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2604.18179 2026-05-27 cs.CR cs.AI

Committed SAE-Feature Traces for Audited-Session Substitution Detection in Hosted LLMs

托管LLM中审计会话替换检测的承诺SAE特征轨迹

Ziyang Liu

AI总结 提出一种承诺-开放协议,通过Merkle树提交稀疏自编码器特征轨迹,以检测托管LLM提供商在服务中静默替换模型的行为。

Comments We identified inaccuracies in the security analysis: the closed-form intrinsic-dimension lower bound on the feature-forgery attacker (Proposition 4.2, Section 4, Appendix V) and the cross-backend noise calibration for the joint z-score threshold (Section 5.1, Table 2). These affect the claimed attack-resistance guarantees. We are withdrawing the paper to correct them before resubmission

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AI中文摘要

托管LLM提供商存在静默替换的动机:宣传更强的模型,同时提供更便宜的回复。诸如SVIP的探测后返回方案存在并行服务的侧信道,因为不诚实的提供商可以将验证者的探测路由到广告模型,同时为普通用户提供替代模型。我们提出一种承诺-开放协议来弥补这一漏洞。在任何开放请求之前,提供商通过Merkle树提交其在发布探测层上服务输出的每个位置稀疏自编码器(SAE)特征轨迹草图。验证者打开随机位置,根据公共命名电路探测库(经过跨后端噪声校准)进行评分,并使用固定阈值联合一致性z分数规则做出决策。我们在三个骨干模型上实例化该协议——Qwen3-1.7B、Gemma-2-2B,以及扩展到Gemma-2-9B(配备131k特征SAE)的4.5倍规模。在17种攻击者中,包括同族提升、跨族替代和秩<=128的自适应LoRA,所有攻击者都在共享的尺度稳定阈值下被拒绝;相同的攻击者都规避了匹配的SVIP风格并行服务基线。一种通过冻结SAE编码器反向传播的白盒端到端攻击并未缩小差距,而一种从不运行M_hon的特征伪造攻击者通过内在维度论证被封闭形式地限制。承诺在批大小为32时,仅增加不超过2.1%的前向计算时间。

英文摘要

Hosted-LLM providers have a silent-substitution incentive: advertise a stronger model while serving cheaper replies. Probe-after-return schemes such as SVIP leave a parallel-serve side-channel, since a dishonest provider can route the verifier's probe to the advertised model while serving ordinary users from a substitute. We propose a commit-open protocol that closes this gap. Before any opening request, the provider commits via a Merkle tree to a per-position sparse-autoencoder (SAE) feature-trace sketch of its served output at a published probe layer. A verifier opens random positions, scores them against a public named-circuit probe library calibrated with cross-backend noise, and decides with a fixed-threshold joint-consistency z-score rule. We instantiate the protocol on three backbones -- Qwen3-1.7B, Gemma-2-2B, and a 4.5x scale-up to Gemma-2-9B with a 131k-feature SAE. Of 17 attackers spanning same-family lifts, cross-family substitutes, and rank-<=128 adaptive LoRA, all are rejected at a shared, scale-stable threshold; the same attackers all evade a matched SVIP-style parallel-serve baseline. A white-box end-to-end attack that backpropagates through the frozen SAE encoder does not close the margin, and a feature-forgery attacker that never runs M_hon is bounded in closed form by an intrinsic-dimension argument. Commitment adds <=2.1% to forward-only wall-clock at batch 32.

2504.19203 2026-05-27 eess.IV cs.CV

Improving Generalization in MRI-Based Deep Learning Models for Total Knee Replacement Prediction

基于MRI的深度学习模型在全膝关节置换预测中的泛化能力改进

Ehsan Karami, Hamid Soltanian-Zadeh

AI总结 针对MRI深度学习模型在不同来源数据上泛化性差的问题,提出用实例归一化替代批归一化、数据增强和对比损失的方法,在OAI数据集上显著提升分类性能。

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Journal ref
Proceedings of the 2025 32nd National and 10th International Iranian Conference on Biomedical Engineering (ICBME)
AI中文摘要

膝骨关节炎(KOA)是一种常见的关节疾病,会导致疼痛和行动不便。尽管基于MRI的深度学习模型在全膝关节置换(TKR)和疾病进展预测中表现出优越性能,但其泛化能力仍然具有挑战性,尤其是在应用于不同来源的影像数据时。在本研究中,我们证明用实例归一化替代批归一化、使用数据增强以及应用对比损失可以改善泛化能力。在训练和评估中,我们使用了来自骨关节炎倡议(OAI)数据库的MRI数据,将矢状面脂肪抑制中间加权涡轮自旋回波(FS-IW-TSE)图像作为源域,矢状面脂肪抑制三维(3D)双回波稳态(DESS)图像作为目标域。结果表明,通过在基线模型中将批归一化替换为实例归一化,使用全局强度非线性(GIN)增强方法生成增强输入视图,以及在分类损失之外加入监督对比损失以对齐相同标签样本的表征,两个域的分类指标均有统计学显著提升。当使用3D实例归一化时,带有对比损失的GIN方法优于所有评估的单源域泛化方法。比较有无对比损失的GIN(针对两种归一化类型)表明,添加对比损失始终带来更好的性能。

英文摘要

Knee osteoarthritis (KOA) is a common joint disease that causes pain and mobility issues. While MRI-based deep learning models have demonstrated superior performance in predicting total knee replacement (TKR) and disease progression, their generalizability remains challenging, particularly when applied to imaging data from different sources. In this study, we show that replacing batch normalization with instance normalization, using data augmentation, and applying contrastive loss improves generalization. For training and evaluation, we used MRI data from the Osteoarthritis Initiative (OAI) database, considering sagittal fat-suppressed intermediate-weighted turbo spin-echo (FS-IW-TSE) images as the source domain and sagittal fat-suppressed three-dimensional (3D) dual-echo in steady state (DESS) images as the target domain. The results demonstrated a statistically significant improvement in classification metrics across both domains by replacing batch normalization with instance normalization in the baseline model, generating augmented input views using the Global Intensity Non-linear (GIN) augmentation method, and incorporating a supervised contrastive loss alongside the classification loss to align representations of samples with the same label. The GIN method with contrastive loss performed better than all evaluated single-source domain generalization methods when using 3D instance normalization. Comparing GIN with and without contrastive loss (for both normalization types) showed that adding contrastive loss consistently led to better performance.

2605.27270 2026-05-27 stat.AP stat.ML

Inverse Control Constrained Optimization of Vessel Speed Decisions Under Environmental Risk: Evidence from Arctic Shipping

环境风险下船舶速度决策的逆控制约束优化:来自北极航运的证据

Mauli Pant, Linda Fernandez, Indranil Sahoo

AI总结 通过逆控制约束优化框架,利用超过1400万条AIS观测数据估计船舶速度决策中的风险参数,揭示了不同船型和航行状态在运营效率、冰风险与鲸鱼生态风险之间的权衡模式。

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AI中文摘要

理解决策者如何在运营效率与环境生态风险之间进行权衡是船舶航行的核心问题。我们将船舶速度建模为约束优化框架中的控制变量,其中船舶运营商平衡多个相互竞争的目标,包括运输效率、与冰相关的航行风险以及与鲸鱼相关的生态风险。底层风险参数使用来自美国北极地区(2010-2019年)的超过1400万条自动识别系统(AIS)观测数据,结合环境协变量和空间明确的鲸鱼密度估计进行估计。该框架包含非线性风险目标、船舶异质性和正则化,以确保结果稳定且可解释。推断出的权衡揭示了不同船组和航行状态下的不同决策模式。拖船和货船等船型在运营速度与环境生态考量之间取得平衡。相比之下,包括渔船、客船和未指定船舶在内的几个船组受到冰相关风险的强烈影响,而游艇和油轮则对鲸鱼相关风险表现出更高的敏感性。在不同航行状态类别中,也观察到类似的异质性。主导状态“使用发动机航行”显示出清晰的权衡,而其他状态,如“搁浅”和“未定义”,则受到冰相关约束的强烈影响。包括“操纵能力受限”和“从事捕鱼”在内的状态对鲸鱼相关风险表现出更高的估计敏感性,尽管存在较大的不确定性。敏感性分析表明,增加鲸鱼相关风险权重对模型隐含的最优速度产生有限的变化,而增加冰相关风险则导致更一致的减速。

英文摘要

Understanding how decision makers balance operational efficiency with environmental and ecological risks is central to vessel navigation. We model vessel speed as a control variable in a constrained optimization framework in which vessel operators balance multiple competing objectives, including transit efficiency, ice related navigational risk, and whale related ecological risk. The underlying risk parameters are estimated using over 14 million Automatic Identification System (AIS) observations from the United States Arctic (2010-2019), together with environmental covariates and spatially explicit whale density estimates. The framework incorporates a nonlinear risk objective, vessel heterogeneity, and regularization to ensure stable and interpretable results. The inferred trade offs reveal distinct decision making patterns across vessel groups and navigational statuses. Vessel types such as Tug Tow and Cargo balance operational speed with environmental and ecological considerations. In contrast, several vessel groups, including Fishing, Passenger, and Unspecified vessels, are strongly influenced by ice related risk, while Pleasure Craft and Tankers exhibit higher sensitivity to whale related risk. Across navigational status categories, similar heterogeneity is observed. The dominant status, under way using engine, displays a clear trade off, whereas other statuses, such as aground and undefined, are strongly shaped by ice related constraints. Statuses including restricted maneuverability and engaged in fishing exhibit higher estimated sensitivity to whale related risk, though with substantial uncertainty. Sensitivity analysis indicates that increasing whale-related risk weighting produces limited changes in model-implied optimal speed, whereas increasing ice-related risk leads to more consistent reductions.

