Papers

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Physics

Monday 22 June

Strongly Correlated Electrons

Strain-tuned orbital-dependent electronic correlations in FeTe thin films

Hyunjee Song, Sangjae Lee, Keun-Yeol Park et al. (+8 more)

Iron chalcogenides exhibit rich phenomena which are governed by orbital-dependent electronic interactions and strong electronic correlation. In particular, many studies have explored orbital selectivity in FeTe through Se doping. Here, applying tensile strain to thin films allows us to precisely control the system without other impurities that may arise from chemical doping to investigate the emergent behaviors in FeTe. Using angle-resolved photoemission spectroscopy, we observe a spectral weight transfer between $d_{\rm xy}$ and $d_{\rm z^{2}}$ orbitals, evidence of an orbital-selective Mott phase (OSMP). Beyond OSMP, we reveal hitherto unobserved strain-induced effects, distinct from chemical doping. The evolution of $d_{\rm xz}$ orbital demonstrates how electron hopping mechanism plays an important role in defining the electronic properties of the system. Our findings highlight a direct correlation between epitaxial strain and the evolution of electronic structures in FeTe.

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All authors Hyunjee Song, Sangjae Lee, Keun-Yeol Park, Jaehyun Park, Suyoung Lee, Yeonjae Lee, Jinyoung Kim, Jaeung Lee, Celesta S. Chang, Younsik Kim, Changyoung Kim

Soft Condensed Matter

Hierarchical Granular Metamaterials

James Utama Surjadi, Bastien F. G. Aymon, Ayan Kumar et al. (+4 more)

Granular materials dissipate energy efficiently through intergranular interactions, yet their disordered, dense nature precludes precise control and integration into lightweight systems. Architected materials offer tunable mechanical responses at low densities but tend to localize stress, limiting dissipation efficiency. Here, we introduce hierarchical granular metamaterials that reconcile these trade-offs through three levels of design: lightweight architected grains engineered with hollow elliptical inclusions, crystal-inspired grain packings, and functional gradients and defects within grain tessellations. These metamaterials exhibit simultaneous increases in impact energy absorption per unit mass and reductions in transmitted peak force at low densities, outperforming conventional architected materials. In situ nanomechanical experiments and nonlinear computational models reveal that enhanced lateral grain expansion drives recruitment of neighboring grains, amplifying plastic and frictional dissipation. Multiscale impact experiments confirm that these mechanisms persist across length scales, constituent materials, and dimensionalities. Beyond mechanical performance, we demonstrate that spatially programmable inter-grain contact networks enable deterministic routing of deformation, which extends to electrical transport pathways independently of packing geometry. By combining granular principles with architected material design, this work establishes a paradigm for multifunctional metamaterials whose contact topology, mechanical response, and transport properties can be programmed independently.

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All authors James Utama Surjadi, Bastien F. G. Aymon, Ayan Kumar, Lei Wu, Jet Lem, Ken N. Kamrin, Carlos M. Portela

Plasma Physics

Evaluation of spatiotemporal tungsten density profiles using Unresolved Transition Arrays in the Large Helical Device

R. Nishimura, T. Oishi, I. Murakami et al. (+12 more)

Tungsten spectroscopic studies have been conducted in the Large Helical Device with a pellet injection technique. Spatiotemporal profiles of tungsten density were evaluated using a space-resolved spectrometer, for plasmas with an electron temperature of below 1 keV and electron density of $10^{19}-10^{20}$ $m^{-3}$. Slice & Stack, a method for reconstructing emissivity, was applied to a line at 191.7 Å , which is a part of the Unresolved Transition Array (UTA) spectrum at 90-250 Å. Tungsten density was obtained using photon emission coefficients of $\mathrm{W}^{17+} - \mathrm{W}^{27+}$, evaluated from collisional-radiative model. The tungsten pellet injected from outside the plasma was first ablated in the edge plasma and subsequently diffused throughout the plasma. This behavior is typical of pellet injection experiments. Furthermore, after an event triggered by NBI breakdown, tungsten accumulated in the core plasma. The radiation power was estimated from the evaluated tungsten density profile and cooling factor dataset, and compared with bolometer measurement. This sequence of processes would be useful for validating atomic data of tungsten ions in low-to-intermediate charge states.

