differentials

Burklund-Lin-Wang-Xu 方法在 Tau 余纤维形式体系中的应用及对等变片微分的应用

Yuchen Wu

AI总结 通过 Burklund-Isaksen-Pstragowski-Wang-Xu 的 tau 余纤维形式体系重新研究谱序列理论,定义了过滤谱间映射的隐藏扩张,将广义 Leibniz 规则和 Mahowald 技巧推广到更广泛设置,并应用于 C4-等变片谱序列得到新的“异种转移”微分。

Comments 136 pages, 8 figures, minor corrections and clarifications, comments are welcome

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AI中文摘要

我们通过 Burklund-Isaksen-Pstragowski-Wang-Xu 的 $\tau$ 余纤维形式体系重新研究了谱序列理论,研究了过滤谱的 $(\infty,1)$-范畴。在此框架下,我们定义并分析了沿过滤谱的任意映射的隐藏扩张,建立了计算原理,将 Lin-Wang-Xu 的广义 Leibniz 规则和广义 Mahowald 技巧,以及 Burklund 的全微分 Leibniz 规则,从 Adams 谱序列推广到这一更广泛的设置。我们的表述使用了更精细的分层扩张概念,这略微强化了这些陈述,即使对于 Adams 谱序列也是如此。作为应用,我们研究了等变片谱序列,并获得了 Hill-Hopkins-Ravenel 理论 $\mathrm{BP}^{((C_4))}\langle m\rangle$(对于每个 $m \ge 1$)的 $C_4$-片谱序列中新的“异种转移”微分族。

英文摘要

We reinvestigate the theory of spectral sequences by studying the $(\infty,1)$-category of filtered spectra through the cofiber-of-$τ$ formalism of Burklund-Isaksen-Pstragowski-Wang-Xu. In this framework, we define and analyze hidden extensions along arbitrary maps of filtered spectra, establishing computational principles that extend the generalized Leibniz rule and the generalized Mahowald trick of Lin-Wang-Xu, as well as Burklund's Leibniz rule for total differentials, from the Adams spectral sequence to this broader setup. Our formulation uses a more refined, layered notion of extension, which slightly sharpens these statements even for the Adams spectral sequence. As an application, we study equivariant slice spectral sequences and obtain new families of "exotic transfer" differentials in the $C_4$-slice spectral sequences for the Hill-Hopkins-Ravenel theories $\mathrm{BP}^{((C_4))}\langle m\rangle$ for every $m \ge 1$.

2606.02419 2026-06-11 physics.chem-ph cond-mat.mtrl-sci physics.comp-ph 版本更新

DPA4: Pushing the Accuracy-Cost Frontier of Interatomic Potentials with EMFA SO(2) Convolution

DPA4: 利用EMFA SO(2)卷积推动原子间势的精度-成本前沿

Tiancheng Li, Wentao Li, Anyang Peng, Jianming Xue, Linfeng Zhang, Duo Zhang, Han Wang

AI总结 本文提出DPA4架构,通过EMFA SO(2)等变卷积和编译器友好的训练路径,在降低参数和训练成本的同时,在Matbench Discovery等基准上达到最优精度-成本平衡。

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AI中文摘要

机器学习原子间势现在在标准基准上接近量子力学精度,但最具表现力的等变架构的训练成本已成为严重瓶颈。我们引入了DPA4,一种SE(3)-等变原子间势架构,具有EMFA(边缘条件、多焦点、注意力)SO(2)-等变卷积,该卷积结合了低秩边缘-节点SO(2)-等变乘积、用于消息非线性的多焦点设计以及用于消息聚合的包络门控注意力。Lebedev网格投影进一步将非线性中的SO(3)-等变性保持到机器精度。编译器友好的保守能量梯度训练路径在torch.compile下提供了高达约3倍的挂钟加速。在合规的Matbench Discovery基准上,DPA4-Pro在排行榜上获得了最佳综合性能得分(CPS),而276万参数的DPA4-Air以10.9倍更少的参数和42.9倍更少的训练计算量,超过了3010万参数的eSEN-30M-MP基线的精度。在SPICE-MACE-OFF上,540万参数的DPA4-Plus将650万参数的eSEN基线的总分子能量和力误差分别降低了29%和30%,而270万参数的DPA4-Air仍然以约2.4倍更少的参数超越了该基线。这些结果共同将DPA4置于Matbench Discovery上新的精度-成本帕累托前沿,并使其成为未来多任务大型原子模型(LAM)预训练的有力候选骨干。

英文摘要

Machine-learning interatomic potentials now approach quantum-mechanical accuracy on standard benchmarks, but the training cost of the most expressive equivariant architectures has become a serious bottleneck. We introduce DPA4, an SE(3)-equivariant interatomic-potential architecture with an EMFA (Edge-conditioned, Multi-Focus, Attention) SO(2)-equivariant convolution that combines a low-rank edge-node SO(2)-equivariant product, a multi-focus design for message nonlinearity, and envelope-gated attention for message aggregation. A Lebedev-grid projection further preserves SO(3)-equivariance in the nonlinearity to machine precision. A compiler-friendly conservative energy-gradient training path provides up to $\sim$3 times wall-clock speedup under torch compile. On the compliant Matbench Discovery benchmark, DPA4-Pro attains the best Combined Performance Score (CPS) on the leaderboard, while the 2.76M-parameter DPA4-Air exceeds the accuracy of the 30.1M-parameter eSEN-30M-MP baseline with 10.9$\times$ fewer parameters and 42.9$\times$ less training compute. On SPICE-MACE-OFF, the 5.4M-parameter DPA4-Plus lowers the aggregate molecular energy and force errors of the 6.5M-parameter eSEN baseline by 29% and 30%, while the 2.7M-parameter DPA4-Air still surpasses that baseline with $\sim$2.4$\times$ fewer parameters. Together these results place DPA4 on a new accuracy-cost Pareto frontier on Matbench Discovery and position it as a strong candidate backbone for future multi-task large atomistic model (LAM) pretraining.

2606.02283 2026-06-11 quant-ph 版本更新

Quantum optimal control of the Dicke manifold in dipolar Rydberg atom arrays

里德伯原子阵列中Dicke流形的量子最优控制

Ivy Pannier-Günther, Vikas Buchemmavari, Pablo M. Poggi, Ivan H. Deutsch

AI总结 针对里德伯原子阵列中Dicke流形的控制泄漏问题,提出不可约蒸馏(IRD)方法结合梯度上升脉冲工程(GrAPE),在仅线性缩放希尔伯特维度的截断空间中实现高保真度量子态制备。

Comments 14+5 pages, 12+6 figures

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AI中文摘要

在多体系统中设计和控制量子态的能力是量子信息科学的核心挑战。对于$N$个量子比特的寄存器,完整希尔伯特空间维度呈指数增长$2^N$,使得在没有利用结构或对称性的情况下,通用态制备和控制不可行。一个特别重要且受物理启发的限制是完全对称子空间,由Dicke态张成,这些态是集体自旋$J=N/2$的同时本征态。在二维镊子阵列中通过电偶极子相互作用的里德伯原子系综为实现这种控制提供了有前景的平台。然而,偶极-偶极相互作用的有限范围对生成和控制Dicke流形构成了挑战,因为哈密顿量会导致计算子空间的泄漏。为了抵消这种泄漏,我们根据新开发的“不可约蒸馏”(IRD)方法,在截断希尔伯特空间上执行量子最优控制算法,该方法仅使用线性缩放希尔伯特维度,捕获对称子空间耦合到泄漏误差空间的过程。我们在几乎没有或没有局部寻址的控制方案上实施梯度上升脉冲工程(GrAPE),以生成如Greenberger-Horne-Zeilinger态、Dicke态和极值量子态等资源丰富的态。我们评估每种IRD-GrAPE方案的量子速度极限(QSL),并在小系统尺寸上精确测试脉冲保真度,以及在更大系统上使用高阶IRD预测保真度。

英文摘要

The ability to engineer and control quantum states of many-body systems is a central challenge in quantum information science. For a register of $N$ qubits, the full Hilbert space dimension grows exponentially as $2^N$, rendering generic state preparation and control infeasible without exploiting structure or symmetry. A particularly important and physically motivated restriction is to the fully symmetric subspace, spanned by the Dicke states, which are simultaneous eigenstates of collective spin $J=N/2$. Ensembles of Rydberg atoms interacting via electric dipoles in two-dimensional tweezer arrays form a promising platform for achieving such control. However, the finite range of dipole-dipole interactions poses a challenge to generating and controlling the Dicke manifold because the Hamiltonian incurs leakage from the computational subspace. To counteract this leakage, we perform quantum optimal control algorithms on a truncated Hilbert space according to our newly developed method of ``irrep distillation'' (IRD), which captures the process by which the symmetric subspace couples to leakage error-spaces, using only linear-scaling Hilbert dimension. We implement gradient ascent pulse engineering (GrAPE) on control schemes with little or no local addressing, to generate resourceful states like Greenberger-Horne-Zeilinger, Dicke, and extremal quantum states. We benchmark each scheme of IRD-GrAPE for its quantum speed limit (QSL), as well as exactly testing pulse fidelities on small system sizes and predicting fidelities using higher-order IRD on larger systems.