2605.25938 2026-05-27 cond-mat.supr-con

Exact Single-Scale Outer Solution of the Abrikosov Vortex in the Extreme Type-II Limit

极端第二类极限下阿布里科索夫涡旋的精确单尺度外解

Eugene B. Kolomeisky

AI总结 在Ginzburg-Landau参数κ发散时,通过求解超流速度的非线性理论,得到了极端第二类极限下阿布里科索夫涡旋的精确外结构,证明磁场和超导密度均在伦敦穿透深度尺度上变化,推翻了传统的双尺度图像。

Comments 4 pages, 2 figures

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AI中文摘要

我们确定了极端第二类极限下阿布里科索夫涡旋的精确外结构,该极限发生在Ginzburg-Landau参数$κ$发散时。在此极限下,Ginzburg-Landau理论在缩小的核心外部简化为一个封闭的非线性理论,描述超流速度并受代数密度约束。所得解在消失的涡旋核心外部处处渐近精确,证明磁场和超导密度均在伦敦穿透深度的长度尺度上变化。这确立了传统的涡旋双尺度图像在$κ\gg 1$极限下不成立。

英文摘要

We determine the exact outer structure of the Abrikosov vortex in the extreme type-II limit, which occurs when the Ginzburg-Landau parameter $κ$ diverges. In this limit, Ginzburg-Landau theory simplifies, outside a shrinking core, to a closed nonlinear theory for the superfluid velocity subject to an algebraic density constraint. The resulting solution is asymptotically exact everywhere outside the vanishing vortex core, demonstrating that both magnetic field and superconducting density vary on the length scale of the London penetration depth. This establishes that the conventional two-length-scale picture of the vortex does not hold in the $κ\gg 1$ limit.

2605.04645 2026-05-27 astro-ph.GA astro-ph.CO

The MeerKAT Massive Distant Clusters Survey: a search for diffuse radio emission in 30 massive SZ-selected clusters at $z > 1$

MeerKAT大质量遥远星系团巡天:在30个$z>1$的大质量SZ选星系团中搜寻弥漫射电辐射

Dakalo G. Phuravhathu, M. Hilton, S. P. Sikhosana, D. Y. Klutse, K. Knowles, J. van Marrewijk, K. Moodley, T. Mroczkowski, N. Oozeer, B. Partridge, Y. C. Perrott, C. Sifón, U. Sureshkumar

AI总结 利用MeerKAT 1.28 GHz观测,在30个红移$z>1$的大质量SZ选星系团中搜寻弥漫射电辐射,发现8个射电晕(27%),并分析了射电功率与团块质量的标度关系,揭示了高红移下射电晕的探测率低于中等红移但仍高于理论预期。

Comments 23 pages, 15 figures, 4 tables. Accepted for publication in MNRAS

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Journal ref
Mon Not R Astron Soc (2026)
AI中文摘要

我们展示了对一个均匀选择的30个红移$z>1$的最大质量Sunyaev-Zel'dovich选星系团样本中弥漫射电辐射的搜寻结果,首次提供了该红移以上团尺度弥漫射电辐射演化的统计约束。我们还分析了该高红移样本中射电功率($P_{1.4\,\mathrm{GHz}}$)与团块质量($M_{\rm 500c}$)之间的标度关系。已知射电晕主要存在于最大质量的星系团中,在那里主要并合产生的湍流能量可以重新加速相对论性电子并在兆秒差距尺度上放大磁场。深度的MeerKAT 1.28 GHz观测在8个星系团(27%)中揭示了弥漫射电晕,而其余21个(70%)未显示任何发射;另外1个星系团(3%)因数据质量差被排除在射电分析之外。该高红移样本中的射电晕探测率低于中等红移,但仍高于理论模型在$z \gtrsim 1$时普遍预测的$\lesssim 10\%$的出现率。探测到的射电晕围绕MMDCS样本的最佳拟合$P_{1.4\,\mathrm{GHz}}$-$M_{\rm 500c}^{\rm {Unc}}$关系散布,而非探测样本则占据射电功率-质量平面的下包络,与低红移观测到的趋势相似。未识别出团尺度的射电遗迹或迷你晕。我们的发现突显了MeerKAT探测最遥远星系团中非热过程的能力,以及需要更深的低频巡天来揭示微弱的弥漫发射并检验$P_{1.4\,\mathrm{GHz}}$-$M_{\rm 500}$关系在宇宙时间上的持续性。

英文摘要

We present the results of a search for diffuse radio emission in a uniformly selected sample of 30 of the most massive Sunyaev-Zel'dovich selected galaxy clusters at $z > 1$, providing the first statistical constraints on the evolution of cluster-scale diffuse emission beyond this redshift. We also analyse the scaling relations between radio power ($P_{1.4\,\mathrm{GHz}}$) and cluster mass ($M_{\rm 500c}$) in this high-redshift sample. It is well established that radio halos are primarily found in the most massive clusters, where turbulent energy from major mergers can re-accelerate relativistic electrons and amplify magnetic fields on megaparsec scales. Deep MeerKAT 1.28 GHz observations reveal diffuse radio halos in eight clusters (27$\%$), while the remaining 21 (70$\%$) show no emission; one additional cluster (3$\%$) was excluded from the radio analysis due to poor data quality. The halo detection rate in this high-redshift sample is lower than at intermediate redshift, but remains higher than the $\lesssim 10\%$ occurrence generally predicted by theoretical models at $z \gtrsim 1$. The detected radio halos scatter around the best-fitting $P_{1.4\,\mathrm{GHz}}$-$M_{\rm 500c}^{\rm {Unc}}$ relation derived for the MMDCS sample, whereas non-detections populate the lower envelope of the radio power-mass plane, similar to trends seen at lower redshift. No cluster-scale radio relics or mini-halos are identified. Our findings highlight MeerKAT's ability to probe non-thermal processes in the most distant clusters and the need for deeper, lower-frequency surveys to uncover faint diffuse emission and test the persistence of the $P_{1.4\,\mathrm{GHz}}$-$M_{\rm 500}$ relation across cosmic time.

2605.27370 2026-05-27 astro-ph.GA

First Light and Reionization Epoch Simulations (FLARES) XXII: UV-dust spatial offsets at the Epoch of Reionisation

第一光与再电离纪元模拟 (FLARES) XXII:再电离纪元的紫外-尘埃空间偏移

Paurush Punyasheel, Aswin P. Vijayan, William J. Roper, Thomas R. Greve, Hiddo Algera, Christopher C. Lovell, Steven Gillman, Bitten Gullberg, Shihong Liao, Robert M. Yates, Stephen M. Wilkins

AI总结 利用FLARES模拟和辐射传输代码,统计了高红移星系中紫外与远红外发射峰的空间偏移,发现约16%的星系存在≥2.5 kpc的偏移,且偏移与恒星质量、光度等无关,而与更蓝的紫外斜率、早期恒星形成历史及金属丰度相关。

Comments Submitted to MNRAS. 11 pages

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AI中文摘要

最近的观测揭示了高红移星系中紫外(UV)和远红外(FIR)发射之间有趣的偏移。在本研究中,我们使用第一光与再电离纪元模拟(\textsc{Flares})计算了一个统计样本(6890个)中大质量(M$_{\\star}\\, \\gtrsim10^{9} \\,{\rm M_{\\odot}}$)高红移星系($z \\in [5,10]$)的紫外和远红外中心的空间偏移。这些星系经过\textsc{skirt}辐射传输代码的后处理,以获得完整的光谱能量分布和表面亮度分布。我们模拟了\textit{詹姆斯·韦伯空间望远镜(JWST)}近红外相机(NIRCam;静止帧1500 Å,分辨率约$0.031''$)和ALMA静止帧158 \um(角分辨率约$0.3''$)的观测,然后计算UV-FIR中心之间的距离,以分析驱动观测到的UV-FIR空间偏移的物理过程。我们发现约16.23%的星系在其UV和FIR发射峰值之间表现出$\\geq 2.5$ kpc的空间偏移。我们确定空间偏移与恒星质量、UV/FIR光度以及大小无关。偏移也与活动星系核反馈、大尺度环境或并合历史无关。具有显著偏移的星系优先表现出更蓝的紫外斜率($-2.5<β<-1.5$),这与最近的恒星形成和尘埃衰减的核心导致观测到的UV质心位移一致。它们显示出加速的恒星形成历史,比没有偏移的星系早约0.1 Gyr形成其$z=5$恒星质量的一半。这些星系比没有偏移的星系更早富集,并显示出增强的恒星金属丰度,表明在更高红移($z \\geq 6$)时向外生长的转变。

英文摘要

Recent observations have revealed intriguing offsets between the UV and FIR emission in high redshift galaxies. In this study, we use the First Light And Reionisation Epoch Simulations (\textsc{Flares}) to compute the spatial offset of ultraviolet (UV) and far-infrared (FIR) centres for a statistical sample (6890) of massive (M$_{\star}\, \gtrsim10^{9} \,{\rm M_{\odot}}$) high redshift galaxies ($z \in [5,10]$). The galaxies are post-processed with the \textsc{skirt} radiative transfer code, to obtain the full spectral energy distribution and surface brightness profile. We simulate \textit{James Webb Space Telescope (JWST)} Near Infrared Camera (NIRCam; rest-frame 1500 Å, $ \approx 0.031 ''$ resolution) and ALMA rest-frame 158 \um\ ($\approx$ $0.3''$ angular resolution) observations of the galaxies and then calculate the distance between the UV-FIR centres to analyse which physical processes drive the observed UV - FIR spatial offset. We find that $\sim16.23\%$ of galaxies exhibit spatial offsets of $\geq 2.5$ kpc between their UV and FIR emission peaks. We establish that the spatial offsets do not correlate with stellar mass, UV/FIR luminosity, and size. Offsets also do not correlate with AGN feedback or with large-scale environment or merger history. Galaxies with significant offsets preferentially have bluer UV slopes ($-2.5<β<-1.5$), consistent with recent star formation and dust-attenuated cores displacing the observed UV centroid. They show an accelerated star formation history, forming half their $z=5$ stellar mass $\sim$0.1 Gyr earlier than galaxies without offsets. These galaxies are enriched earlier than galaxies without an offset and show enhanced stellar metallicities, indicating a transition to an outward growth at higher redshifts ($z \geq 6$).