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All authors R. Nishimura, T. Oishi, I. Murakami, D. Kato, H. A. Sakaue, S. Gupta, H.Ohashi, C. Suzuki, M. Goto, Y. Kawamoto, R.T. Ishikawa, T. Kawate, K. Mukai, B.J. Peterson, H. Takahashi

High Energy Physics (Theory)

Quantized Irreversible Null-geometry: Foundation and Applications

Si-xue Qin

Formulating a consistent integration measure for quantum geometric fluctuations without violating diffeomorphism invariance remains a theoretical challenge. In this work, a framework rooted in the statistics of discrete Poisson point processes is proposed. The formulation yields a double-exponential probability functional characterized by a capacity limit, which acts as an amplitude regularizer suppressing ultraviolet singularities. To evaluate this model at macroscopic scales, a statistical bifurcation of the stochastic action is identified. First, the macroscopic mean condenses to define the classical continuous spacetime background and its matter distribution. Second, at macroscopic scales, the Law of Large Numbers dictates that the residual ultraviolet noise maps into an infrared continuous zero-mean Gaussian martingale within the bulk. Third, this zero-mean Gaussian noise linearly generates standard quantum kinematic effects. Fourth, evaluating the non-linear exponential action separates the variance of this Gaussian noise from the linear cancellation, rectifying it into a macroscopic drift that manifests as the dark energy density. Diluted by the Bekenstein-Hawking entropy of the observable universe, this bulk variance dictates a continuous field cutoff at 6 TeV. Building upon this framework, broad phenomenological applications are demonstrated: (1) establishing a UV-finite effective field theory preserving gauge symmetries in 4D; (2) constructing a topological model of particles deriving Standard Model hierarchies; (3) formulating a non-singular cosmological model predicting observed large-scale power suppression in the cosmic microwave background; and (4) deriving foundational axioms of quantum mechanics as emergent statistical phenomenologies. Collectively, this framework provides a falsifiable synthesis bridging discrete quantum geometry and continuous macroscopic physics.

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Optics

Autonomous Generation of Metamaterial Databases Based on Multimodal Agents

Shilong Qin, Zhicai Yu, Xuan Zheng et al. (+6 more)

Artificial intelligence (AI) is revolutionizing material research and discovery. However, its development in metamaterials is bottlenecked by a shortage of high-quality and executable structure-response databases, which are locked within scientific literatures as a mixture of text and images. Converting the rapidly growing body of scientific literatures into executable and reusable databases for machine-driven discovery is still a fundamental challenge. Here, we propose MetaDataGenAgent, a multimodal multi-agent framework that autonomously converts unstructured scientific literatures directly into metamaterial structure-response databases. MetaDataGenAgent establishes a complete literature-to-simulation pipeline through the coordinated operation of specialized agents for multimodal parameter extraction, physics-guided validation, topology-aware structural analysis, and solver-executable encoding. The framework introduces a closed-loop plan-execute-reflect mechanism that enables dynamic task decomposition, iterative validation, and feedback-driven model construction. Experimental results validate that MetaDataGenAgent can generate high-fidelity structure-response data for representative meta-atoms, which are further used to realize diverse electromagnetic functions, including far-field beam deflection, near-field holographic imaging and topologically protected surface-wave transport. By establishing an autonomous route from scientific literatures to AI-ready databases, the framework provides a general and efficient strategy that could be extended to a broad range of data-scarce scientific domains, including photonics, materials science, chemistry, computational science, and scientific automation.

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All authors Shilong Qin, Zhicai Yu, Xuan Zheng, Yan Zhang, Aodi Yang, Kezhan Zhao, Qi Cheng Chen, Jian Wei You, Tie Jun Cui

Mathematical Physics

Why Hadamard states?