2606.02220 2026-06-11 eess.AS 版本更新

SiamCTC: Learning Speech Representations through Monotonic Temporal Alignment

SiamCTC: 通过单调时间对齐学习语音表征

SooHwan Eom, Mark Hasegawa-Johnson, Chang D. Yoo

AI总结 提出SiamCTC框架,结合孪生网络与连接时序分类(CTC)损失,通过灵活单调对齐不同时间实现,学习无需严格帧级对应的语音表征,提升对语速变化的鲁棒性。

Comments Accepted to Interspeech 2025

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AI中文摘要

通过孪生网络,自监督语音表征学习取得了显著进展,这些网络利用同一输入的不同视图。然而,现有方法通常需要这些视图之间的帧级对齐,忽略了不同说话风格下更广泛的 linguistic context 不变性。我们引入了SiamCTC,一个将孪生网络与连接时序分类(CTC)相结合的框架,用于学习无需严格帧级对应的语音表征。通过采用CTC损失在相同内容的不同时间实现之间建立灵活、单调的对齐,SiamCTC适应了速度扰动和其他时间增强。这种设计放宽了帧级约束,同时保持了时间一致性,并增强了下游任务中对语速变化的鲁棒性。我们的实验表明,SiamCTC导致了更具适应性的语音表征,特别是在不同的语速下。

英文摘要

Self-supervised speech representation learning has made significant progress through Siamese networks, which leverage different views of the same input. However, existing methods often require frame-wise alignment between these views, overlooking the broader linguistic context invariance across different speaking styles. We introduce SiamCTC, a framework that integrates Siamese networks with Connectionist Temporal Classification (CTC) to learn speech representations without strict frame-level correspondence. By employing CTC loss to establish flexible, monotonic alignments between differing temporal realizations of the same content, SiamCTC accommodates speed perturbations and other temporal augmentations. This design relaxes frame-wise constraints while preserving temporal coherence and enhancing robustness to speaking-rate variations in downstream tasks. Our experiments demonstrate that SiamCTC leads to more adaptable speech representations, particularly at diverse speaking rates.

2606.01983 2026-06-11 physics.optics 版本更新

Polarization-Multiplexed Spatial Differentiation and Filtering Driven by van der Waals Birefringence

介电各向异性诱导的准BIC激活用于全介电超表面的空间微分

Shoumik Debnath, Sudipta Saha

AI总结 通过在对称TiO₂纳米棒对的间隙中插入各向异性BeS层,利用其介电各向异性(Δε≈0.27)放松偶极子抵消条件,实现准BIC共振,并用于一阶空间微分运算。

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AI中文摘要

介电超表面中的准BIC通常通过几何对称破缺获得。这里,在对称TiO₂纳米棒对的间隙中插入一个20 nm的BeS层。BeS层的各向异性(Δε≈0.27)放松了偶极子抵消条件,并产生准BIC共振。二阶微扰理论预测Q ∝ (Δε)^{-2},对于Δn≈0.11,我们获得品质因子Q≈181。准BIC共振给出了在k_x=0处有陷波和180°相位反转的传递函数,两者都是一阶微分的特征。传递函数很好地由Fano模型描述(R²=0.82),并使用USAF 1951分辨率图展示了边缘检测。与传统的通过几何引入对称破缺的准BIC设计不同,这里的扰动来自间隙材料。这使得在保持器件几何结构的同时,通过材料选择实现共振调谐。这些发现确立了光学各向异性作为介电超表面中准BIC工程和模拟光计算的一种实用途径。

英文摘要

We report that the biaxial birefringence of $α$-MoO$_3$ can activate two spectrally distinct quasi-bound states in the continuum (quasi-BICs) within a single symmetric TiO$_2$ nanobar-pair metasurface, with each resonance governed by a different crystallographic axis pair of the van der Waals crystal. With a full 60\,nm $α$-MoO$_3$ gap fill, a TE resonance at 883.9\,nm ($Q=92$, Fano $q=0.090$) and a TM resonance at 923.2\,nm ($Q=31$, Fano $q=0.393$) are obtained. The Q ratio follows the inverse-square permittivity contrast, $Q\propto(Δ\varepsilon)^{-2}$, calibrated across both polarization channels. Oblique-incidence sweeps show that the TE channel acts as a dual-null spatial highpass filter with a broadband stopband ($|H|<0.13$ for $|k_x|\leq0.63\,μ$m$^{-1}$, $T_\mathrm{bg}=0.962$), while the TM channel transfers as $|H|\propto|k_x|$ ($R^2=0.94$), consistent with first-order spatial differentiation. Both operations are verified on a USAF~1951 resolution chart processed in a simulated 4$f$ framework. Channel selection is purely by input polarization angle with no structural modification.

2606.01963 2026-06-11 cs.GT cs.IT math.IT math.PR 版本更新

Improved Amenability Bounds for Local Coordination Games

局部协调博弈的顺应性界改进

Ron Peretz, Dean Kraizberg

AI总结 通过引入与玩家局部输出相关的互信息博弈的Shapley值,改进了局部协调博弈中低效率与图顺应性之间的定量关系,证明了平均分歧不超过ε时图是(O(ε log(1/ε)), r)-顺应性的。

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AI中文摘要

我们研究有限社交网络上的局部纯协调博弈,延续Hutchcroft、Rospuskova和Tamuz的框架。他们表明,局部协调中的低效率迫使底层图是顺应性的,且在顺应性参数上有平方根损失。我们在二元无偏设置中改进了这一损失。利用与玩家局部输出相关的互信息博弈的Shapley值,我们证明如果平均分歧最多为ε,则该图是(O(ε log(1/ε)), r)-顺应性的。这给出了局部协调与图顺应性之间更尖锐的定量逆命题。

英文摘要

We study local pure coordination games on finite social networks, continuing the framework of Hutchcroft, Rospuskova, and Tamuz. They showed that low inefficiency in local coordination forces the underlying graph to be amenable, with a square-root loss in the amenability parameter. We improve this loss in the binary unbiased setting. Using Shapley values of a mutual-information game associated with the players' local outputs, we prove that if the average disagreement is at most $\varepsilon$, then the graph is $(O(\varepsilon\log(1/\varepsilon)),r)$-amenable. This gives a sharper quantitative converse between local coordination and graph amenability.

2606.01854 2026-06-11 stat.ME 版本更新

A Uniform Improvement of the Benjamini-Hochberg Procedure via e-Closure

使用e-闭包对Benjamini-Hochberg方法的统一改进

Jelle Goeman

AI总结 提出closed BH方法,基于e-闭包原理统一改进BH程序,在相同假设下不减少拒绝但增加功效,尤其当假零假设数量大时。

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AI中文摘要

本文提出了closed BH,这是Benjamini和Hochberg(BH)的假发现率控制方法的一种统一改进。Closed BH在BH相同的子集正回归依赖(PRDS)假设下有效。作为一种统一改进,closed BH从不比BH拒绝更少的假设,但它可能拒绝更多。功效的增加尤其当假零假设数量大时观察到。该新方法是使用e-闭包原理构建的,这是最近推导出的多重检验的一般原理。

英文摘要

This paper presents closed BH, a uniform improvement of the False Discovery Rate controlling method of Benjamini and Hochberg (BH). Closed BH is valid under the same assumption of Positive Regression Dependency on a Subset (PRDS) as BH, but also under an alternative and weaker minimal sufficient condition. As a uniform improvement, closed BH never rejects fewer hypotheses than BH, but it may reject quite a few more. An increase in power is observed especially when the number of false null hypotheses is large. The novel method is constructed using the e-Closure principle, a recently derived general principle for multiple testing. The method is implemented in the eClosure package in R.