2605.27369 2026-05-27 quant-ph

Generalized multilevel amplitude damping channels and their thermodynamic performances

广义多级振幅阻尼通道及其热力学性能

Vito Vetrano, Vittorio Giovannetti, Vasco Cavina

AI总结 本文引入广义多级振幅阻尼(GMAD)通道来模拟与热环境耦合的qudit中的噪声和退相干效应,通过评估功泛函和ergotropic电容研究GMAD下能量资源的退化,揭示了ergotropic电容随环境温度非单调变化以及马尔可夫Mpemba效应等反直觉现象。

Comments 7 pages + 10 pages of appendices, 4 figures

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AI中文摘要

我们引入了一类新的量子通道,即广义多级振幅阻尼(GMAD)通道,用于模拟与热环境耦合的qudit中的噪声和退相干效应。通过评估功泛函和ergotropic电容,研究了GMAD下能量资源的退化,特别关注ergotropy的相干和非相干贡献,为此我们引入了新的量化指标。我们的分析揭示了如何在热环境中最优地制备qudit以从功提取的角度保留其价值,并揭示了几个反直觉的现象:GMAD通道的ergotropic电容随环境温度非单调变化;此外,迭代该映射可能导致不同温度下ergotropic泛函的交叉,表明存在马尔可夫Mpemba效应。

英文摘要

We introduce a new class of quantum channels, the Generalized Multilevel Amplitude Damping (GMAD) channels, to model noise and decoherence effects in a qudit coupled to a thermal environment. The degradation of energetic resources under GMADs is investigated by evaluating work functionals and ergotropic capacitances, with particular attention to the coherent and incoherent contributions to ergotropy, for which we introduce new quantifiers. Our analysis sheds light on how to optimally prepare a qudit in a thermal environment in order to preserve its value from the perspective of work extraction, and reveals several counterintuitive phenomena: the ergotropic capacitance of a GMAD channel is not monotonic in the temperature of the environment; moreover, iterating the map can lead to crossings between ergotropic functionals at different temperatures, indicating the presence of a Markovian Mpemba effect.

2605.27368 2026-05-27 cond-mat.mes-hall

Spontaneous persistent currents and time-reversal symmetry breaking in thick-walled Weyl semimetal cylinders

厚壁外尔半金属圆柱体中的自发持续电流和时间反演对称性破缺

J. C. Pérez-Pedraza, Juan A. Cañas, Daniel A. Bonilla, A. Martín-Ruiz

AI总结 通过低能有效哈密顿量解析求解厚壁外尔半金属圆柱体的本征值问题,发现外尔节点的空间分离作为内禀手征规范场,在零外磁通下自发破缺时间反演对称性,产生持续电流和电导通道展开。

Comments 16 pages, 13 figures

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AI中文摘要

我们理论研究了在外部轴向磁场作用下的厚壁外尔半金属(WSM)圆柱体中的阿哈罗诺夫-玻姆效应。通过采用低能有效哈密顿量,我们解析求解了无限长和有限长圆柱几何的本征值问题。在径向壁处应用无限质量边界条件,在圆柱帽处应用MIT袋边界条件,以分别正确考虑节点内约束和谷间散射。我们的数值结果表明,外尔节点的空间分离充当了内禀手征规范场。这个几何场内禀地破缺了时间反演(TR)对称性,即使在零外磁通下也解除了手征简并。这种对称性破缺表现为自发持续电流和电导通道的展开。此外,纵向约束诱导了传播方向依赖的能量分裂,改变了部分态密度并导致空间-手征电流不平衡。

英文摘要

We theoretically investigate the Aharonov-Bohm effect in a thick-walled Weyl semimetal (WSM) cylinder subject to an external axial magnetic field. By employing a low-energy effective Hamiltonian, we analytically solve the eigenvalue problem for both infinite and finite-length cylindrical geometries. We apply infinite-mass boundary conditions at the radial walls and MIT bag boundary conditions at the cylinder caps to properly account for intra-node confinement and inter-valley scattering, respectively. Our numerical results demonstrate that the spatial separation of the Weyl nodes acts as an internal chiral gauge field. This geometric field intrinsically breaks time-reversal (TR) symmetry, lifting the chiral degeneracy even at zero external flux. This symmetry breaking manifests as spontaneous persistent currents and the unfolding of conductance channels. Furthermore, longitudinal confinement induces propagation-direction-dependent energy splitting, altering the partial density of states and causing spatio-chiral current imbalances.

2605.27364 2026-05-27 astro-ph.SR astro-ph.EP astro-ph.GA astro-ph.IM

A Minute-Cadence Deep Bulge Survey: First Data Release of DREAMS

分钟级深度银心巡天:DREAMS首次数据发布

Hongjing Yang, Weicheng Zang, Francisco Valdes, Qiyue Qian, Yuchen Tang, Zhixing Li, Yuxin Shang, Shude Mao, Yaosong Yu, Guillermo Damke, Alfredo Zenteno, Steve Heathcote, Konstantina Boutsia, Andong Xu, Hao Ma, Jiyuan Zhang, Hongyu Li, Xikai Shan, Przemek Mróz, Xiurui Zhao, Andrew Gould, Jennifer C. Yee, Chung-Uk Lee, Matthew Penny, Sean Terry, Patrick Tamburo, Tim Cunningham, Quanzhi Ye, Eric W. Peng, Rachel Street, Katarzyna Kruszyńska, Etienne Bachelet, Yiannis Tsapras, Markus Hundertmark

AI总结 基于DECam的DREAMS巡天项目在银心5平方度区域进行三年分钟级测光观测,首次数据发布包含约5900万颗恒星的z波段和r波段光变曲线,用于探测低质量自由漂浮行星、恒星耀发和短时标变星。

Comments 18 pages, 11 figures, 2 tables. Data release portal: https://astro.westlake.edu.cn/dreams

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AI中文摘要

DECam流浪地球与火星巡天(DREAMS)是NOIRLab的一个巡天项目,自2025年6月起在银心5平方度区域进行为期三年的巡天。其主要科学目标是通过微引力透镜探测低质量自由漂浮行星,同时其分钟级采样率还能探测和表征时标从分钟到小时的快速现象,如恒星耀发和脉动变星。本文介绍了2025年DREAMS观测数据的处理和校准,并发布了首次DREAMS数据(DR1)。DR1包含59,372,789颗恒星的1,856次z波段观测和325次r波段观测。DREAMS DR1星表包含的恒星数量至少是覆盖相同5平方度区域的其他星表的两倍。我们展示了已知蓝大振幅脉动变星和已知凌星系系统的DREAMS光变曲线,以展示巡天的能力。我们还对DR1样本中约0.4%的区域进行了短时标变星的试搜索,识别出一个新的短时标微引力透镜事件、两个恒星耀发和24个新的短时标变星。这表明DREAMS DR1可能包含数百个恒星耀发和数千个此前未知的短时标变星。

英文摘要

The DECam Rogue Earths and Mars Survey (DREAMS), a NOIRLab survey program, has been conducting a three-year survey covering a 5\,deg$^2$ area in the Galactic bulge since 2025 June. Its primary science goal is to detect low-mass free-floating planets through microlensing, while its minute-level cadence also enables the detection and characterization of rapid phenomena on timescales of minutes to hours such as stellar flares and pulsating stars. Here, we present the data reduction and calibration of the DREAMS observations obtained in 2025 and introduce the first DREAMS data release (DR1). DR1 includes 1,856 $z$-band observations and 325 $r$-band observations for 59,372,789 stars. The DREAMS DR1 catalog contains at least twice as many stars as any previous catalog covering the same 5\,deg$^2$ area. We present DREAMS light curves for a known blue large-amplitude pulsator and a known transiting system to demonstrate the survey's capabilities. We also perform a pilot search for short-duration variables over about 0.4% of the DR1 sample, identifying one new short microlensing event, two stellar flares, and 24 new short variables. This suggests that DREAMS DR1 may contain hundreds of stellar flares and thousands of previously unknown short variables.

2605.27363 2026-05-27 astro-ph.GA

The first near-infrared high-resolution échelle spectroscopy of the outflow in NGC 4151. A study of the clouds covering the Eye of Sauron

NGC 4151外流首次近红外高分辨率阶梯光谱:覆盖索伦之眼的云团研究

Francesco Gabriele Saturni, Riccardo Middei, Hermine Landt, Valerio D'Elia, Fabio La Franca, Matteo Perri, Enrico Piconcelli

AI总结 利用IRTF/iSHELL和TNG/GIANO-B光谱仪对NGC 4151(“索伦之眼”)进行首次近红外高分辨率光谱观测,结合Swift-XRT数据,揭示He I吸收线变化与X射线电离连续谱变化相关,并限制外流物理参数。

Comments 12 pages, 7 figures, 3 tables, accepted for publication on Astronomy & Astrophysics

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AI中文摘要

我们展示了附近著名的赛弗特星系NGC 4151(“索伦之眼”)核区的首次高分辨率近红外光谱。过去对该源的研究揭示了一个与He I λ10,830 Å发射线相关的可变吸收特征,可能指示影响中央引擎的遮蔽事件。这里,我们利用IRTF/iSHELL和TNG/GIANO-B光谱仪以空前的光谱分辨率(λ/Δλ > 50,000)观测该特征,能够详细研究吸收槽的结构及其在约700天时间跨度内的变化。为了推断He I吸收变化与X射线电离连续谱变化之间的联系,我们还分析了同一时期由Swift-XRT仪器收集的公开数据,揭示了由于X射线通量变化导致的外流电离态变化的潜在驱动机制。我们还推导了外流物理参数——Ṁ_out ≲ 10^{-2} M_⊙ yr^{-1},r_out ~ 3 pc,v_max ~ 1000 km s^{-1}——这些参数与类似目标中发现的相当的电离风一致,其中外流不足以触发显著的AGN反馈(Ė_kin/L_bol ~ 0.001%)。这些发现指向一个场景:一个遮蔽NGC 4151直至星系尺度的尘埃和团块外流响应电离X射线通量的变化,类似于具有宽吸收线的类星体和具有多相外流的赛弗特星系(如NGC 5548)中发生的情况。

英文摘要

We present the first high-resolution near-infrared spectroscopy of the nucleus of the nearby, well-known Seyfert galaxy NGC 4151 (the "Eye of Sauron"). Past studies of this source have revealed that it exhibits a variable absorption feature associated with the He I $λ$10,830 AA emission line, potentially indicative of obscuration events affecting the central engine. Here, we take advantage of the IRTF/iSHELL and TNG/GIANO-B spectrographs to observe this feature with unprecedented spectral resolution ($λ/Δλ> 50,000$), being able to study in detail the structure of the absorption trough and its variations over a time span of $\sim$700 days. In order to infer a connection between the He I absorption variability and that of the X-ray ionising continuum, we also analyse the publicly available data collected by the Swift-XRT instrument over the same period of time, unveiling a potential driving mechanism in the changes of the outflow ionisation state due to the X-ray flux variations. We also derive outflow physical parameters - $\dot{M}_{\rm out} \lesssim 10^{-2}$ M$_\odot$ yr$^{-1}$, $r_{\rm out} \sim 3$ pc, $v_{\rm max} \sim 1000$ km s$^{-1}$ - that are in line with those of comparable ionised winds found in similar targets, where the outflow is not powerful enough to trigger a significant AGN feedback ($\dot{E}_{\rm kin}/L_{\rm bol} \sim 0.001$%). Such findings point at a scenario in which a dusty and clumpy outflow that obscures NGC 4151 up to galactic scales responds to changes in the ionising X-ray flux, similarly to what happens in quasars with broad absorption lines and Seyferts with multiphase outflows such as NGC 5548.