Eleanor March

In QFT on curved spacetime, the Hadamard condition is often presented as a necessary condition on 'physically reasonable' states of the quantum field, and plays a central role in many theoretical and foundational applications - ranging from proofs of the renormalizability of Wick polynomials to derivations of the Hawking temperature. Yet despite this, the philosophical and foundational underpinnings of the Hadamard condition remain murky. I critically discuss existing motivations for the Hadamard condition in the literature, before arguing in favour of an alternative motivation for the Hadamard condition, according to which it is best understood as a necessary and sufficient condition for the existence of a well-defined operator product of a certain form on a sufficiently large space of observables of the quantum field, satisfying a variety of further conditions. This clarifies the role and status of the Hadamard condition, including its relationship to the equivalence principle, to well-definedness of physical quantities such as Wick polynomials and the expectation value of the stress-energy operator, and the sense in which Hadamard states are 'vacuum-like'.

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Chaotic Dynamics · Cross-listed from cs.NE

Evolutionary Optimization Reveals Structural Constraints on Reservoir Architecture for Spatiotemporal Chaos

Nima Dehghani

Biological systems maintain function in fluctuating environments by transforming past stimulation into internal dynamical states that support future-oriented responses. Reservoir computing provides a computational analogue, but standard formulations often treat the recurrent substrate as a fixed random network and train only the readout. Here we ask how the substrate itself changes when reservoir architecture is placed under evolutionary selection for prediction. Using the Kuramoto–Sivashinsky equation as a testbed for spatiotemporal chaos, we evolved reservoirs over five construction hyperparameters: size, connectivity degree, spectral radius, input scaling, and readout regularization. Evolution reduced prediction error at the population level, extended the low-error forecast horizon, and organized the design space along a diminishing-return size–efficiency frontier. Structural analyses showed that evolved reservoirs remained within a conserved stochastic-block-model-like spectral envelope while refining low-eigenvalue modes, locking modularity to an intermediate band, and pruning connection cost within that band. Pareto analysis showed that elite reservoirs occupied a horizontal floor in the cost–modularity plane, indicating that accuracy and efficiency were achieved jointly rather than through a simple trade-off. These findings show that evolutionary optimization does not merely improve prediction, but exposes interpretable structural constraints on the recurrent substrate: it stabilizes a task-suitable dynamical class and refines the architectural degrees of freedom most relevant for prediction. Evolutionary reservoir computing therefore provides a bio-inspired framework for studying how predictive demands shape adaptive dynamical networks.

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Astrophysics of Galaxies

Highly filamentary H{\,\small I} gas in the circumgalactic medium and intragalactic medium around NGC 4631

C. Zhang, Tie Liu, Xiaofeng Mai et al. (+1 more)

Neutral hydrogen (H{\,\small I}) in the circumgalactic medium (CGM) and intergalactic medium (IGM) traces baryon cycling and galaxy evolution, yet fine filamentary substructures in diffuse CGM/IGM H{\,\small I} remain poorly constrained observationally. We combine FAST FEASTS single-dish and VLA THINGS interferometric H{\,\small I} data of the NGC 4631 group to report the first robust detection of kpc-scale filamentary structures in the CGM/IGM, with widths of $0.5$-$3.3\ \mathrm{kpc}$ and lengths of $6.1$-$49.8\ \mathrm{kpc}$. These features confirm that low-density CGM/IGM gas hosts velocity coherent substructure. From position-velocity kinematic analysis, we identify three filament classes (U-shaped, linear, and wavy), implying diverse formation mechanisms. Our results establish a structural bridge connecting pc-scale interstellar filaments, kpc-scale CGM/IGM filaments, and Mpc-scale cosmic-web filaments, providing key observational support for multiscale gaseous coupling in cosmic ecosystem.