2606.01650 2026-06-11 q-fin.PM q-fin.TR stat.AP stat.ME 版本更新

Post Selection Estimation of Sharpe Ratios

夏普比率的事后选择估计

Steven E. Pav

AI总结 针对从众多资产中选择具有最高样本内夏普比率的资产,研究基于多面体引理、James-Stein收缩、期望最大夏普比率去偏、阈值法和经验贝叶斯的估计器,并通过模拟评估其偏差、均方根误差和秩相关性。

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AI中文摘要

我们考虑估计一个资产的真实夏普比率的问题,该资产因在众多资产中具有最高的样本内夏普比率而被选中。我们讨论了基于多面体引理、James-Stein收缩、期望最大夏普比率去偏、阈值法和经验贝叶斯的估计器。我们在模拟中测试了这些估计器,计算了不同样本量、资产数量以及总体夏普比率的分布范围和形状下的偏差和均方根误差。我们还计算了估计器与潜在真实值的秩相关性,模拟了这些估计器如何用于比较或排序执行此选择过程的不同团队的结果。我们发现James-Stein估计器在相关参数的许多不同实际值下提供了最佳性能,其次是Jiang和Zhang的GMLEB估计器。这些结果对资产收益的相关性相当稳健,但有一些注意事项。

英文摘要

We consider the problem of estimating the true Sharpe ratio of an asset selected for having the highest observed in-sample Sharpe ratio among many assets. We discuss estimators based on the polyhedral lemma, James Stein shrinkage, debiasing the expected maximum Sharpe ratio, thresholding and empirical Bayes. We test these estimators in simulations, computing bias and root mean square error across different values of sample size, number of assets, and spread and shape of population Sharpe ratios. We also compute rank correlation of the estimators against the underlying quantity, simulating how these estimators might be used to compare or rank the output of different teams which perform this selection process. We find that the James Stein estimator provides the best performance across many different realistic values of the relevant parameters, followed by the GMLEB estimator of Jiang and Zhang. These results are fairly robust to correlation of asset returns, with some caveats.

2606.01235 2026-06-11 cond-mat.supr-con cond-mat.quant-gas 版本更新

Interplay between Quantum Metric and Hybridized Collective Mode in Flat-Band Superfluids

平带超流体中量子度量与杂化集体模的相互作用

Yi Liu, Mingyan Wang, Penghui Hu, Yao Lu

AI总结 通过引入配对(相位和振幅)与密度涨落的耦合动力学,研究平带超流体的集体激发,发现长波极限下仅存在一个低能集体模,其色散系数由平带的正常态量子度量决定。

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AI中文摘要

我们通过引入配对(相位和振幅)与密度涨落的耦合动力学,研究了平带超流体中的集体激发。我们证明,对于任何具有孤立平带的时间反演对称超流体系统,在长波极限下仅出现一个低能集体模。与传统超流体中的线性色散Goldstone模不同,这种杂化模在零动量处无能隙,但在小动量下呈现二次色散($ω\propto q^2$)。解析上,我们揭示该集体模的色散系数由平带的正常态量子度量主导。这些解析预测与数值计算结果高度吻合。我们的结果普遍适用于任何一般的$s$波平带超流体,前提是平带在能量上与其他色散带充分分离。

英文摘要

We investigate collective excitations in flat-band superfluids by incorporating the coupled dynamics of pairing (phase and amplitude) and density fluctuations. We demonstrate that for any time-reversal symmetric superfluid system with an isolated flat band, only a single low-energy collective mode emerges in the long-wavelength limit. In contrast to the linearly dispersive Goldstone mode in conventional superfluids, this hybridized mode is gapless at zero momentum but exhibits a quadratic dispersion ($ω\propto q^2$) at small momenta. We show that the dispersion coefficients of this collective mode are governed by the normal-state quantum metric of the flat band. These analytical predictions are in excellent agreement with numerical calculations. Our results are applicable to any generic $s$-wave flat-band superfluid, provided the flat band is energetically well separated from other dispersive bands.

2606.01183 2026-06-11 cs.DC cs.DB cs.DS cs.PF 版本更新

The World's Fastest Matching Engine Algorithm

世界上最快的撮合引擎算法

Jake Yoon

AI总结 提出Priority-Indicated Node (PIN)和邻域感知树操作两种数据结构,消除订单簿中指针追逐和根到叶搜索的延迟,实现亚微秒级尾部延迟和每秒数千万条消息的处理能力。

Comments 20 pages, 5 figures, 7 tables

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AI中文摘要

每个电子交易所都依赖于一个订单簿,其存储层决定了撮合延迟。主流实现——通过平衡树链接的链表——在每个操作上施加两个成本:指针追逐遍历以到达插入点,以及根到叶搜索以定位目标价格水平。在微突发条件下,这些成本会产生尾部延迟峰值,在流动性最需要时降低市场质量。我们提出了两种数据结构贡献,消除了这些成本。第一种是优先级指示节点(PIN),一种优先队列,其中条目占据固定容量、连续可寻址的槽位,每个槽位携带一个指示条目全局优先级的每槽指示器。与每次操作需要O(log n)次比较的堆不同,PIN直接根据指示器解析插入位置,无需比较条目;指示器更新为O(1),与队列大小无关。第二种解决了更广泛的低效问题:平衡搜索树在每次插入和删除时都进行根到叶搜索,即使调用者已经知道键的中序邻居——例如在有序事件流、增量索引维护和电子交易中。邻域感知插入和删除利用已知的邻居引用,通过O(1)次引用写入来附加或移除节点,然后进行单路径重平衡,统一适用于红黑树、AVL树和B/B+树变体。单个CPU核心在每秒数百万条消息的微突发下,以亚微秒级尾部延迟维持每秒3200万条订单消息,比同一硬件上最好的开源撮合引擎快5-11倍。扩展到单个96核实例,该引擎在10,000个交易品种上维持每秒6.4亿条消息。

英文摘要

A single CPU core sustains 32 million order messages per second at sub-microsecond median end-to-end host-path response latency, 4.7-11 times faster than the best available open-source matching engines on identical hardware. Scaled out, a single 96-core commodity server (~$1,630/month) sustains ~640 million messages per second across 10,000 symbols, over 20 times the provisioned capacity of the U.S. consolidated quote feed. We reach these numbers by attacking the storage layer that sets matching latency. The dominant order-book implementation, linked lists chained through a balanced tree, imposes two costs on every operation: pointer-chased traversal to the insertion point, and root-to-leaf search to locate the target price level. Under micro-bursts these costs produce tail-latency spikes that degrade market quality precisely when liquidity is most needed. We present two data-structure contributions that eliminate them. The first is the Priority-Indicated Node (PIN), a priority queue in which entries occupy fixed-capacity, contiguously addressable slots, with indicators encoding the entry's global priority status. Unlike heaps, which require O(log n) comparisons per operation, the PIN resolves insertion position directly from the indicators without comparing entries; indicator updates are O(1), independent of queue size. A depth-aware capacity model sizes each PIN so hot entries fit within L1 residency. The second targets a broader inefficiency: balanced search trees search from root to leaf on every insertion and deletion, even when the caller already knows the key's in-order neighbors, which in electronic trading are available at zero cost. Neighbor-aware insertion and deletion use known neighbor references to attach or remove a node with O(1) reference writes, followed by single-path rebalancing, across red-black, AVL, and B+-tree variants.

2606.01178 2026-06-11 hep-ph 版本更新

Probing the imaginary parts and their $q^2$ dependences for the tau $g-2$ and EDM

探究τ子g-2和EDM的虚部及其q²依赖性

Xin-Yu Du, Xiao-Gang He, Zhong-Lv Huang, Chia-Wei Liu, Zi-Yue Zou

AI总结 本文通过模型无关的SMEFT和完整的2HDM模型,研究τ子反常磁偶极矩和电偶极矩的q²依赖性及虚部产生机制,提出实验方法提取偶极形状因子的实部和虚部,并表明Belle II和STCF可将a_τ的当前界限提高一个数量级以上。

Comments 18 pages, 6 figures, 2 tables

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AI中文摘要

τ子反常磁偶极矩(MDM) a_τ = (g-2)_τ/2 和电偶极矩(EDM) d_τ 是电弱动力学和可能的新物理源的精确探针,但两者在实验上仍受到弱约束。作为广义形状因子,这些量对于离壳相互作用光子表现出一般的q²依赖性。对于高于τ⁺τ⁻阈值的类时动量转移,q² = s > 4m_τ²,形状因子可以获得吸收性虚部。我们从两个互补的角度研究这种q²依赖性和相关虚部是如何产生的:模型无关的标准模型有效场论(SMEFT)和完整的双希格斯二重态模型(2HDM)。有效框架揭示了a_τ和d_τ之间的密切关联。产生非零d_τ的新CP破坏相互作用通常也会对a_τ产生非零贡献,从而深刻联系它们的现象学研究。在2HDM中,我们证明可以在e⁺e⁻对撞机可达到的水平上产生可观的虚部和显著的q²演化。受这些特征启发,我们提出了提取偶极形状因子实部和虚部的实验方法。利用这些技术,我们表明Belle II和超级τ-粲工厂(STCF)可以将a_τ的当前界限提高一个数量级以上。最后,我们强调结合Belle II和STCF不同质心能量的测量,提供了一种前所未有的途径来明确获取这些偶极形状因子的q²演化信息。