2605.27362 2026-05-27 astro-ph.EP

Hot Jupiters' Isolation Is Not Unique to High-Eccentricity Tidal Migration

热木星的孤立并非高偏心率潮汐迁移所独有

Brandon Radzom, Songhu Wang, Bonan Pu, Hareesh Gautham Bhaskar, Malena Rice

AI总结 通过数值模拟表明,热木星在形成后与伴星的动力学演化自然导致其比暖木星更孤立,无需依赖高偏心率潮汐迁移。

Comments 24 pages, 8 figures, 2 tables. Submitted to AAS journals

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AI中文摘要

传统上,观测到的热木星孤立性——即附近缺乏低质量行星伴星——被视为这些近距离气态巨行星经历高偏心率潮汐迁移的证据。这种孤独与暖木星常见的紧凑构型形成鲜明对比,暗示这两类短周期巨行星在动力学起源上存在奇特二分性。然而,在本研究中,我们对两类巨行星采用统一的宁静形成框架,即它们从原行星盘中作为紧凑多超级地球系统中的唯一木星行星出现。我们使用长期数值模拟表明,盘后动力学演化自然会导致热木星相对于暖木星在观测上更倾向于孤立。具体而言,它们的伴星实现了显著更大的周期比和相互倾角,使其更难被探测——尤其是通过凌星法。此外,我们发现这一范式与长周期热木星拥有共面轨道内部伴星的谜样群体一致。该模型的另一个预测——最好通过高精度多普勒巡天检验——是热木星存在一群近距离(周期<50天)但相互倾斜的外部伴星。

英文摘要

Conventionally, the observed isolation of hot Jupiters, marked by a paucity of nearby low-mass planetary companions, has been interpreted as evidence of high-eccentricity tidal migration for these close-in gas giants. This loneliness is in stark contrast with the compact configurations commonly observed for warm Jupiters, indicating a curious dichotomy in dynamical origins between these two classes of short-period giants. In this study, however, we adopt a unified quiescent framework for both giant populations wherein they emerge from the protoplanetary disk as the sole Jovian planet within a compact multi-super-Earth system. We use long-term numerical simulations to show that post-disk dynamical evolution will naturally result in an observed preferential isolation for hot Jupiters relative to warm Jupiters. Specifically, their companions achieve significantly larger period ratios and mutual inclinations, rendering them more difficult to detect - especially via the transit method. Additionally, we find that this paradigm is consistent with the enigmatic population of longer-period hot Jupiters hosting interior companions on coplanar orbits. Another prediction of this model, best tested through high-precision Doppler campaigns, is the existence of a population of close-in (P<50 days) but mutually inclined outer companions to hot Jupiters.

2605.27359 2026-05-27 hep-th

Wilson coefficients from a non-renormalization theorem in 2D SYM

二维超对称杨-米尔斯理论中的非重整化定理与Wilson系数

Kabir Bajaj

AI总结 利用紫外规范理论中的非重整化论证,确定了矩阵弦理论中对称积轨形CFT的Dijkgraaf-Verlinde-Verlinde算符的Wilson系数,结果与矩阵弦理论猜想一致。

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AI中文摘要

矩阵弦理论(arXiv:hep-th/9703030, arXiv:hep-th/9701025, arXiv:hep-th/9710009)是二维最大超对称$U(N)$杨-米尔斯理论与十维闵可夫斯基时空中的IIA型弦理论之间的猜想对偶。该规范理论的红外描述由对称积轨形$(\mathbb{R}^8)^N/S_N$ CFT主导。来自该红外不动点的最相关不可忽略形变是Dijkgraaf-Verlinde-Verlinde算符,它带有一个未知的Wilson系数。我们利用紫外规范理论中的非重整化论证确定了该系数。结果与矩阵弦理论猜想一致,并为$g_{\rm YM}$与弦耦合之间的关系提供了第一性原理检验。我们还评论了用类似方法确定其他Wilson系数的前景。

英文摘要

Matrix string theory (arXiv:hep-th/9703030, arXiv:hep-th/9701025, arXiv:hep-th/9710009) is a conjectured duality between two-dimensional maximally supersymmetric $U(N)$ Yang-Mills theory and type-IIA string theory in ten-dimensional Minkowski spacetime. The IR description of this gauge theory is governed by the symmetric product orbifold $(\mathbb{R}^8)^N/S_N$ CFT. The leading irrelevant deformation from this IR fixed point is the Dijkgraaf-Verlinde-Verlinde operator, which comes with an unknown Wilson coefficient. We determine this coefficient using non-renormalization arguments from the UV gauge theory. The result is consistent with the matrix string theory conjecture and gives a first-principles check of the relation between $g_{\rm YM}$ and the string coupling. We also comment on the prospects for fixing further Wilson coefficients using similar methods.

2605.27357 2026-05-27 astro-ph.CO gr-qc hep-ph hep-th

Gaussian Process Reconstruction of Cosmological Parameters with Gravitational Wave Sirens using Machine Learning

利用机器学习与引力波标准汽笛对宇宙学参数的高斯过程重建

Gourab Nandi, Anish Ghoshal, David F. Mota

AI总结 本文提出基于高斯过程回归的模型无关框架,通过分析LISA和爱因斯坦望远镜的模拟标准汽笛目录,重建共动距离及其导数,并利用导数敏感诊断量识别区分不同宇宙学模型的最佳红移窗口。

Comments 34 pages, 20 figures + Appendices

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AI中文摘要

未来的引力波标准汽笛目录将探测传统电磁观测难以触及的红移范围内宇宙晚期膨胀历史。为确定这种背景距离信息区分可行宇宙学模型的有效性,我们引入了一个利用高斯过程回归(GPR)的模型无关重建框架。分析六个基准宇宙学背景——ΛCDM、CPL、CPL+Λ、相互作用暗物质、相互作用暗能量和轴子启发早期暗能量——下的模拟LISA和爱因斯坦望远镜(ET)目录。我们重建了共动距离及其导数。关键的是,我们传播了完整的GP协方差,包括导数交叉协方差,以稳健地评估哈勃参数$H(z)$及其他诊断量,如$q(z)$、$\mathcal{O}_{m}(z)$、$w_{ m total}(z)$和$\kappa(z)$。虽然我们的分析表明GW亮标准汽笛能忠实恢复基准膨胀历史,但应用逐点边缘Hellinger距离显示,仅背景测量无法提供模型间的决定性统计分离。相反,导数敏感诊断量精确指出了未来目录将最大化其区分能力的特定红移窗口(例如,ET的$z\simeq1.6-1.8$和LISA的$z\simeq2.6-2.9$)。随着机器学习方法在天体物理学和宇宙学中日益不可或缺,这一贝叶斯GPR流程提供了一种原则性的非参数方法,以精确识别最有价值的宇宙学信息所在之处。

英文摘要

Future gravitational wave (GW) standard siren catalogues will probe the late-time expansion history of the Universe across redshift ranges largely inaccessible to traditional electromagnetic observations. To determine how effectively this background distance information can distinguish between viable cosmological models, we introduce a model-independent reconstruction framework utilizing Gaussian Process Regression (GPR). Analyzing mock LISA and Einstein Telescope (ET) catalogues across six fiducial cosmological backgrounds-$Λ$CDM, CPL, CPL+$Λ$, interacting dark matter, interacting dark energy and axion inspired early dark energy. We reconstruct the comoving distance and its derivatives. Crucially, we propagated the full GP covariance, including derivative cross-covariances, to robustly evaluate the Hubble parameter $H(z)$ and other diagnostics such as $q(z)$, $\mathcal{O}_{m}(z)$ $w_{\rm total}(z)$ and $κ(z)$. While our analysis demonstrates that GW bright standard sirens faithfully recover fiducial expansion histories, applying pointwise marginal Hellinger distance reveals that background measurements alone do not provide decisive statistical separation among models. Instead, derivative sensitive diagnostics pinpoint specific redshift windows (e.g., $z\simeq1.6-1.8$ for ET and $z\simeq2.6-2.9$ for LISA) where future catalogues will maximize their discriminatory power. As machine learning methodologies become increasingly integral to astrophysics and cosmology, this Bayesian GPR pipeline offers a principled, nonparametric approach to precisely identifying where the most valuable cosmological information lies.

2605.27356 2026-05-27 cond-mat.quant-gas cond-mat.supr-con

Quantum Resistance Paradox of Low-Dimensional Superfluids

低维超流体的量子电阻悖论

Simon Wili, Meng-Zi Huang, Tommaso Bonaccorsi, Michael Mühlematter, Mohsen Talebi, Yaakov Yudkin, Alex Gómez-Salvador, Filip Marijanovic, Eugene Demler, Tilman Esslinger

AI总结 通过无缺陷均匀费米气体在数字可编程输运几何中的实验,发现从一维到二维的交叉中电阻达到最小值,揭示了相滑移和涡旋两种耗散机制之间的转变。

Comments 12 pages, 6 figures

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AI中文摘要

标准导体中的电阻随横截面积增大而减小。然而,在低维超导体和超流体中,剩余电阻源于序参量的拓扑涨落,表现为一维系统中的相滑移和二维系统中的涡旋。当几何结构在这些区域之间插值时,电阻和耗散如何演变仍是一个悬而未决的问题。这种演变在固态实验中因无序、杂质和几何缺陷而被掩盖,并且由于竞争性的耗散过程和显著的有限尺寸效应而带来理论挑战。在这里,我们使用数字可编程输运几何中的无缺陷均匀费米气体来隔离几何效应对超流体耗散的影响,并发现一个悖论:在一维到二维的交叉中,电阻达到最小值。在那里,加宽通道会增加其电阻。更窄的准一维通道表现出由Langer-Ambegaokar-McCumber-Halperin相滑移理论描述的耗散。在这个区域,改变通道宽度使得激活因子的指数标度在超过十个数量级上得到验证。更宽的准二维通道表现出与有限尺寸涡旋模型一致的耗散。维度交叉中的最小耗散反映了主导耗散机制的转变,其中相滑移和涡旋同时被抑制。我们的测量为最小化超导器件中的耗散提供了一条途径,并为旨在描述维度交叉的理论工作提供了基准。

英文摘要

Resistance in standard conductors decreases with increasing cross-section. Yet, in low-dimensional superconductors and superfluids residual resistance arises from topological fluctuations of the order parameter manifesting as phase slips in one-dimensional (1D) and vortices in two-dimensional (2D) systems. How resistance and dissipation evolve as geometry interpolates between these regimes remains an open question. This evolution is masked in solid-state experiments by disorder, impurities, and geometric imperfections, and poses theoretical challenges due to competing dissipative processes and pronounced finite-size effects. Here, we use a defect-free unitary Fermi gas in a digitally programmable transport geometry to isolate geometric effects on superfluid dissipation and discover a paradox: in the crossover from 1D to 2D, the resistance reaches a minimum. There, widening a channel increases its resistance. Narrower, quasi-1D channels show dissipation described by Langer-Ambegaokar-McCumber-Halperin theory of phase slips. In this regime, varying the channel width yields the predicted exponential scaling of the activation factor over more than ten orders of magnitude. Wider, quasi-2D channels show dissipation consistent with a finite-size vortex model. The minimal dissipation in the dimensional crossover reflects a transition in the dominant dissipative mechanism, with both phase slips and vortices simultaneously suppressed. Our measurements suggest a route to minimizing dissipation in superconducting devices and provide a benchmark for theoretical efforts aimed at describing the dimensional crossover.