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All authors C. Zhang, Tie Liu, Xiaofeng Mai, Jing Wang

High Energy Physics (Experiment)

Measurement of Born cross sections for $e^+e^-\to p\bar p$ at $\sqrt{s} =3.510-4.946$ GeV

BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson et al. (+757 more)

We report a measurement of the Born cross section and the effective form factor for the $e^+e^-\to p\bar{p}$ reaction at 47 center-of-mass energies between 3.510 and 4.946 GeV. The measurement is performed using the energy-scan technique and is based on data corresponding to an integrated luminosity of 26 fb$^{-1}$ collected with the BESIII detector at the BEPCII collider. For the first time, the moduli of the electromagnetic form factor ratio $|G_{E}/G_{M}|$ and of the magnetic form factor $|G_{M}|$ are determined with high precision by analyzing the distribution of the polar angle of the proton at a large timelike momentum transfer. These results provide essential insights into the nature of charmonium(-like) states above the open-charm threshold and the dynamics underlying the proton electromagnetic form factors.

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All authors BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, Y. H. An, Y. Bai, O. Bakina, H.-R. Bao, X. L. Bao, M. Barbagiovanni, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, D. Cabiati, H. Cai, M. H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. M. Chen, T. Chen, W. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, E. Di Fiore, X. X. Ding, Y. Ding, Y. X. Ding, Yi. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, Shaoxu Du, X. L. Du, Y. Q. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, Y. H. Fan, J. Fang, Jin Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, L. Feng, Q. X. Feng, Y. T. Feng, M. Fritsch, C. D. Fu, J. L. Fu, Y. W. Fu, H. Gao, Y. Gao, Y. N. Gao, Y. Y. Gao, Yunong Gao, Z. Gao, S. Garbolino, I. Garzia, L. Ge, P. T. Ge, Z. W. Ge, C. Geng, E. M. Gersabeck, A. Gilman, K. Goetzen, J. Gollub, J. B. Gong, J. D. Gong, L. Gong, W. X. Gong, W. Gradl, S. Gramigna, M. Greco, M. D. Gu, M. H. Gu, C. Y. Guan, A. Q. Guo, H. Guo, J. N. Guo, L. B. Guo, M. J. Guo, R. P. Guo, X. Guo, Y. P. Guo, Z. Guo, A. Guskov, J. Gutierrez, J. Y. Han, T. T. Han, X. Han, F. Hanisch, K. D. Hao, X. Q. Hao, F. A. Harris, C. Z. He, K. K. He, K. L. He, F. H. Heinsius, C. H. Heinz, Y. K. Heng, C. Herold, P. C. Hong, G. Y. Hou, X. T. Hou, Y. R. Hou, Z. L. Hou, H. M. Hu, J. F. Hu, Q. P. Hu, S. L. Hu, T. Hu, Y. Hu, Y. X. Hu, Z. M. Hu, G. S. Huang, K. X. Huang, L. Q. Huang, P. Huang, X. T. Huang, Y. P. Huang, Y. S. Huang, T. Hussain, N. Hüsken, N. in der Wiesche, J. Jackson, Q. Ji, Q. P. Ji, W. Ji, X. B. Ji, X. L. Ji, Y. Y. Ji, L. K. Jia, X. Q. Jia, D. Jiang, H. B. Jiang, S. J. Jiang, X. S. Jiang, Y. Jiang, J. B. Jiao, J. K. Jiao, Z. Jiao, L. C. L. Jin, S. Jin, Y. Jin, M. Q. Jing, X. M. Jing, T. Johansson, S. Kabana, X. L. Kang, X. S. Kang, B. C. Ke, V. Khachatryan, A. Khoukaz, O. B. Kolcu, B. Kopf, L. Kröger, L. Krümmel, Y. Y. Kuang, M. Kuessner, X. Kui, N. Kumar, A. Kupsc, W. Kühn, Q. Lan, W. N. Lan, T. T. Lei, M. Lellmann, T. Lenz, C. Li, C. H. Li, C. K. Li, Chunkai