英文摘要

The $τ$ anomalous magnetic dipole moment (MDM) $a_τ= (g-2)_τ/2$ and electric dipole moment (EDM) $d_τ$, are precision probes of electroweak dynamics and possible new physics sources, yet both remain weakly constrained experimentally. Treated as generalized form factors, these quantities exhibit a generic $q^2$ dependence for an off-shell interacting photon. For timelike momentum transfer above the $τ^+τ^-$ threshold, $q^2 = s > 4m_τ^2$, the form factors can acquire absorptive imaginary parts. We investigate how such a $q^2$ dependence and the associated imaginary parts are generated from two complementary perspectives: the model-independent Standard Model Effective Field Theory (SMEFT) and a UV-complete Two-Higgs-Doublet Model (2HDM). The effective framework reveals the intimate correlation between $a_τ$ and $d_τ$. New CP-violating interactions which generate a non-zero $d_τ$, can also generically have non-zero contributions to $a_τ$, thereby deeply linking their phenomenological studies. Within the 2HDM, we demonstrate that sizable imaginary parts and significant $q^2$ running can be generated at levels accessible by $e^+e^-$ colliders. Motivated by these features, we propose experimental methods to extract both the real and imaginary components of the dipole form factors. Utilizing these techniques, we show that Belle II and the Super Tau-Charm Facility (STCF) can improve current bounds on $a_τ$ by more than one order of magnitude. Finally, we highlight that combining measurements across the distinct center-of-mass energies of Belle II and STCF provides a unique, previously unexplored avenue to explicitly obtain information about the $q^2$ evolution of these dipole form factors.

2606.00455 2026-06-11 cs.CR cs.OS 版本更新

Beyond Edge Coverage: Per-Task Data-Flow Extraction at Kernel Function Boundaries via LLVM

超越边覆盖:通过LLVM在核函数边界进行每任务数据流提取

Yunseong Kim

AI总结 提出BOUNDARY FLOW框架,基于LLVM扩展KCOV,在函数边界提取参数和返回值数据流,为内核模糊测试提供状态感知反馈,并支持Rust内核模块,开销低于3%。

Comments Source code and Linux kernel RFC patches for the Boundary Context Extraction framework are publicly available

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AI中文摘要

基于覆盖引导的内核模糊测试工具(如syzkaller)依赖边覆盖(trace-pc)作为唯一的反馈信号。这种上下文无关的方法无法区分仅在参数值上有所不同的执行路径。例如,两次调用copy_from_user(),即使参数size不同,也会命中相同的基本块,但安全含义却大相径庭。我们提出了BOUNDARY FLOW,一个基于LLVM的插桩框架,它扩展了Linux KCOV,实现了函数参数和返回值的数据流提取。一个编译器pass(-fsanitize-coverage=dataflow-args, dataflow-ret)在函数入口处发出轻量级回调,捕获结构化元组<PC, arg_idx, arg_size, ptr, offsets[]>,在返回时捕获<PC, ret_size, ptr, offsets[]>。复合类型通过DWARF DICompositeType元数据自动分解,无需源代码注释。一个独立的内核设备(/sys/kernel/debug/kcov_dataflow)提供无锁的每任务环形缓冲区,不会干扰现有的KCOV或syzkaller基础设施。我们展示了双重用途:模糊测试工具获得状态感知反馈,用于指导进入值依赖状态转换的变异;安全分析师获得确定性的参数记录,用于根本原因分析,而无需printk或kprobe开销。一个编译后流水线(rustc, opt, llc)使得Rust内核模块插桩成为可能,无需修改rustc,这是在drgn/vmcore因-O2 DWARF省略而失败的情况下捕获Rust函数参数的唯一运行时方法。在五类漏洞(越界、释放后使用、双重释放、10层深度链传播、Rust FFI、Rust for Linux模块)上评估,插桩路径的开销低于3%。

英文摘要

Coverage-guided kernel fuzzers such as syzkaller rely on edge coverage (trace-pc) as their sole feedback signal. This context-blind approach cannot distinguish execution paths that differ only in argument values -- for example, two invocations of copy_from_user() with different size parameters hit identical basic blocks yet have vastly different security implications. I present TOOLNAME, an LLVM-based instrumentation framework that extends Linux KCOV with data-flow extraction of function arguments and return values. A compiler pass emits lightweight callbacks capturing structured tuples of program counter, argument metadata, and field values at function entry and return. Composite types are automatically decomposed via DWARF DICompositeType metadata with zero source annotation. A lock-free per-task ring buffer delivers records to user space with no interference to existing KCOV or syzkaller infrastructure. I demonstrate dual utility: (1) fuzzers gain state-aware feedback for mutation guidance into value-dependent state transitions, and (2) security analysts obtain deterministic argument records for root-cause analysis without printk or kprobe overhead. Two Rust instrumentation paths are provided: a post-compilation pipeline requiring no rustc modification, and native instrumentation via rustc built against the custom LLVM -- both the only runtime methods for capturing Rust function arguments given that drgn/vmcore fails under -O2 DWARF elision.

2606.00389 2026-06-11 math.AP 版本更新

Strichartz Estimates and Small-Mass Global Well-Posedness for the Periodic Quintic NLS in 1D

一维周期五次非线性薛定谔方程的Strichartz估计与小质量全局适定性

Nikolaos Skouloudis, Jiahui Yu

AI总结 本文通过建立新的无导数损失的$L^6_{t,x}$ Strichartz估计,结合$I$-方法,证明了周期五次非线性薛定谔方程在$H^s(\mathbb{T})$ ($s>0$)中的小质量全局适定性。

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AI中文摘要

我们考虑周期五次非线性薛定谔方程,并证明了在$H^s(\mathbb{T})$ ($s>0$)中的小质量全局适定性。证明依赖于一个新的无导数损失的$L^6_{t,x}$ Strichartz估计,该估计通过高低方法、非对称超水平集估计和新的精细宽窄论证建立。尽管我们的$L^6_{t,x}$ Strichartz估计不是最优的,仅在比最优对数尺度稍短的时间尺度上有效,但将其与$I$-方法结合,可以将局部解延拓到任意时间。

英文摘要

We consider the periodic quintic nonlinear Schrödinger and prove small-mass global well-posedness in $H^s(\mathbb{T})$ for $s>0$. The proof relies on a new derivative-loss-free $L^6_{t,x}$ Strichartz estimate which is established using the high-low method, an asymmetric superlevel set estimate and a new refined broad-narrow argument. Although our $L^6_{t,x}$ Strichartz estimate is not sharp, being valid on slightly shorter time scales than the optimal logarithmic scale, combining it with the $I$-method enables the extension of local solutions to arbitrary times.

2606.00283 2026-06-11 math.OC math.MG 版本更新

The Brøndsted-Rockafellar theorem in geodesic spaces

测地空间中的Brøndsted-Rockafellar定理

Alberto Domínguez Corella, Alejandro Villegas-Acuña

AI总结 本文在一般测地度量空间中给出了Brøndsted-Rockafellar定理的构造性版本,并应用于Caristi定理的构造形式以及度量斜率误差界与泛函全局增长之间的定量关系。

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AI中文摘要

我们在一般测地度量空间中给出了Brøndsted-Rockafellar定理的一个构造性版本。应用包括Caristi定理的一个构造性形式以及度量斜率误差界与泛函全局增长之间的定量关系。

英文摘要

We present a constructive version of the Brøndsted-Rockafellar theorem in general geodesic metric spaces. Applications include a constructive form of the Caristi theorem and quantitative relations between metric slope error bounds and the global growth of functionals.