2605.27353 2026-05-27 astro-ph.EP

Impact of Clouds on the Atmosphere-Mantle Interface of Sub-Neptunes

云对亚海王星大气-地幔界面的影响

Sagnick Mukherjee, Matthew C. Nixon, Luis Welbanks, James Mang, Nicholas F. Wogan, Natasha E. Batalha, Michael R. Line

AI总结 使用PICASO 1D气候模型耦合内部结构和岩浆-大气化学框架,量化云如何改变亚海王星的大气和内部结构,发现云会导致深层加热和浅层冷却,并显著改变界面组成。

Comments Accepted for publication in The Astrophysical Journal Letters, Main Text: Pages 1 to 15, 8 Figures, 1 Table, Appendix: Pages 16 to 22, 4 Figures

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AI中文摘要

亚海王星是我们银河系中最常见的近距离行星类型之一,但其整体组成仍然很大程度上不确定;富含H的包层覆盖岩石核心、富含挥发物的行星和富含碳的内部都是这一群体成员的可行配置。大气表征已被提议作为区分这些情景的手段,但越来越多的证据表明,亚海王星可能拥有熔融的大气-地幔界面,这可能会改变其大气成分。我们使用PICASO 1D气候模型,结合内部结构和岩浆-大气化学框架,量化云如何改变亚海王星的大气和内部结构。对于像TOI-270 d这样的温带亚海王星,我们发现云可以导致深层(约10^4 bar)加热≥1000 K,以及在浅层压力(约1 bar)下冷却约600 K。这种加热对云沉降效率非常敏感,对金属丰度敏感程度较低。我们样本中的大多数亚海王星应该具有熔融的大气-地幔界面,除了TOI-1231 b和GJ 1214 b。对于这两颗行星,多云模型具有熔融界面,而晴空模型可能允许固体边界。对于我们样本中的大多数亚海王星,云可以使大气-地幔界面加热约1400-2600 K的温度差。这种云驱动的加热可以显著改变界面的组成,在TOI-270 d的多云和晴空模型中,O₂、SiH₄和SiO的丰度增加了≥36%。我们讨论了我们的结果对这一群体的热演化和内部热通量测量的影响。

英文摘要

Sub-Neptunes are among the most common type of close-in planets found in our galaxy, yet their bulk composition remains largely uncertain; H-rich envelopes overlaying rocky cores, volatile-rich planets, and carbon-rich interiors all remain viable configurations for members of this population. Atmospheric characterization has been proposed as a means of distinguishing between these scenarios, but growing evidence suggests that sub-Neptunes may host molten atmosphere-mantle interfaces which could alter the composition of their atmosphere. We use the PICASO 1D climate model, coupled to interior-structure and magma-atmosphere chemistry frameworks to quantify how clouds alter the atmospheric and interior structure of sub-Neptunes. For temperate sub-Neptunes like TOI-270 d, we find that clouds can lead to $\ge{1000}$ K heating at depth (${\sim}10^{4}$ bar) and $\sim{600}$ K cooling at shallow pressures ($\sim$1 bar). This heating is very sensitive to the cloud sedimentation efficiency and, to a lesser extent, to metallicity. Most sub-Neptunes in our sample should have a molten atmosphere-mantle interface, except TOI-1231 b and GJ 1214 b. For these two planets, cloudy models have a molten interface whereas clear models can allow a solid boundary. Clouds can heat the atmosphere-mantle interfaces by a temperature difference between $\sim{1400}-2600$ K for most sub-Neptunes in our sample. Such cloud-driven heating can substantially change the composition of the interface with abundances of O$_2$, SiH$_4$, and SiO showing a $\ge{36}$\% increase between cloudy and clear models of TOI-270 d. We discuss the implications of our results for the thermal evolution and measurements of intrinsic heat flux for this population.

2605.27350 2026-05-27 quant-ph cond-mat.mes-hall cond-mat.stat-mech cond-mat.str-el

Postselection-free ballistic-diffusive transition in monitored spin chains

受监测自旋链中无后选择的弹道-扩散转变

K. G. S. H. Gunawardana, Ali G. Moghaddam, Teemu Ojanen

AI总结 研究周期性监测下自旋1/2 XXZ链的自旋与纠缠动力学,发现两种测量诱导的相变:稳态纠缠相变和瞬态动力学中的弹道-扩散转变,后者无需后选择即可观测,是实验可及的多体Zeno效应表现。

Comments 12 pages, 5 figures

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AI中文摘要

我们研究了周期性监测下自旋1/2 XXZ链的自旋与纠缠动力学,并表明该系统表现出两种测量诱导的相变:类似于受监测量子电路中的稳态纠缠相变,以及瞬态动力学中的弹道到扩散转变。具体来说,我们发现低监测率下,包含畴壁$|\uparrow\uparrow\uparrow\ldots \downarrow\downarrow\downarrow\ldots\rangle$的初始构型呈弹道扩散,而高监测率下,畴熔化是扩散性的。大量数值模拟及理论论证表明,弹道-扩散转变与纠缠相变密切相关。与需要指数复杂后选择的纠缠相变不同,弹道-扩散转变无需后选择即可观测,构成了多体Zeno效应的实验可及表现。

英文摘要

We study spin and entanglement dynamics in spin-1/2 XXZ chains under periodic monitoring and show that this system exhibits two measurement-induced phase transitions: a steady-state entanglement phase transition similar to those in monitored quantum circuits and a ballistic-to-diffusive transition in transient dynamics. Specifically, we discover that at low monitoring rate, an initial configuration containing a domain wall $|\uparrow\uparrow\uparrow\ldots \downarrow\downarrow\downarrow\ldots\rangle$ spreads ballistically while, at large monitoring rates, the domain melting is diffusive. Extensive numerical simulations, supported by theoretical arguments, indicate that the ballistic-diffusive transition is intimately interlinked with the entanglement phase transition. In contrast to the entanglement phase transitions, which require exponentially complex postselection, the ballistic-diffusive transition can be observed without postselection and constitutes an experimentally accessible manifestation of the many-body Zeno effect.

2605.27349 2026-05-27 cs.SI

Exploring Agent Interactions in MoltBook through Social Network Analysis

通过社交网络分析探索MoltBook中的智能体交互

I-Hsien Ting, Kazunori Minetaki, Dario Liberona, Mu-En Wu

AI总结 本研究提出一个多维分析框架,结合社交网络分析、情感分析和主题可视化,解码MoltBook平台中基于大语言模型的智能体之间的交互语义和情感,并聚焦于智能体原生通信的内在机制。

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AI中文摘要

基于大语言模型的多智能体系统的快速发展已经改变了数字通信,像MoltBook这样的平台作为观察自主社交行为的智能体原生环境而出现。虽然现有文献已经记录了这些网络的结构拓扑,但在理解智能体话语的语义内容和情感暗流方面仍然存在关键空白。在本研究中,我们提出了一个多维分析框架,利用人类-AI协作,借助由Minimax 2.7 LLM驱动的Hermes智能体来促进数据收集和初步分析。我们的方法综合了社交网络分析、情感分析和主题可视化,以解码智能体间的交互。我们认为,将智能体社交动态与人类社交网络进行基准测试本质上是有局限性的;因此,本研究仅关注智能体原生通信的内在机制。通过将结构网络指标与定性诊断相结合,我们提供了MoltBook生态系统内交互质量的整体视图。这种协作方法不仅解决了智能体网络分析中对语义深度的需求,而且为去中心化自主数字网络的新兴动态提供了宝贵的见解。

英文摘要

The rapid evolution of large language model based multiagent systems has transformed digital communication, with platforms like MoltBook emerging as essential agent native environments for observing autonomous social behaviors. While existing literature has documented the structural topology of these networks, there remains a critical gap in understanding the semantic content and emotional undercurrents of agent discourse. In this study, we propose a multi-dimensional analytical framework, utilizing human AI collaboration leveraging the Hermes agent powered by the Minimax 2.7 LLM to facilitate data collection and preliminary analysis. Our methodology synthesizes Social Network Analysis with sentiment analysis and thematic visualization to decode inter-agent interactions. We argue that benchmarking agent social dynamics against human social networks is inherently limited; thus, this study focuses exclusively on the intrinsic mechanics of agent-native communication. By integrating structural network metrics with qualitative diagnostics, we provide a holistic view of interaction quality within the MoltBook ecosystem. This collaborative approach not only addresses the need for semantic depth in agent network analysis but also offers valuable insights into the emergent dynamics of decentralized autonomous digital networks.