Li, Cong Li, D. M. Li, F. Li, G. Li, H. B. Li, H. J. Li, H. L. Li, H. N. Li, H. P. Li, Hui Li, J. N. Li, J. S. Li, J. W. Li, K. Li, K. L. Li, L. J. Li, Lei Li, M. H. Li, M. R. Li, M. T. Li, P. L. Li, P. R. Li, Q. M. Li, Q. X. Li, R. Li, S. Li, S. X. Li, S. Y. Li, Shanshan Li, T. Li, T. Y. Li, W. D. Li, W. G. Li, X. Li, X. H. Li, X. K. Li, X. L. Li, X. Y. Li, X. Z. Li, Y. Li, Y. G. Li, Y. P. Li, Z. H. Li, Z. J. Li, Z. L. Li, Z. X. Li, Z. Y. Li, C. Liang, H. Liang, Y. F. Liang, Y. T. Liang, G. R. Liao, L. B. Liao, M. H. Liao, Y. P. Liao, J. Libby, A. Limphirat, C. C. Lin, C. X. Lin, D. X. Lin, T. Lin, B. J. Liu, B. X. Liu, C. Liu, C. X. Liu, F. Liu, F. H. Liu, Feng Liu, G. M. Liu, H. Liu, H. B. Liu, H. M. Liu, Huihui Liu, J. B. Liu, J. J. Liu, K. Liu, K. Y. Liu, Ke Liu, Kun Liu, L. Liu, L. C. Liu, Lu Liu, M. H. Liu, P. L. Liu, Q. Liu, S. B. Liu, T. Liu, W. M. Liu, W. T. Liu, X. Liu, X. K. Liu, X. L. Liu, X. P. Liu, X. Y. Liu, Y. Liu, Y. B. Liu, Yi Liu, Z. A. Liu, Z. D. Liu, Z. L. Liu, Z. Q. Liu, Z. X. Liu, Z. Y. Liu, X. C. Lou, H. J. Lu, J. G. Lu, X. L. Lu, Y. Lu, Y. H. Lu, Y. P. Lu, Z. H. Lu, C. L. Luo, J. R. Luo, J. S. Luo, M. X. Luo, T. Luo, X. L. Luo, Z. Y. Lv, X. R. Lyu, Y. F. Lyu, Y. H. Lyu, F. C. Ma, H. L. Ma, Heng Ma, J. L. Ma, L. L. Ma, L. R. Ma, Q. M. Ma, R. Q. Ma, R. Y. Ma, T. Ma, X. T. Ma, X. Y. Ma, Y. M. Ma, F. E. Maas, I. MacKay, M. Maggiora, S. Maity, S. Malde, Q. A. Malik, H. X. Mao, Y. J. Mao, Z. P. Mao, S. Marcello, A. Marshall, F. M. Melendi, Y. H. Meng, Z. X. Meng, G. Mezzadri, H. Miao, T. J. Min, R. E. Mitchell, X. H. Mo, B. Moses, N. Yu. Muchnoi, J. Muskalla, Y. Nefedov, F. Nerling, H. Neuwirth, Z. Ning, S. Nisar, Q. L. Niu, W. D. Niu, Y. Niu, C. Normand, S. L. Olsen, Q. Ouyang, S. Pacetti, X. Pan, Y. Pan, A. Pathak, Y. P. Pei, M. Pelizaeus, G. L. Peng, H. P. Peng, X. J. Peng, Y. Y. Peng, K. Peters, K. Petridis, J. L. Ping, R. G. Ping, S. Plura, V. Prasad, L. Pöpping, F. Z. Qi, H. R. Qi, M. Qi, S. Qian, W. B. Qian, C. F. Qiao, J. H. Qiao, J. J. Qin, J. L. Qin, L. Q. Qin, L. Y. Qin, P. B. Qin, X. P. Qin, X. S. Qin, Z. H. Qin, J. F. Qiu, Z. H. Qu, J. Rademacker, C. F. Redmer, A. Rivetti, M. Rolo, G. Rong, S. S. Rong, F. Rosini, Ch. Rosner, M. Q. Ruan, N. Salone, A. Sarantsev, Y. Schelhaas, M. Schernau, K. Schoenning, M. Scodeggio, W. Shan, X. Y. Shan, Z. J. Shang, J. F. Shangguan, L. G. Shao, M. Shao, C. P. Shen, H. F. Shen, W. H. Shen, X. Y. Shen, B. A. Shi, Ch. Y. Shi, H. Shi, J. L. Shi, J. Y. Shi, M. H. Shi, S. Y. Shi, X. Shi, H. L. Song, J. J. Song, M. H. Song, T. Z. Song, W. M. Song, Y. X. Song, Zirong Song, S. Sosio, S. Spataro, S. Stansilaus, F. Stieler, M. Stolte, S. S