2605.31416 2026-06-11 math.ST math.PR stat.TH 版本更新

Second-order PACF asymptotics and discrimination between fractional Gaussian noise and $\FARIMA(0,d,0)$

二阶PACF渐近性及分数高斯噪声与$\FARIMA(0,d,0)$的区分

Chunhao Cai

AI总结 通过推导分数高斯噪声(fGn)的偏自相关函数(PACF)的二阶渐近展开,揭示了其与$\FARIMA(0,d,0)$在二阶非通用阶上的差异,并解释了短记忆阶选择差异的原因。

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AI中文摘要

分数高斯噪声和$\FARIMA(0,d,0)$具有相同的长记忆极点$|\theta|^{-2d}$,因此具有相同的主导PACF律$\alpha(n)\sim d/n$。我们证明这种一致性在第一个非通用阶上被打破。对于$0<d<1/2$,纯fGn的PACF满足$$ \alpha_{\fGn}(n)=\frac d n+\frac{C_{\fGn}(d)}{n^2}+o(n^{-2}), \qquad C_{\fGn}(d)<d^2, $$ 证明使用了Bingham--Inoue--Kasahara表示、fGn的相位系数展开和Hankel算子摄动论证。因此,fGn谱包络在一阶不可见,但在二阶有限预测中可见,这解释了当fGn数据由FARIMA型模型拟合时短记忆阶选择可能不同的原因。

英文摘要

Fractional Gaussian noise and $\FARIMA(0,d,0)$ have the same long-memory pole $|θ|^{-2d}$ and hence the same leading PACF law $α(n)\sim d/n$. We show that this agreement breaks at the first non-universal order. For $0<d<1/2$, the pure fGn PACF satisfies $$ α_{\fGn}(n)=\frac d n+\frac{C_{\fGn}(d)}{n^2}+o(n^{-2}), \qquad C_{\fGn}(d)<d^2, $$ The proof uses the Bingham--Inoue--Kasahara representation, a phase-coefficient expansion for fGn, and a Hankel-operator perturbation argument. Thus the fGn spectral envelope is invisible at first order but visible in second-order finite prediction, explaining why short-memory order selection can differ when fGn data are fitted by FARIMA-type models.

2605.31046 2026-06-11 physics.space-ph astro-ph.EP astro-ph.IM physics.plasm-ph 版本更新

Extreme, transient bursts of energy in the auroral ionosphere. I. Predictive radar tracking

雷达极光预测跟踪揭示2024年5月G5风暴期间超过500 mV/m的电场爆发

Magnus F Ivarsen, Saif Marei, Jordan Cho, Jean-Pierre St-Maurice, Glenn C Hussey

AI总结 本文提出一种基于ICE BEAR VHF雷达的Farley-Buneman波跟踪方法,通过匈牙利算法和卡尔曼滤波实现极光簇的关联与运动预测,并在2024年5月G5风暴中检测到约560 mV/m的极端电场爆发。

Comments 21 pages, 9 figures

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AI中文摘要

E区雷达极光的整体运动提供了稀疏分布、直接的电场测量,表现为间歇性爆发。我们提出了一种针对ICE BEAR VHF雷达测量的Farley-Buneman波的跟踪程序。每个簇用α-形状表示;帧间关联是匈牙利线性分配问题,代价结合质心距离和形状交并比;运动预测为退化卡尔曼滤波。监测簇的生成、消亡、分裂和合并;每个跟踪轨迹通过分段线性回归简化为每段速度。我们通过与2021年5月20日的国防气象卫星计划(DMSP)联合观测和Swarm离子漂移统计进行验证。在2024年5月10日的G5风暴期间,在闭合的日侧场线上,该方法恢复了一个五秒簇,速度为11,240±660 m/s,对应约560 mV/m——超过了已记录的亚极光热发射速度和最极端的亚极光漂移报告。该检测与极端电场结构表现为短时爆发现象一致。

英文摘要

The bulk motion of E-region radar aurora provides a sparsely distributed, direct measurement of the ionospheric electric field in intermittent bursts. We present a tracking procedure for \textsc{icebear} VHF measurements of Farley-Buneman waves. Each cluster is represented as an $α$-shape; frame-to-frame association is a Hungarian linear-assignment problem with a cost combining centroid distance and shape Intersection-over-Union; kinematic prediction amounts to a degenerate Kalman filter. Births, deaths, splits, and mergers are monitored; each tracked trajectory is reduced to per-segment velocities by piecewise-linear regression. We validate against \textit{in-situ} observations. During the G5 storm of 10 May 2024, on closed dayside field-lines, our method recovers a five-second cluster moving at $11{,}240\pm660$~m/s, implying an electric field strength of $\approx 560$~mV/m, a value that exceeds documented sub-auroral thermal emission speeds and the most extreme reported sub-auroral drifts. The detection is consistent with extreme E-field structures appearing as short-lived bursts, representing field variability, and we provide parameterizations of this variability for space weather modeling.

2605.30796 2026-06-11 math.NA cs.NA 版本更新

Lightning Plus Polynomial Approximation: Optimal Root-Exponential Convergence for Singular Functions in Corner Domains

闪电加多项式逼近:角域中奇异函数的最优根指数收敛

Shuhuang Xiang, Jun Xiang, Shunfeng Yang, Yuee Zhong

AI总结 针对角域中的奇异函数,本文提出闪电加多项式逼近方案,采用锥形指数聚类极点,并证明其达到最优根指数收敛速率。

Comments 38 pages, 10 figures

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AI中文摘要

本文对闪电加多项式逼近方案进行了严格的收敛性分析,该方案使用带有锥形指数聚类极点的有理逼近。这种极点放置策略最初由Trefethen及其合作者提出,用于解决角点奇异性。我们建立了形式为 $g(z)z^α$ 或 $g(z)z^α\log z$ 的原型函数类的最优根指数收敛性,其中 $g$ 在解域的邻域内解析。本文所得结果证实了 [SIAM J. Numer. Anal., 61:2580-2600, 2023] 中提出的猜想3.1和5.3,并表明选择 $σ_{\mathrm{opt}} =\frac{\sqrt{2(2 -β)}π}{\sqrtα}$ 可实现理论最优收敛速率 $\mathcal{O}\left(e^{-\sqrt{2(2 - β)Nα}π}\right)$。特别地,对于 $β= 0$ 的特例,所提方案达到了与 Stahl 建立的 $[0,1]$ 上 $x^α$ 的最佳有理逼近相同的最优收敛速率。此外,在 Gopal 和 Trefethen 提出的角域分解框架内,本文严格证明了闪电加多项式逼近问题的最优根指数收敛性,并显式推导了最优极点聚类参数。

英文摘要

This paper presents a rigorous convergence analysis for the lightning plus polynomial approximation scheme, which employs rational approximations constructed with preassigned tapered, exponentially clustered poles. This pole placement strategy was originally introduced by Trefethen and his collaborators for the resolution of corner singularities. Ample numerical results indicate that this scheme achieves root-exponential convergence, and in particular attains the same optimal convergence rate as the best rational approximation to $x^α$ on $[0,1]$ established by Stahl.% which is conjectured in [SIAM J. Numer. Anal., 61:2580-2600, 2023]. In this work, we establish optimal root-exponential convergence for the class of prototype functions of the form $g(z)z^α$ or $g(z)z^α\log z$, where $g$ is analytic on a neighborhood of the sector domain. These results confirm the validity of Conjectures 3.1 and 5.3 stated in [SIAM J. Numer. Anal., 61:2580-2600, 2023], and demonstrate that the choice $σ_{\mathrm{opt}} =\frac{\sqrt{2(2 - β)}π}{\sqrtα}$ achieves the theoretically optimal convergence rate $\mathcal{O}\left(e^{-\sqrt{2(2 - β)Nα}π}\right)$. Notably, for the specific case of $β= 0$, the scheme recovers Stahl's optimal convergence rate for $x^α$. Furthermore, working within the decomposition framework for corner domains proposed by Gopal and Trefethen, this paper provides a rigorous proof of optimal root-exponential convergence for lightning plus polynomial approximation problems, and explicitly derives the optimal pole clustering parameter.