2605.27342 2026-05-27 cond-mat.other

Phase-Topology Classification of Memristor Hysteresis Loops via Self-Crossings

忆阻器迟滞回线的相-拓扑分类:基于自交叉点

Ovidiu-Zeno Lipan, Eric Neuhaus, Rafael Schio Wengenroth Silva, Soumen Pradhan, Fabian Hartmann, Leonardo K. Castelano, Ana Luiza Costa Silva, Sven Höfling, Victor Lopez-Richard

AI总结 本文引入拓扑与代数框架,将忆阻器迟滞回线的横向自交点数作为鲁棒的整数值不变量,利用微分拓扑、奇点理论和尖点突变,通过判别式和结式对六维参数空间进行分层,实现所有多叶迟滞行为的完整分类。

Comments 14 pages, 12 figures

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AI中文摘要

忆阻器件革新了非易失性存储和神经形态计算,但其迟滞回线的几何结构——特别是多个自交叉点的出现和鲁棒性——仍知之甚少。本文引入一个拓扑和代数框架,将忆阻器迟滞回线的横向自交点数视为一个鲁棒的整数值不变量。借助微分拓扑、奇点理论和尖点突变,我们使用判别式和结式对六维参数空间进行分层。该方法将参数空间划分为结构稳定的区域,这些区域由可显式计算的突变面分隔。我们证明了交叉数在连续变形下严格不变,仅在自切或尖点奇点处发生变化,从而提供了所有多叶迟滞行为的完整分类。这些见解将器件物理学与现代奇点理论联系起来,并为在下一代电子学和类脑硬件中利用高阶记忆效应提供了清晰的路线图。

英文摘要

Memristive devices have revolutionized non-volatile memory and neuromorphic computing, yet the geometry of their hysteresis loops -- in particular, the occurrence and robustness of multiple self-crossings -- remains poorly understood. Here we introduce a topological and algebraic framework that treats the number of transverse self-intersections of a memristor hysteresis loop as a robust integer-valued invariant. Drawing on differential topology, singularity theory, and cusp catastrophe, we employ discriminants and resultants to stratify the six-dimensional parameter space. This approach partitions the parameter space into structurally stable regions separated by explicitly computable catastrophe surfaces. We demonstrate that the crossing number remains strictly invariant under continuous deformations and changes only at self-tangencies or cusp singularities, thereby providing a complete classification of all multi-lobed hysteresis behaviors. These insights bridge device physics with modern singularity theory and suggest a clear roadmap for exploiting higher-order memory effects in next-generation electronics and brain-inspired hardware.

2605.27341 2026-05-27 math.AP math-ph math.MP

Spectral property for the 2D Zakharov-Kuznetsov equation

二维Zakharov-Kuznetsov方程的谱性质

Justin Holmer, Svetlana Roudenko

AI总结 本文研究二维Zakharov-Kuznetsov方程维里算子的谱性质,通过解析分析将问题简化为数值验证内积符号和特征值,为孤立波的爆破或渐近稳定性提供关键要素。

Comments published version: https://link.springer.com/article/10.1134/S0040577926030037 (translation available) (transl. in Teor. Mat. Fiz. https://doi.org/10.4213/tmf11062)

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Journal ref
Theor. Math. Phys., vol. 226, 2026, p.404-422
AI中文摘要

我们讨论了二维Zakharov-Kuznetsov (ZK) 方程维里算子的谱性质。这是建立高维问题中孤立波爆破或渐近稳定性的关键要素。该模型在三维情形下最初由Zakharov和Kuznetsov在等离子体物理中引入,也是著名的Korteweg-de Vries (KdV) 方程的高维推广。ZK方程中孤立波的稳定性或修正ZK(或KdV型)方程中的稳定爆破是一个重要的物理问题,其中维里算子及其谱性质是分析的基本要素。在本文中,我们解析地研究该问题,并将其简化为仅需数值验证某些内积的符号和某些特征值。

英文摘要

We discuss a spectral property for the virial operator of the 2D Zakharov-Kuznetsov (ZK) equation. This is a crucial ingredient to establish blow-up or asymptotic stability of solitary waves in higher-dimensional problems. This model in 3D setting was originally introduced by Zakharov and Kuznetsov in plasma physics, and is also a higher-dimensional generalization of the well-known Korteweg-de Vries (KdV) equation. The problem of stability of solitary waves in ZK equation or stable blow-up in modified ZK (or KdV-type) equation is an important physical question, for which virial operators and their spectral properties are the essential elements of the analysis. In this paper we investigate this problem analytically and reduce it to verifying numerically only some signs of inner products and certain eigenvalues.

2605.27340 2026-05-27 physics.ins-det hep-ex

Closed-Form Analytical Charge Response Model for Silicon Photomultipliers with Recursive Correlated Avalanches

具有递归相关雪崩的硅光电倍增管的闭式解析电荷响应模型

Yiqi Liu, Xuewei Liu, Benda Xu

AI总结 针对硅光电倍增管(SiPM)的完整电荷响应谱,提出一种无需截断和数值卷积的闭式解析模型,通过特征函数框架统一处理基底噪声、单电子响应、光学串扰和后脉冲效应,并推导出用于事件级能量重建的显式电荷-时间似然函数。

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AI中文摘要

硅光电倍增管(SiPM)已成为下一代中微子实验的首选光电探测器,然而,对于其完整的电荷响应谱,目前尚未建立统一的、无截断和数值卷积的闭式解析表达式,该表达式必须同时捕捉传统光电倍增管(PMT)中不存在的相关串扰和后脉冲效应。我们在特征函数框架内提出了一种统一的SiPM电荷响应闭式模型,将基底噪声、单电子响应(SER)电荷、内部光学串扰和后脉冲同等对待。特征函数表示将完整的电荷谱分解为三个独立的物理分量:基底、单电子响应(SER)和雪崩计数统计。瞬时光学串扰被建模为具有泊松后代的Galton-Watson分支过程;基于Vinogradov识别的广义泊松计数统计,我们通过Lagrange-Bürmann反演推导出总后代概率生成函数(PGF)的Lambert $W$闭式,为高效的事件级重建提供了解析工具。后脉冲被建模为每次雪崩的几何链,推导为最大熵泊松-伽马混合:指数先验(对于具有固定均值的正连续产额的最大熵)在泊松计数上边缘化后,得到每次雪崩的几何分布,其$N$次雪崩总和为负二项分布。这自然包含了泊松后脉冲极限和递归后脉冲链,同时保持了解析闭式性。所得八参数表达式进一步用于推导显式的每通道电荷-时间似然函数,用于事件级能量重建,而无需在推理时进行数值卷积。

英文摘要

Silicon photomultipliers (SiPMs) have become the preferred photodetectors in next-generation neutrino experiments, yet no unified closed-form analytical expression free of truncation and numerical convolution has been established for their full charge response spectrum, which must simultaneously capture correlated cross-talk and afterpulsing effects absent in conventional photomultiplier tubes (PMTs). We present a unified closed-form model for the SiPM charge response within the characteristic-function framework, treating pedestal noise, single-electron-response (SER) charge, internal optical cross-talk, and afterpulsing on equal footing. The characteristic-function representation factorises the full charge spectrum into three independent physical components: pedestal, single-electron response (SER), and avalanche count statistics. Prompt internal optical cross-talk is modelled as a Galton-Watson branching process with Poisson offspring; building on the Generalised Poisson count statistics identified by Vinogradov, we derive a Lambert $W$ closed form for the total-progeny PGF via Lagrange-Bürmann inversion, providing the analytical handle needed for efficient event-level reconstruction. Afterpulsing is modelled as a per-avalanche geometric chain, derived as the maximum-entropy Poisson-Gamma mixture: the exponential prior-maximum-entropy for a positive continuous yield with fixed mean-marginalised over a Poisson count yields the geometric per-avalanche distribution, whose $N$-avalanche total is Negative Binomial. This naturally encompasses the Poisson afterpulsing limit and recursive afterpulse chains while preserving analytical closure. The resulting eight-parameter expression is further applied to derive an explicit per-channel charge-time likelihood for event-level energy reconstruction without numerical convolution at inference time.

2605.27339 2026-05-27 math.OC

Learning to reoptimize: a GNN-aided fix-and-optimize approach and an application to the Lot Sizing problem

学习重新优化:一种GNN辅助的固定与优化方法及其在批量问题中的应用

Mathieu Lerouge, Andrea Lodi, Enrico Malaguti, Michele Monaci, Filippo Focacci

AI总结 提出一种基于图神经网络(GNN)辅助的固定与优化策略,用于在机器故障扰动下快速重新优化批量问题(LSP),显著优于基线方法。

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AI中文摘要

在许多运营环境中,通过混合整数线性规划(MILP)建模的NP难组合优化问题的解可能因不可预测的扰动而变得不可行。通常,通过在扰动实例上求解MILP公式进行重新优化是不可能的,因为必须在极短的计算时间内获得新解,而简单的修复启发式方法可能导致低质量的解。为了弥补这一差距,我们提出了一种学习重新优化框架,并将其应用于机器故障扰动下的批量问题(LSP)。我们设计了一种由图神经网络(GNN)辅助的固定与优化策略,该策略在修复解的邻域内高效计算新解。通过将实例、原始解和扰动表示为特征图,我们训练GNN预测特定二元变量需要修改的可能性。这些预测指导选择一小部分变量由MILP求解器重新优化,而其他变量则被固定。在大型数据集上的数值实验表明,我们的方法有效处理不同问题规模,并且显著优于基线替代方法,在相同的有限时间预算内实现更大的成本降低。

英文摘要

In many operational contexts, solutions to NP-hard combinatorial optimization problems, modeled by means of Mixed-Integer Linear Programming (MILP), may become infeasible due to unpredictable disruptions. Typically, reoptimizing by solving the MILP formulation on the perturbed instance is not possible as new solutions must be obtained in a very short computing time, while simple repairing heuristics may result in low-quality solutions. To bridge this gap, we propose a learning-to-reoptimize framework, and apply it to the Lot Sizing Problem (LSP) under machine breakdown disruptions. We design a fix-and-optimize strategy aided by a Graph Neural Network (GNN) that efficiently computes a new solution within the neighborhood of a repaired solution. By representing the instance, the original solution and the disruption as a feature graph, we train a GNN to predict the likelihood that specific binary variables require to be modified. These predictions guide the selection of a small subset of variables to be reoptimized by an MILP solver, while the other variables are hard-fixed. Numerical experiments on a large dataset demonstrate that our approach handles effectively different problem sizes, and that it significantly outperforms a baseline alternative approach, yielding larger cost reductions within the same limited time budget.