Su, G. B. Sun, G. X. Sun, H. Sun, H. K. Sun, J. F. Sun, K. Sun, L. Sun, R. Sun, S. S. Sun, T. Sun, W. Y. Sun, Y. C. Sun, Y. H. Sun, Y. J. Sun, Y. Z. Sun, Z. Q. Sun, Z. T. Sun, H. Tabaharizato, C. J. Tang, G. Y. Tang, J. Tang, J. J. Tang, L. F. Tang, Y. A. Tang, Z. H. Tang, L. Y. Tao, M. Tat, J. X. Teng, J. Y. Tian, W. H. Tian, Y. Tian, Z. F. Tian, I. Uman, E. van der Smagt, B. Wang, Bin Wang, Bo Wang, C. Wang, Chao Wang, Cong Wang, D. Y. Wang, H. J. Wang, H. R. Wang, J. Wang, J. J. Wang, J. P. Wang, K. Wang, L. L. Wang, L. W. Wang, M. Wang, Mi Wang, N. Y. Wang, S. Wang, Shun Wang, T. Wang, T. J. Wang, W. Wang, W. P. Wang, X. F. Wang, X. L. Wang, X. N. Wang, Xin Wang, Y. Wang, Y. D. Wang, Y. F. Wang, Y. H. Wang, Y. J. Wang, Y. L. Wang, Y. N. Wang, Yanning Wang, Yaqian Wang, Yi Wang, Yuan Wang, Z. Wang, Z. L. Wang, Z. Q. Wang, Z. Y. Wang, Zhi Wang, Ziyi Wang, D. Wei, D. H. Wei, D. J. Wei, H. R. Wei, F. Weidner, H. R. Wen, S. P. Wen, U. Wiedner, G. Wilkinson, M. Wolke, J. F. Wu, L. H. Wu, L. J. Wu, Lianjie Wu, S. G. Wu, S. M. Wu, X. W. Wu, Z. Wu, H. L. Xia, L. Xia, B. H. Xiang, D. Xiao, G. Y. Xiao, H. Xiao, Y. L. Xiao, Z. J. Xiao, C. Xie, K. J. Xie, Y. Xie, Y. G. Xie, Y. H. Xie, Z. P. Xie, T. Y. Xing, D. B. Xiong, C. J. Xu, G. F. Xu, H. Y. Xu, Q. J. Xu, Q. N. Xu, T. D. Xu, X. P. Xu, Y. Xu, Y. C. Xu, Z. S. Xu, F. Yan, L. Yan, W. B. Yan, W. C. Yan, W. H. Yan, W. P. Yan, X. Q. Yan, Y. Y. Yan, H. J. Yang, H. L. Yang, H. X. Yang, J. H. Yang, R. J. Yang, X. Y. Yang, Y. Yang, Y. H. Yang, Y. M. Yang, Y. Q. Yang, Y. Z. Yang, Youhua Yang, Z. Y. Yang, Z. P. Yao, M. Ye, M. H. Ye, Z. J. Ye, Junhao Yin, Z. Y. You, B. X. Yu, C. X. Yu, G. Yu, J. S. Yu, L. W. Yu, T. Yu, X. D. Yu, Y. C. Yu, Yongchao Yu, C. Z. Yuan, H. Yuan, J. Yuan, Jie Yuan, L. Yuan, M. K. Yuan, S. H. Yuan, Y. Yuan, C. X. Yue, Ying Yue, A. A. Zafar, F. R. Zeng, S. H. Zeng, X. Zeng, Y. J. Zeng, Yujie Zeng, Y. C. Zhai, Y. H. Zhan, B. L. Zhang, B. X. Zhang, D. H. Zhang, G. Y. Zhang, Gengyuan Zhang, H. Zhang, H. C. Zhang, H. H. Zhang, H. Q. Zhang, H. R. Zhang, H. Y. Zhang, Han Zhang, J. Zhang, J. J. Zhang, J. L. Zhang, J. Q. Zhang, J. S. Zhang, J. W. Zhang, J. X. Zhang, J. Y. Zhang, J. Z. Zhang, Jianyu Zhang, Jin Zhang, Jiyuan Zhang, L. M. Zhang, Lei Zhang, N. Zhang, P. Zhang, Q. Zhang, Q. Y. Zhang, Q. Z. Zhang, R. Y. Zhang, S. H. Zhang, S. N. Zhang, Shulei Zhang, X. M. Zhang, X. Y. Zhang, Y. Zhang, Y. T. Zhang, Y. H. Zhang, Y. P. Zhang, Yu Zhang, Z. Zhang, Z. D. Zhang, Z. H. Zhang, Z. L. Zhang, Z. X. Zhang, Z. Y. Zhang, Zh. Zh. Zhang, Zhilong Zhang, Ziyang Zhang, Ziyu Zhang, G. Zhao, J.-P. Zhao, J. Y. Zhao, J. Z. Zhao, L. Zhao, Lei Zhao, M. G. Zhao, R. P. Zhao, S. J. Zhao, Y. B. Zhao, Y. L. Zhao, Y. P. Zhao, Y. X. Zhao, Z. G. Zhao, A. Zhemchugov, B. Zheng, B. M. Zheng, J. P. Zheng, W. J. Zheng, W. Q. Zheng, X. R. Zheng, Y. H. Zheng, B. Zhong, C. Zhong, H. Zhou, J. Q. Zhou, S. Zhou, X. Zhou, X. K. Zhou, X. R. Zhou, X. Y. Zhou, Y. X. Zhou, Y. Z. Zhou, A. N. Zhu, J. Zhu, K. Zhu, K. J. Zhu, K. S. Zhu, L. X. Zhu, Lin Zhu, S. H. Zhu, T. J. Zhu, W. D. Zhu, W. J. Zhu, W. Z. Zhu, Y. C. Zhu, Z. A. Zhu, X. Y. Zhuang, M. Zhuge, J. H. Zou, J. Zu