2605.27307 2026-06-11 math.CO 版本更新

Triangle Families with Large Edge Up-Laplacian Spectral Gap

具有大边-上拉普拉斯谱间隙的三角形族

Mutasim Mim

AI总结 本文研究有限三角形族中边-三角形关联矩阵的谱间隙,证明大谱间隙迫使支撑图中每条边出现在至少⌈λ⌉-2个三角形中且最小度至少⌈λ⌉-1,并揭示了完全三系统是唯一的最小谱极值族,但谱间隙在连续团阈值之间呈孤立峰值。

Comments 22 pages

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AI中文摘要

设$\mathcal{T}$是全序集$V$的$3$元子集构成的有限非空集合。我们将$\mathcal{T}$视为支撑图中的三角形集合。令$δ_{1,\mathcal{T}}$为符号边-三角形关联矩阵,$λ(\mathcal{T})$为$δ_{1,\mathcal{T}}^Tδ_{1,\mathcal{T}}$的谱间隙。 我们的主要结果表明,大的$λ(\mathcal{T})$迫使支撑图中存在强重叠和大最小度。特别地,每条支撑边至少属于$\mathcal{T}$中的$\lceil λ(\mathcal{T})\rceil-2$个三角形,因此图的最小度至少为$\lceil λ(\mathcal{T})\rceil-1$。我们进一步证明$\binom{n}{3}$是达到水平$n$的精确阈值:若$|\mathcal{T}|< \binom{n}{3}$,则$λ(\mathcal{T}) \leq n-1$;而若$|\mathcal{T}|=\binom{n}{3}$且$λ(\mathcal{T}) > n-1$,则$\mathcal{T}$恰好是$n$顶点团上的所有三角形集合。此外,这个团峰值在强区间尺度意义下是孤立的:令$ϕ(t)=\max_{|\mathcal{T}|=t} λ(\mathcal{T})$,在$\binom{n}{3}$之上立即存在一个禁止区间,其上$ϕ(t) \leq n-1$,并且首次超过水平$n-1$被延迟了$Θ(n^2)$个额外三角形。由于$\binom{n+1}{3} - \binom{n}{3}=Θ(n^2)$,这意味着在$\binom{n}{3}$处的峰值之后,必须遍历整个间隙的非零比例才能到达下一个团阈值,从而发生实质性恢复。特别地,$ϕ$不是单调的。然而,$ϕ(t)=Θ(t^{\frac{1}{3}})$。 最后,若$Λ(t):=\max_{1 \leq s \leq t}ϕ(s)$,则$Λ(t)=\max\{n \in \mathbb{N}:\binom{n}{3} \leq t\}$。因此完全三系统是唯一的最小谱极值族,但它们的峰值在连续团阈值之间的自然尺度上是孤立的。

英文摘要

Let $\mathcal{T}$ be a finite nonempty set of $3$-element subsets of a totally ordered set $V$. We view $\mathcal{T}$ as the set of triangles in the support graph. Let $δ_{1,\mathcal{T}}$ be the signed edge-triangle incidence matrix, and $λ(\mathcal{T})$ the spectral gap of $δ_{1,\mathcal{T}}^Tδ_{1,\mathcal{T}}.$ Our main results show that large $λ(\mathcal{T})$ forces strong overlap and a large minimum degree in the support graph. In particular, every support edge lies in at least $\lceil λ(\mathcal{T})\rceil-2$ triangles in $\mathcal{T}$ and hence the graph has minimum degree at least $\lceil λ(\mathcal{T})\rceil-1$. We further prove that $\binom{n}{3}$ is the exact threshold for attaining level $n:$ if $|\mathcal{T}|< \binom{n}{3}$, then $λ(\mathcal{T}) \leq n-1,$ while if $|\mathcal{T}|=\binom{n}{3}$ and $λ(\mathcal{T}) > n-1,$ then $\mathcal{T}$ is exactly the full set of triangles on an $n$-vertex clique. Moreover, this clique peak is isolated in a strong interval-scale sense: letting $ϕ(t)=\max_{|\mathcal{T}|=t} λ(\mathcal{T})$, immediately above $\binom{n}{3}$ there is a forbidden interval on which $ϕ(t) \leq n-1$, and the first passage above the level $n-1$ is delayed by $Θ(n^2)$ additional triangles. Since $\binom{n+1}{3} - \binom{n}{3}=Θ(n^2),$ this implies that after the peak at $\binom{n}{3}$ one must traverse a nonzero proportion of the full gap until the next clique threshold before substantial recovery can occur. In particular, $ϕ$ is not monotone. However, $ϕ(t)=Θ(t^{\frac{1}{3}}).$ Finally, if $Λ(t):=\max_{1 \leq s \leq t}ϕ(s),$ then $Λ(t)=\max\{n \in \mathbb{N}:\binom{n}{3} \leq t\}.$ Thus complete triple systems are the unique minimal spectral extremizers, but their peaks are isolated on the natural scale between consecutive clique thresholds.

2605.27303 2026-06-11 eess.SP 版本更新

Point Spread Function Optimization for Communication-assisted UAV-borne MIMO TomoSAR

面向通信辅助的无人机载MIMO TomoSAR的点扩展函数优化

Pouya Fakharizadeh, Mohamed-Amine Lahmeri, Gerhard Krieger, Robert Schober

AI总结 针对无人机载MIMO合成孔径雷达层析成像系统,提出基于粒子群优化的联合无人机编队与卸载功率分配方法,以最小化点扩展函数旁瓣水平。

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AI中文摘要

本文解决了无人机载多输入多输出合成孔径雷达层析成像系统的点扩展函数优化问题。部署一群无人机载SAR系统对区域成像以获取其高度剖面。为了获得场景的高质量三维图像,PSF必须具有低旁瓣。图像生成所需的重计算在地面进行。为此,无人机SAR收集的传感器数据通过频分多址空地回程链路实时卸载。本文联合优化无人机编队和用于卸载的功率分配,以最小化PSF旁瓣水平。为此,我们提出了一种基于粒子群优化算法的新颖解决方案,该方案满足实际的感知和通信约束。仿真结果表明,与几种基准方案相比,所提方案能显著改善旁瓣抑制。

英文摘要

This paper tackles the optimization of the point spread function (PSF) of unmanned aerial vehicle (UAV)-borne multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) tomography systems. A swarm of UAV-borne SAR systems is deployed to image an area to obtain its height profile. To achieve a high-quality three-dimensional (3D) image of the scene, the PSF has to exhibit low sidelobes. The heavy computations, required for image generation, are performed on the ground. To this end, the sensor data collected by the UAV-SARs is offloaded in real time via a frequency division multiple access (FDMA) air-to-ground backhaul link. In this work, the UAV formation and the power allocated for offloading are jointly optimized for the minimization of the PSF sidelobe levels. To this end, we propose a novel solution based on the particle swarm optimization (PSO) algorithm, which meets practical sensing and communication constraints. Our simulation results demonstrate that the proposed solution can significantly improve sidelobe suppression compared to several benchmark schemes.

2605.26435 2026-06-11 cond-mat.mtrl-sci cs.NA math.NA physics.comp-ph 版本更新

Gradient-Based Topology Optimization of Localized Defect Modes with Bandgap Preservation in Phononic Crystals

通过拓扑优化实现声子晶体缺陷模的直接色散曲线工程以获取指定频率

Xinlin Xu, Junji Kato

AI总结 提出一种两阶段拓扑优化框架,通过基于高斯加权选择函数的多目标优化,在声子晶体中精确设计缺陷模频率,同时抑制带隙内竞争模式。

Comments Updated manuscript title, abstract, and text to match the journal submission version

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AI中文摘要

声子晶体通过工程带隙实现对弹性波传播的精确操控;然而,在带隙内设计用于频率选择性应用的缺陷态仍然是一个重大挑战。现有的设计方法,包括先前的优化公式,难以系统性地解决将所需缺陷模吸引到目标频率同时排斥带隙区域内不需要模式这一相互竞争的目标。这种抑制竞争模式的能力不足常常导致带隙内出现虚假的、不期望的谐振模式,从而限制了设计的纯净度。本文提出了一种新颖的两阶段拓扑优化框架,通过基于高斯加权选择函数的创新多目标公式来解决这一挑战。在第一阶段,优化单胞拓扑以在目标频率周围创建宽带隙。在第二阶段,使用一个专门设计的目标函数优化包含缺陷的超胞,该目标函数通过具有自适应σ参数的选择函数S(ω)动态平衡模式吸引和排斥。这种选择机制使优化器能够自动识别并选择性地吸引最合适的缺陷模,同时排斥带隙区域内的竞争模式,无需手动模式跟踪。数值示例表明,所提出的框架成功生成了具有工程缺陷态的声子晶体,这些缺陷态在宽带隙内产生精确定位的局域谐振模式,具有指定频率,可应用于频率选择性滤波器和弹性波操控器件。

英文摘要

Phononic crystals can confine elastic waves through localized defect states within bandgaps, offering promising opportunities for vibration control and energy localization. However, designing defect states at prescribed frequencies while maintaining adequate separation from other in-gap modes remains a significant challenge. Existing optimization approaches generally treat the target mode indirectly and provide limited control over competing localized modes. This study presents a gradient-based two-stage topology optimization framework for the frequency placement of localized defect modes in periodic elastic media. First, a host unit cell is optimized to create a bandgap around a prescribed frequency. Subsequently, only the defect cell is modified to attract a selected localized mode toward the target frequency while repelling non-target modes away from the central region of the bandgap. The formulation incorporates a smooth mode-selection function that combines mode attraction and repulsion within a unified objective, enabling automatic tracking of the relevant modes throughout the optimization process. Because the localized defect branches of interest are nearly flat, the optimization is performed using only the $Γ$-point eigenspectrum, while the corresponding dispersion relations over a reduced irreducible Brillouin zone are evaluated afterwards for verification. Numerical examples involving two material systems and two supercell sizes demonstrate accurate placement of localized resonances, clear separation from competing in-gap modes, and substantial preservation of the host bandgap. The resulting structures exhibit strong elastic-wave localization, highlighting the potential of the proposed approach for the design of phononic devices for vibration confinement and energy trapping.