2605.27337 2026-05-27 math.AC

Regular rings and perfectoid towers

正则环与完美塔

Kazuki Hayashi

AI总结 本文通过完美塔证明了Kunz定理的混合特征类比:剩余特征为p的诺特局部环是正则的当且仅当它存在一个平坦映射到可扩展为完美塔的诺特环。

Comments 15 pages

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AI中文摘要

我们证明了Kunz定理在完美塔意义下的混合特征类比:剩余特征为$p$的诺特局部环是正则的当且仅当它存在一个平坦映射到一个诺特环,该映射可扩展为一个完美塔。这一结果是从O. Gabber和J. Lurie的另一个混合特征类比推导出来的。我们还通过剩余域与完美代数的单个高阶$\mathrm{Tor}$模的消失来刻画完美塔的正则性。

英文摘要

We prove a mixed-characteristic analogue of Kunz's theorem in terms of perfectoid towers: a Noetherian local ring of residue characteristic $p$ is regular if and only if it admits a flat map to a Noetherian ring that extends to a perfectoid tower. This result is deduced from another mixed-characteristic analogue due to O. Gabber and J. Lurie. We also characterize regularity for perfectoid towers via vanishing of single higher $\mathrm{Tor}$-module of the residue field with a perfectoid algebra.

2605.27335 2026-05-27 stat.AP

Beyond average warming: Two-sample inference for dense-sparse functional data reveals changes in intraday temperature patterns

超越平均变暖:密集-稀疏函数数据的双样本推断揭示日内温度模式的变化

Kevin Wilk, Hajo Holzmann

AI总结 针对历史与当前温度数据采样频率不一致的问题,提出基于迁移学习的函数型数据双样本推断方法,估计均值函数差并构建均匀置信带,发现气候变化不仅影响平均温度,还改变了日内温度模式。

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AI中文摘要

德国现代气象站每10分钟记录一次每日温度,而历史参考期的测量通常只有更粗的时间分辨率,通常是每小时一次。在比较历史和当前的每日温度模式时,必须考虑这种差异。受此问题启发,我们针对一种样本密集观测而另一种相对稀疏的采样方案,开发了函数型数据的双样本推断程序。基于函数型数据迁移学习的最新思想,我们推导了均值函数差的估计量,该估计量在最大模下达到最优收敛速度。我们进一步在连续函数空间中建立了函数中心极限定理,并开发了乘子自助法来构建均匀置信带。还讨论了向函数型时间序列的扩展。将所提出的方法应用于德国气象站的每日温度曲线,并按月分别分析,结果表明气候变化不仅改变了平均温度,还改变了日内温度模式。特别是,对于柏林等站点,从早晨到下午早期的变暖幅度超过了每日平均增幅,而傍晚和夜间温度的增加相对较小。

英文摘要

Modern weather stations in Germany record daily temperatures every 10 minutes, whereas measurements from historical reference periods are often only available at much coarser temporal resolutions, typically hourly. This discrepancy must be accounted for when comparing historical and current daily temperature patterns. Motivated by this problem, we develop two-sample inference procedures for functional data under sampling schemes where one sample is densely observed while the other is relatively sparse. Building on recent ideas from transfer learning for functional data, we derive estimators of the difference of the mean functions that attain optimal convergence rates in the supremum norm. We further establish a functional central limit theorem in the space of continuous functions and develop multiplier bootstrap methods for constructing uniform confidence bands. Extensions to functional time series are also discussed. Applying the proposed methodology to daily temperature curves from German weather stations, analyzed separately by month, reveals that climate change has altered not only average temperatures but also intraday temperature patterns. In particular, for stations such as Berlin, warming from morning to early afternoon exceeds the daily average increase, whereas evening and nighttime temperatures exhibit comparatively smaller increases.

2605.27334 2026-05-27 astro-ph.HE

Supermassive Black Holes: modelling strongly and weakly magnetised misaligned accretion disks

超大质量黑洞:强磁化和弱磁化错位吸积盘的建模

Joshua Samuel Stanway, Cora Prather, Derek Ward-Thompson, Timothy J. Walton, Brett Patterson, Hyerin Cho

AI总结 通过GRMHD模拟研究不同初始错位角和磁场配置下的吸积盘,发现磁抑制盘(MAD)状态可使盘在极端错位下与黑洞对齐,而弱磁场盘保持错位且最大倾斜角约50°。

Comments 13 pages, 12 figures

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AI中文摘要

在本文中,我们对旋转超大质量黑洞周围的错位吸积盘进行了数值研究。我们使用广义相对论磁流体动力学(GRMHD)代码KHARMA,进行了一项参数调查,涵盖了初始盘错位角($\mathcal{T}_\mathrm{init}=15^\circ, 45^\circ, 75^\circ$)的范围,并采用了磁抑制盘(MAD)或标准正常演化(SANE)磁场配置。我们发现,MAD状态下的模型可以与黑洞对齐至约$10 \, r_g$,即使在极端错位模型($\mathcal{T}_\mathrm{init}=75^\circ$)中也是如此,这是以前未曾见过的。没有动态重要磁场的模型在黑洞附近仍然保持错位,最大盘倾斜出现在约$10 \, r_g$处,峰值距黑洞的径向距离随盘错位增加而增加。然而,最大盘倾斜与初始盘错位并非线性关系,且似乎有一个最大值约$50^\circ$。我们还展示了KHARMA产生的错位盘模拟结果与其它GRMHD代码在多种问题下是一致的。

英文摘要

In this paper, we carry out a numerical study of misaligned accretion disks around spinning supermassive black holes. Here, we conduct a parameter survey covering a range of initial disk misalignment angles ($\mathcal{T}_\mathrm{init}=15^\circ, 45^\circ, 75^\circ$) with either the Magnetically Arrested Disk (MAD) or Standard And Normal Evolution (SANE) magnetic field configurations, using the general-relativistic magnetohydrodynamic (GRMHD) code KHARMA. We find that models in the MAD state can align with the black hole up to $\sim10 \, r_g$, even in extremely misaligned models ($\mathcal{T}_\mathrm{init}=75^\circ$), which has not been seen before. Models without a dynamically important magnetic field remain misaligned up to the black hole, with a maximum disk tilt at $\sim10 \, r_g$, the peak's radial distance from the black hole increases with increasing disk misalignment. However, the maximum disk tilt does not have a linear relationship with the initial disk misalignment, and appears to have a maximum value of $\sim50^\circ$. We also show misaligned disk simulations produced in KHARMA are consistent with other GRMHD codes, for a variety of problems.

2605.27330 2026-05-27 stat.ME

Two-Phase Sampling Designs and Analysis Approaches for Ordinal Outcomes

面向有序结局的两阶段抽样设计与分析方法

Yunbi Nam, Nathan I. Shapiro, Eric P. Schmidt, Wesley H. Self, Ran Tao, Jonathan S. Schildcrout

AI总结 针对有序结局变量,提出三种基于结局的第二阶段抽样设计(ODS、协变量分层ODS和残差依赖抽样)以及相应的校正分析方法,显著提高估计效率。

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AI中文摘要

现代临床试验和队列研究收集所有参与者的低成本数据,但可能资源有限,无法评估昂贵的暴露因素(如生物标志物或基因组数据)。当关注涉及昂贵暴露的关联时,两阶段设计通过利用所有参与者的可用信息来指导目标选择子集进行额外测量,从而提供了一种成本效益高的框架。我们将此框架扩展到具有有序结局的研究中,这是一个常见但先前未探索的设置。我们提出了三种基于结局的第二阶段抽样设计——结局依赖抽样(ODS)、协变量分层ODS和残差依赖抽样——利用第一阶段数据丰富第二阶段选择的信息性受试者。然后,我们开发了用于有效且高效估计/推断的分析方法,包括使用校正最大似然估计的条件似然方法、多重插补以及使用筛最大似然估计的全似然方法。在一系列场景中,模拟研究表明,与使用标准最大似然估计的简单随机抽样相比,所提出的方法显著提高了效率。我们通过检查白细胞介素-6与四水平临床状态结局(出院、住院但不在ICU、住院在ICU和死亡)之间的关联,进一步证明了其实用性,该数据来自Crystalloid Liberal or Vasopressors Early Resuscitation in Sepsis试验随机化后14天的结果。

英文摘要

Modern clinical trials and cohort studies gather low-cost data on all participants but may have limited resources to assess expensive exposures such as biomarkers or genomic data. When interest lies in associations involving expensive exposures, two-phase designs provide a cost-effective framework by using information available on all participants to guide the targeted selection of a subset for additional measurements. We extend this framework to studies with ordinal outcomes, a common yet previously unexplored setting. We propose three outcome-informed phase 2 sampling designs -- outcome-dependent sampling (ODS), covariate-stratified ODS, and residual-dependent sampling -- that leverage phase 1 data to enrich phase 2 selection with informative subjects. We then develop analysis methods for valid and efficient estimation/inference, including conditional likelihood methods with ascertainment-corrected maximum likelihood estimation, multiple imputation, and a full likelihood method using sieve maximum likelihood estimation. Across a range of scenarios, simulation studies show that the proposed methods substantially improve efficiency over simple random sampling with standard maximum likelihood estimation. We further demonstrate their practical utility by examining the association between interleukin-6 and a four-level clinical status outcome -- discharged, hospitalized but not in the ICU, hospitalized in the ICU, and death -- 14 days after randomization into the Crystalloid Liberal or Vasopressors Early Resuscitation in Sepsis trial.

2605.27329 2026-05-27 math.FA

Operator $K$-Positivity Preserver

算子 $K$-正性保持

Lars-Luca Langer

AI总结 研究在 $\mathbb{R}^n$ 和紧集 $K$ 上保持正性的映射 $T$,并由此刻画局部算子矩序列和一般算子矩序列。

Comments 11 pages

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AI中文摘要

我们刻画了在 $\mathbb{R}^n$ 和紧集 $K \subseteq \mathbb{R}^n$ 上保持正性的映射 $T: B(\mathcal{H})_h \otimes \mathbb{R}[x_1, \dots, x_n] o B(\mathcal{H})_h \otimes \mathbb{R}[x_1, \dots, x_n]$。这也通过正性保持映射刻画了局部算子矩序列和一般算子矩序列。

英文摘要

We characterize positivity preserving maps $T: B(\mathcal{H})_h \otimes \mathbb{R}[x_1, \dots, x_n] \to B(\mathcal{H})_h \otimes \mathbb{R}[x_1, \dots, x_n]$ on $\mathbb{R}^n$ and on compact sets $K \subseteq \mathbb{R}^n$. This also characterizes local operator moment sequences and general operator moment sequences via positivity preserving maps.