High Energy Physics (Experiment)

Observation of $\psi(3770)\to p\bar p$ and Measurement of Electromagnetic Form Factors of Proton at $\sqrt{s} = 3.510-4.946$ GeV

BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson et al. (+757 more)

We search for possible charmonium(-like) states decaying into the $p\bar{p}$ final state by studying the Born cross sections of the $e^+e^-\to p\bar{p}$ reaction, and we determine the proton electromagnetic form factors by analyzing the proton angular distribution. The measurement is performed using a sample of $e^+e^-$ collision data collected at 47 center-of-mass energies from 3.510 to 4.946 GeV, corresponding to an integrated luminosity of 26 fb$^{-1}$, recorded by the BESIII detector collected at the BEPCII collider. The decay $\psi(3770)\to p\bar{p}$ is observed with a significance of 6.6$\sigma$ including systematic uncertainties. Furthermore, a structure near 4.2 GeV is observed with significances of $4.6\sigma$ or $4.8\sigma$ for the $\psi(4160)$ or $Y(4230)$ hypotheses including systematic uncertainties, respectively; these interpretations cannot presently be distinguished. In addition, the moduli of the form factor ratios $|G_{E}/G_{M}|$ and of the magnetic form factors $|G_{M}|$ are extracted by analyzing the proton polar angle distribution with higher precision at large time-like squared momentum transfer. These results provide important experimental insights into both the decay mechanisms of charmonium(-like) states in the open charm region and the internal structure of proton.