2605.26231 2026-06-11 cond-mat.quant-gas 版本更新

Competition between pair and single-particle superfluidity in bosonic quasi-flat bands: A Gaussian state approach

玻色准平带中配对超流与单粒子超流的竞争:高斯态方法

Maxime Burgher, Simon Loddo, Laurens Vanderstraeten, Nathan Goldman, Ivan Amelio

AI总结 通过高斯态方法研究一维准平带模型中配对超流与单粒子超流的竞争,发现配对超流在有限跳跃强度下稳定存在,并推导出声速与量子几何核的普遍关系。

Comments v2: integrated refs

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AI中文摘要

相互作用与量子几何之间的相互作用可以驱动弱色散玻色子进入不同的奇异多体相。在这项工作中,我们研究了一维准平带模型,该模型在全平带极限下表现出扩展的配对超流相。引入单粒子跳跃导致与更常规的单粒子超流的竞争:我们发现配对超流在有限范围的跳跃强度内保持稳定,直到系统最终转变为常规超流相。在我们的研究中,我们利用变分高斯态方法,该方法提供了单粒子和配对超流相的统一描述,涉及基态波函数和集体激发谱。特别地,我们推导出声速与“量子几何核”之间的普遍关系,从而扩展了先前依赖于单粒子平均场理论的量子度量联系。该方法结合双玻色子问题和精确对角化的见解,绘制了模型的完整相图。我们的结果表明,高斯态方法是研究多轨道晶格中相互作用玻色子的广泛超流相的多功能工具。

英文摘要

The interplay between interactions and quantum geometry can drive weakly dispersive bosons into different exotic many-body phases. In this work we study a quasi flat-band model in one dimension that exhibits an extended pair-superfluid phase in the all-flat-band limit. Introducing single-particle hopping leads to an intriguing competition with a more conventional single-particle superfluid: we find that the pair superfluid remains stable for a finite range of the hopping strength until the system eventually transitions into the conventional superfluid phase. In our study, we make use of a variational Gaussian state approach that provides a unified description of the single-particle and pair superfluid phases, regarding both the ground state wavefunction and the collective excitation spectrum. In particular, we derive a general relation between the speed of sound and a ``quantum geometric kernel'', thereby extending earlier connections to the quantum metric, which relied on single-particle mean-field theory. This approach is combined with insights from the two-boson problem and exact diagonalization to map out the full phase diagram of the model. Our results show that the Gaussian approach is a versatile tool for studying a broad range of superfluid phases of interacting bosons in multi-orbital lattices.

2605.23302 2026-06-11 astro-ph.GA 版本更新

Rotation-curve residuals reveal a suppressed acceleration branch in dwarf galaxies

旋转曲线残差揭示矮星系中受抑制的加速度分支

Hosik Lee

AI总结 通过分析SPARC和LITTLE THINGS样本的旋转曲线残差,发现残差遵循简单的经验形式,且矮星系中残差截距受抑制,表明残差具有种群依赖性结构。

Comments The manuscript is replaced by arXiv:2606.05540 of more robust data

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AI中文摘要

星系旋转曲线表现出与仅从可见物质推断的牛顿预期之间的系统性偏差。现有的唯象描述捕捉了这些偏差的许多方面,但大质量盘星系和矮不规则星系之间共同的残差结构仍不清楚。我们研究了旋转曲线残差是否在SPARC和LITTLE THINGS样本中组织成简单的经验形式。我们分析了175个SPARC星系和22个LITTLE THINGS矮不规则星系的速度平方空间,在减去一个领先的牛顿项之后。我们拟合了一个广义残差族,v^2-A/r=B+Cr^{q+1},并检查数据选择了哪种径向标度。星系种群系统地倾向于极限q≈0,对应于近似线性的残差关系,v^2-A/r=B+Cr。SPARC星系通常占据高B分支,而LITTLE THINGS矮星系显示出受抑制的残差截距,包括几个与B=0一致的星系。对于SPARC样本,高B分支近似遵循B∝M_bar^{0.72}。旋转曲线残差并非领先牛顿贡献之外的无特征散点,而是在大质量和矮星系系统中显示出简单的种群依赖性经验组织。

英文摘要

Galaxy rotation curves exhibit systematic deviations from the Newtonian expectation inferred from visible matter alone. Existing phenomenological descriptions capture many aspects of these deviations, but a common residual structure across massive disks and dwarf irregular galaxies remains unclear. We investigate whether rotation-curve residuals organize into a simple empirical form across the SPARC and LITTLE THINGS samples. We analyze 175 SPARC galaxies and 22 LITTLE THINGS dwarf irregular galaxies in velocity-squared space after subtracting a leading Newtonian-like term. We fit a generalized residual family, v^2-A/r=B+Cr^{q+1}, and examine which radial scaling is selected by the data. The galaxy population systematically favors the limit \(q\simeq0\), corresponding to an approximately linear residual relation, \(v^2-A/r=B+Cr\). SPARC galaxies generally occupy a high-\(B\) branch, whereas LITTLE THINGS dwarf galaxies show suppressed residual intercepts, including several systems consistent with \(B=0\). For the SPARC sample, the high-\(B\) branch approximately follows \(B\propto M_{\rm bar}^{0.72}\). {Rotation-curve residuals are not featureless scatter beyond the leading Newtonian-like contribution, but instead show a simple population-dependent empirical organization across massive and dwarf galaxy systems.}

2605.30296 2026-06-11 physics.atom-ph 版本更新

Enhanced Loading of a Molecular Magneto-Optical Trap

增强分子磁光阱的装载

Ebram Youssef, Kaiya Wilson, Jiahe Cao, Reilly Brislawn, Avani Lakkireddy, Kun Liu, Aaron Teo, Phoebe Turner, Loïc Anderegg

AI总结 通过随机薛定谔方程蒙特卡洛方法模拟CaF直流磁光阱,识别限制捕获速度的关键因素和损失机制,并实验实现八倍改进,获得150万个捕获分子。

Comments 17 pages, 19 figures. Added a figure and discussion on capture velocity in large MOT beams to Appendix C

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AI中文摘要

分子磁光阱(MOT)通常捕获的粒子数量比原子磁光阱少几个数量级,部分原因是其捕获速度显著较低。这里,我们采用随机薛定谔方程蒙特卡洛方法对CaF直流MOT进行建模,以理解限制捕获速度的因素。我们提供了影响捕获速度的机制的物理直觉,并确定了改进捕获速度的重要参数和通用策略。此外,我们指出了分子MOT固有的损失机制,并确定了实验上应避免的参数范围。我们将模拟结果与CaF直流MOT进行基准测试,并实验实现了模型预测的改进。通过这样做,我们展示了具有150万个捕获分子的分子MOT。这代表了八倍的改进,并且是朝着实现激光冷却分子量子简并的重要一步。

英文摘要

Molecular magneto-optical traps (MOTs) typically capture orders of magnitude fewer particles than their atomic counterparts due in part to their significantly lower capture velocities. Here, we employ a Stochastic Schrödinger Equation Monte Carlo approach to model a CaF DC MOT to understand the factors limiting capture velocity. We provide physical intuition into the mechanisms that affect capture velocity and identify important parameters and general strategies to improve it. In addition, we point out a loss mechanism intrinsic to molecular MOTs and determine parameter regimes that should be avoided experimentally. We benchmark our simulations against a CaF DC MOT and experimentally implement the improvements predicted by our model. In doing so, we demonstrate a molecular MOT with 1.5 million trapped molecules. This represents an eight-fold improvement and is an important step toward achieving quantum degeneracy with laser cooled molecules.