2605.27327 2026-05-27 math.NA cs.NA

A collocation scheme that is equivalent to discontinuous Galerkin discretizations

一种等价于间断伽辽金离散化的配置方案

Jason Hicken

AI总结 本文证明了一种具有求和-分部性质的谱配置算子产生的半离散化与使用相同底层求积的DG半离散化等价,并研究了等价性条件及数值验证。

Comments 27 pages, 7 figures

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AI中文摘要

Chan 引入了一种具有求和-分部性质的谱配置算子,用于发展熵稳定的间断伽辽金(DG)半离散化(https://doi.org/10.1016/j.jcp.2018.02.033)。本文表明,基于该配置算子的半离散化产生的解与使用相同底层求积的 DG 半离散化的解等价。无论配置方案中的自由度数量如何,以及当求积不严格正定时,该等价性均成立。配置方案中的多余自由度与算子的零空间相关联,并在非定常模拟过程中保持为零。如有必要,可以通过引入仅针对多余模态的基于投影的数值耗散来恢复零空间一致性。在三角形网格上,针对常系数平流方程和 Burgers 方程验证了配置解与 DG 解之间的等价性。数值结果表明,对于基于斜对称分裂的 Burgers 方程的熵稳定半离散化,等价性被破坏,但可以通过将配置方案的残差投影到相关多项式空间上来恢复等价性。除了研究等价性外,结果还表明,与常用的求和-分部算子构造相比,该配置算子产生的半离散化具有更有利的谱半径。

英文摘要

A spectral collocation operator with the summation-by-parts property was introduced by Chan to develop entropy-stable discontinuous Galerkin (DG) semi-discretizations (https://doi.org/10.1016/j.jcp.2018.02.033). The present work shows that semi-discretizations based on this collocation operator produce solutions that are equivalent to solutions of a DG semi-discretization using the same underlying quadrature. The equivalence holds regardless of the number of degrees of freedom in the collocation scheme and when the quadrature is not strictly positive. Extraneous degrees of freedom in the collocation scheme are associated with the nullspace of the operator and remain zero throughout an unsteady simulation. If necessary, nullspace consistency can be recovered by introducing projection-based numerical dissipation that targets only the extraneous modes. The equivalence between collocation and DG solutions is verified for the constant-coefficient advection equation and Burgers' equation on triangular meshes. The numerical results show that equivalence breaks down for entropy-stable semi-discretizations of Burgers' equation based on a skew-symmetric splitting, but that equivalence can be recovered by projecting the collocation scheme's residual onto the relevant polynomial space. In addition to investigating equivalence, the results demonstrate that the collocation operator produces semi-discretizations with favorable spectral radii compared with a commonly used summation-by-parts operator construction.

2605.27326 2026-05-27 quant-ph cond-mat.mes-hall cond-mat.stat-mech

Autonomous oscillations in quantum electromechanics: tensor network treatment

量子电机械系统中的自主振荡:张量网络处理

Mahasweta Pandit, Sheikh Parvez Mandal, Mark T. Mitchison, Javier Prior

AI总结 本文提出张量网络框架,结合振动模式的二进制表示与介观储层嵌入,无需实时传播即可描述纳米电机械系统中由输运诱导的自持振荡,并揭示了强电机械反作用、非绝热振荡器动力学和能量相关电子隧穿过程竞争下的振荡行为。

Comments 23 pages, 11 figures. Comments are welcome!

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AI中文摘要

电机械系统中输运诱导的自持振荡将静态电化学偏压转化为稳健的自主振荡运动,无需任何外部周期驱动。然而,在同时具有大玻色子希尔伯特空间、强相互作用和结构化费米子引线的纳米尺度电机械器件中,对这种自振荡的精确描述仍然具有挑战性。我们制定了一个张量网络框架,该框架将振动模式的二进制表示与介观储层嵌入相结合,无需显式实时传播即可控制地访问自振荡稳态和相关的输运可观测量。我们展示了在广泛的操作条件下机械自振荡的出现,其中强电机械反作用、非绝热振荡器动力学和能量相关的电子隧穿过程相互竞争。此外,我们观察到,对于慢速和快速振动的机械模式,在电机械耦合强度扫描过程中,自振荡窗口内振动占据数涨落的抑制之前会出现占据数涨落的峰值。总的来说,我们探索了内在系统特性和环境参数如何在广泛的操作条件下支配这种自主振荡。我们框架的通用性将使该方法能够直接应用于更复杂或实验相关的场景。

英文摘要

Transport-induced self-sustained oscillations in electromechanical systems convert a static electrochemical bias into robust, autonomous oscillatory motion in the absence of any external periodic drive. However, an exact description of such self-oscillations remains challenging in nanoscale electromechanical devices featuring a simultaneously large bosonic Hilbert space, strong interactions, and structured fermionic leads. We formulate a tensor-network framework that combines a binary representation of the vibrational mode with mesoscopic reservoir embeddings that enable controlled access to the self-oscillatory steady states and relevant transport observables without explicit real-time propagation. We demonstrate the emergence of mechanical self-oscillations across a broad set of operating conditions, in which strong electromechanical backaction, nonadiabatic oscillator dynamics, and energy-dependent electronic tunneling processes compete. Furthermore, we observe that for both slow and fast vibrating mechanical modes, suppressed vibrational occupation fluctuations in the self-oscillation window along the electromechanical coupling strength sweep is preceded by a peak in the occupation fluctuations. Collectively, we explore how both intrinsic system properties and environmental parameters govern such autonomous oscillations over a broad range of operating conditions. The generality of our framework will enable the method to be employed straightforwardly to more complicated or experimentally relevant scenarios.

2605.27325 2026-05-27 cond-mat.mtrl-sci

Microstructure-Aware Deep Learning Bridges Atomistics to Macroscale for Shock-to-Detonation Prediction

微观结构感知的深度学习桥接原子尺度与宏观尺度实现冲击到爆轰预测

Simon Gonzalez-Zapata, Aidan Pantoya, Chunyu Li, Marisol Koslowski, Alejandro Strachan

AI总结 针对含能材料中冲击到爆轰转变的多尺度耦合难题,提出MISTnetX卷积深度神经网络,直接桥接大规模分子动力学模拟与连续介质有限元模型,实现无参数预测完整爆轰转变过程。

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AI中文摘要

含能材料中的冲击到爆轰转变由跨越埃到毫米、飞秒到微秒的耦合过程控制,传统多尺度模型因缺乏尺度分离而失效。我们通过使用卷积深度神经网络MISTnetX直接桥接大规模分子动力学(MD)模拟与连续介质有限元(FE)模型来应对这一重大挑战。MISTnetX在通过复杂微观结构传播的冲击MD模拟上训练,捕捉冲击-微观结构相互作用、热点形成以及向爆燃的转变,为力学、冲击、热输运和化学的FE模拟提供关键的子网格信息。应用于合成但真实的纳米结构塑料粘结RDX复合材料,MISTnetX实现了无参数预测完整的爆轰转变过程。

英文摘要

The shock-to-detonation transition in energetic materials is governed by coupled processes spanning Angstroms to millimeters and femtoseconds to microseconds, where traditional multiscale models fail due to the lack of scale separation. We address this grand challenge by directly bridging large-scale molecular dynamics (MD) simulations with continuum finite-element (FE) models using MISTnetX, a convolutional deep neural network. Trained on MD simulations of shock propagation through complex microstructures, MISTnetX captures shock-microstructure interactions, hotspot formation, and the transition to deflagration, supplying critical sub-grid information to FE simulations of mechanics, shocks, thermal transport, and chemistry. Applied to a synthetic but realistic nanostructured plastic-bonded RDX composite, MISTnetX enables parameter-free prediction of the full run-to-detonation transition.

2605.27324 2026-05-27 gr-qc

Reconstructing the cosmic expansion in $f(R, L_{m})$ gravity via parametrized Hubble function constraints

在 $f(R, L_{m})$ 引力中通过参数化哈勃函数约束重建宇宙膨胀

Khomesh R. Patle, G. P. Singh

AI总结 采用 $f(R, L_{m}) = \frac{R}{2} + L_{m}^\lambda$ 函数形式,引入三种基于红移相关哈勃参数 $H(z)$ 的宇宙学模型,通过贝叶斯方法约束模型参数,研究宇宙膨胀历史及能量条件、态诊断等,并验证热力学可行性。

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AI中文摘要

我们在 $f(R, L_{m})$ 引力框架内,通过采用一个动机良好的函数形式 $f(R, L_{m}) = \frac{R}{2} + L_{m}^\lambda$ 来探测宇宙膨胀情景。具体来说,我们引入了三种新颖的宇宙学模型,这些模型用红移相关的哈勃参数 $H(z)$ 表述,为潜在的宇宙动力学提供了更深入的见解。这些模型进一步用于研究宇宙的膨胀历史以及几个宇宙学参数的演化。通过使用基于 $\chi^{2}$ 最小化技术的贝叶斯方法,针对宇宙计时器(CC)和联合(CC+Pantheon)数据集确定了模型参数的中值。对减速参数、能量密度、压强和状态方程参数进行了全面研究,以理解宇宙的演化。此外,还彻底检查了能量条件的有效性和态诊断的行为。最后,通过温度和熵密度的演化确认了模型的热力学可行性,并且估算的宇宙年龄进一步证明了与晚期天文观测的良好一致性。

英文摘要

We probe the cosmic expansion scenario within the framework of $f(R, L_{m})$ gravity by employing a well-motivated functional form of $f(R, L_{m}) = \frac{R}{2} + L_{m}^λ$. Specifically, we introduce three novel cosmological models formulated in terms of the redshift-dependent Hubble parameter $H(z)$, offering deeper insights into the underlying cosmic dynamics. The models are further utilized to investigate the expansion history of the universe and the evolution of several cosmological parameters. By using the Bayesian methods based on the $χ^{2}$-minimization technique, the median values of the model parameters are determined for the cosmic chronometer (CC) and joint (CC+Pantheon) datasets. A comprehensive study of the deceleration parameter, energy density, pressure and the equation of state parameter is carried out to understand the universe's evolution. Additionally, the validity of the energy conditions and the behavior of the statefinder diagnostic are thoroughly examined. Finally, the thermodynamic viability of the models is confirmed through the evolution of temperature and entropy density, and the estimated age of the universe further exemplifies good agreement with late-time astronomical observations.