2605.29904 2026-06-11 astro-ph.SR astro-ph.GA 版本更新

Evidence of triggered star formation in the Pillars of Creation from JWST observations

JWST观测揭示创生之柱中触发式恒星形成的证据

Jing Wen, Bingqiu Chen, Jian Gao, Jun Li, Ming Yang, Biwei Jiang

AI总结 利用JWST高分辨率观测,在创生之柱中发现253个年轻恒星候选体,其空间分布与反馈驱动结构边界相关,暗示部分恒星可能由触发式形成机制产生。

Comments This is the author accepted manuscript of an article published in Nature Astronomy. The final published version is available at https://doi.org/10.1038/s41550-025-02683-8. Updated to include the JWST/MAST acknowledgement and DOI

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Journal ref
Nature Astronomy 9, 1845-1853 (2025)
AI中文摘要

恒星在分子云中形成,受其局部环境影响,但大质量恒星反馈在触发或抑制恒星形成中的作用仍是天体物理学的基本问题。鹰状星云中的创生之柱由NGC 6611中大质量恒星的电离辐射和恒星风塑造,为研究这一问题提供了天然实验室。本文利用JWST近红外相机和中红外仪器对创生之柱进行高分辨率观测,揭示了253个年轻恒星候选体(YSO)。这些YSO候选体在空间上与反馈驱动结构的边缘相关,沿边界存在超密度。初步观测到恒星年龄随距离电离源增加而减小的微弱趋势。在过去1 Myr内,该区域的恒星形成速率似乎有所增强。这种年龄和空间关联表明,虽然大部分YSO可能与中心星团同时形成,但其中一部分可能与触发式恒星形成有关。JWST图像中精细的结构,包括柱I和柱II顶端的螺旋状盘和双反射星云,进一步凸显了恒星形成过程的复杂性。

英文摘要

Stars form in molecular clouds under the influence of their local environments, yet the role of massive stellar feedback in either triggering or suppressing star formation remains a fundamental question in astrophysics. The Pillars of Creation in the Eagle Nebula, sculpted by ionizing radiation and stellar winds from massive stars in NGC 6611, offer a natural laboratory for investigating this question. Here we present high-resolution observations of the Pillars of Creation using the JWST Near Infrared Camera and Mid-Infrared Instrument, revealing 253 young stellar object (YSO) candidates. These YSO candidates show spatial correlations with the edges of feedback-driven structures, with overdensities along the boundaries. A weak trend of decreasing stellar age with increasing distance from the ionizing source was tentatively observed. There also appears to be an enhancement in the star formation rate within the past 1 Myr in this region. Such age and spatial associations suggest that while the bulk of the YSOs may have formed contemporaneously with the central cluster, a subset could be associated with triggered star formation. The JWST image of intricate structures, including a spiral-like disk and bi-reflection nebulae at the tips of Pillar I and Pillar II, further highlights the complexity of star formation processes.

2603.07960 2026-06-11 nucl-th 版本更新

Centrifugal-corrected harmonic oscillator model for spherical proton emitters

球形质子发射体的离心修正谐振子模型

Xiao-Yan Zhu, Wei Gao, Jia Liu, Li-Qiang Zhu, Wen-Bin Lin, Xiao-Hua Li

AI总结 提出一种改进的谐振子模型,通过引入离心势修正项,系统评估球形原子核的质子放射性半衰期,并利用实验数据拟合得到离心参数和核势深度,验证了归一化宽度对数与碎裂势的线性关系,推导出离心势可调参数的解析表达式,提高了质子放射性研究的精度。

Comments 22 pages, 5 figures, version accepted for publication in Eur. Phys. J. Plus

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AI中文摘要

在本工作中,我们提出了一种改进的谐振子模型,通过引入离心势效应,系统评估球形原子核的质子放射性半衰期。通过拟合实验数据,得到修正项 $dl(l+1)$ 的离心参数 $d = 0.143$ 和核势深度 $V_0 = 62.4$ MeV。该模型结合了基于 DD-ME2 力的相对论平均场(RMF)理论和 BCS 方法,以确定谱因子 $S_p$。此外,通过验证归一化宽度对数 $\log_{10}{γ^2}$ 与碎裂势 $V_{frag}$ 之间的线性关系,确认了核结构与隧穿动力学之间的联系,并推导出离心势对应的可调参数 $d$ 的解析表达式为 $d^{ m{Ae}}$ $\approx$ 0.167。与 $d^{ m{Ae}}$ 相比,基于 $d$ 的修正模型得到的结果与实验半衰期更吻合,并能将实验数据的误差控制在 2.4 倍以内。此外,扩展后的改进模型被用于预测 NUBASE2020 中一些能量允许或已观测到但尚未量化的可能质子放射性候选核的半衰期。本工作提高了质子放射性研究的精度,并为未来的核结构研究提供了稳健的理论框架。

英文摘要

In the present work, we propose an improved harmonic oscillator model to systematically evaluate the proton radioactivity half-lives in spherical nuclei, incorporating centrifugal potential effects. By fitting the experimental data, the centrifugal parameter $d = 0.143$ for the correction term $dl(l+1)$ and nuclear potential depth $V_0 = 62.4$ MeV are obtained. The model integrates the relativistic mean field (RMF) theory with the BCS method based on the DD-ME2 force to determine spectroscopic factors $S_p$. Moreover, by verifying the linear relationship between the logarithm of the normalized width $\log_{10}{γ^2}$ and fragmentation potential $V_{frag}$, the connection between nuclear structure and tunneling dynamics is confirmed, and an analytical expression for the adjustable parameter $d$ corresponding to the centrifugal potential is derived as $d^{\rm{Ae}}$ $\approx$ 0.167. Compared with $d^{\rm{Ae}}$, the modified model based on $d$ yields results in better agreement with experimental half-lives, and is able to control the error of the experimental data within a factor of 2.4. Furthermore, the extended improved model is used to predict the half-lives of some possible proton radioactivity candidates in NUBASE2020 that are energetically allowed or have been observed but not yet quantified. This work improves the accuracy of proton radioactivity studies and provides a robust theoretical framework for future nuclear structure research.

2605.29248 2026-06-11 physics.ao-ph 版本更新

Steering Tropical Cyclones Using Small Perturbations in an AI Weather Model

在AI天气模型中使用小扰动引导热带气旋

Qin Huang, Moyan Liu, Yeongbin Kwon, Upmanu Lall

AI总结 本研究在AI天气模型中结合有限时间李雅普诺夫指数(FTLE)诊断与理想化热力学扰动,通过引导扰动位置显著改变热带气旋路径,发现FTLE引导的扰动比随机扰动产生更大的轨迹偏移,且敏感性集中在再弯曲区域。

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AI中文摘要

热带气旋(TC)轨迹受大尺度引导流控制,对初始条件敏感,引发了一个问题:有针对性的扰动是否能引起轨迹偏差。我们在“天气柔术”框架内进行了一项案例研究,该框架利用关键时刻的动态敏感性来影响极端事件,通过将有限时间李雅普诺夫指数(FTLE)诊断与AI天气预报模型中的理想化热力学扰动相结合。应用于2012年飓风桑迪登陆前六天,引导环境中的FTLE引导扰动产生了322.9公里的轨迹位移,是同等播种能量随机扰动(平均97.6公里)的3.3倍。桑迪深加勒比海引导环境中的FTLE引导位点在前五天预报期间产生了36-50公里的持续位置偏移,当桑迪在第五天重新弯曲进入中纬度斜压区时,该偏移被放大。三个控制实验——随机放置(97.6公里)、向后FTLE针对副热带高压(91.5公里)以及向前FTLE在TC暖心内700 hPa计算(55.0公里)——表明,较大的响应与使用向前FTLE指导针对500 hPa环境引导流边界有关。一个补充实验在桑迪再弯曲前1天于北太平洋应用FTLE引导扰动,产生了616.6公里,几乎是加勒比海结果的两倍,表明轨迹敏感性集中在再弯曲门附近,而不是跨越7天预报窗口。所需的扰动幅度超出了当前的工程能力,因此结果代表了理论敏感性分析。这些发现表明,FTLE诊断可能有助于识别与增强的下游轨迹敏感性相关的引导流边界。

英文摘要

Tropical cyclone (TC) trajectories are governed by large-scale steering flows and exhibit sensitive dependence on atmospheric initial conditions. Using Hurricane Sandy (2012) in the Aurora AI weather model, we investigate whether targeted thermodynamic perturbations can induce meaningful track deviations. Two distinct perturbation regimes emerge. In the Caribbean, forward finite-time Lyapunov exponent (FTLE) diagnostics identify dynamically sensitive regions within Sandy's steering flow, where perturbations produce substantially larger responses than random placement. In the Pacific, a preferred corridor near 165W influences Sandy through Rossby wave teleconnections, confirmed using Takaya-Nakamura wave activity flux diagnostics. Despite their different physical pathways, both regimes share a common amplification mechanism: small initial perturbations generate modest trajectory offsets that are rapidly amplified when Sandy enters the highly sensitive recurvature region. The largest experiments produce track deviations exceeding 500 km after seven days. These results provide a proof-of-concept demonstration of the Weather Jiu-Jitsu framework, illustrating how targeted perturbations can be amplified through atmospheric dynamics in an AI weather model. Because the required perturbations exceed current operational cloud-seeding capabilities, the experiments should be interpreted as a theoretical sensitivity analysis rather than an operational weather modification strategy.