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Astrophysics of Galaxies

Black Hole Occupation Fraction: Dependence on Black Hole Mass Threshold, Environment, Resolution and Redshift

Emanuele Contini, J.K. Jang, Jinsu Rhee et al. (+2 more)

We take advantage of the state-of-the-art semi-analytic model FEGA25 \citep{contini2025}, run on merger trees extracted from three dark matter-only cosmological simulations, to study the relation between the black hole (BH) occupation fraction, $f_{\rm BH,occ}$, and galaxy stellar mass as a function of BH mass threshold, galaxy type, simulated volume, numerical resolution, sampled galaxy population, and redshift. FEGA25 includes an improved treatment of active galactic nucleus feedback and does not impose a pre-existing BH seed population: BHs grow naturally through quasar and radio modes. Starting from the prerequisite that FEGA25 reproduces the observed BH mass function from at least $z=2$ to the present day, our analysis leads to several results. We find that $f_{\rm BH,occ}$ increases with stellar mass, but that its normalization and shape depend strongly on the adopted BH mass threshold and on the relative contribution of central and satellite galaxies. The relative behavior of central and satellite galaxies depends on the simulation box and BH mass threshold, while the global relation should be interpreted as a population-weighted quantity. We also find significant box-to-box variations, reflecting the combined impact of numerical resolution, simulated volume, and sampled galaxy population. The redshift evolution is not universal: YS50 and the NewCluster zoom-in simulation show a trend qualitatively similar to that reported by \citet{tremmel2024}, whereas larger-volume boxes show the opposite behavior. Finally, comparison with other studies shows that the inferred occupation fraction is highly sensitive to BH mass threshold, simulated volume, numerical resolution, and sampled galaxy population.

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All authors Emanuele Contini, J.K. Jang, Jinsu Rhee, Changjo Seo, Sukyoung K. Yi

Quantum Physics

Wigner-Negative Magnon Steady States from Incoherent Qubit Pumping

Yan Liu and Jiahua Li

We show that incoherently pumped qubits can realize a cascaded dissipative mechanism for stabilizing Wigner-negative magnon steady states. The mechanism combines qubit pumping with dispersive magnon-number selectivity to direct the steady-state population toward selected magnon Fock states. In the single-qubit case, the single-magnon population can approach unity, accompanied by strong antibunching and pronounced Wigner negativity. Extending the same principle to multiple qubits yields Wigner-negative steady states dominated by higher magnon Fock components. We further derive an analytical birth–death model that captures the mechanism and agrees with numerical results. These results establish incoherent qubit pumping as a controllable dissipative resource for generating nonclassical magnon states in hybrid quantum systems.

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Computational Physics · Cross-listed from cs.LG

One-Step Flow Matching for Generative Modeling of Path-Dependent Physical Fields

Yijing Zhou and Jasmin Jelovica

Physical simulations for intricate geometries with path-dependent constitutive models face difficulties due to the enormous computational cost they require. Recently, the emergence of generative AI models, which succeed in image and video synthesis tasks, has provided a promise to further improve simulations. Although U-Net-based denoising diffusion probabilistic models (DDPMs) have been adopted for elastic stress field generation, they typically require hundreds of sampling steps, and applications of generative models to path-dependent, e.g. plastic, stress fields remain very limited. In this work, we propose a novel flow matching (FM) model based on a transformer backbone for high-resolution path-dependent stress field generation with stochastic loading-unloading paths and geometry. The proposed model operates within the latent space of a variational autoencoder (VAE) and formulates the simulation of plastic fields as a video synthesis task, directly generating the stress fields across all time steps. Meanwhile, we design a non-Gaussian source distribution for flow matching, such that crossings among conditional transport paths are reduced during training. This enables our model to generate satisfactory samples in one step without relying on distillation. In addition, we introduce token-level loading embeddings and two auxiliary networks to further enhance the model performance in path-dependent simulation. The results demonstrate that, even with a limited training dataset, our model can accurately generate high-resolution path-dependent fields. It is much more computationally efficient than finite element analysis, providing a speedup of 6 to 7 times over FEM on CPUs and approximately two orders of magnitude speedup on consumer-grade GPUs.

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Nuclear Experiment

Development of a Neural Network-Based Background Suppression Technique for $\Sigma N$ Cusp Spectroscopy at J-PARC

K. Amemiya, Y. Ichikawa, S.H. Hayakawa et al. (+8 more)

A clear spectral enhancement, known as the “$\Sigma N$ cusp”, has been observed near the $\Sigma N$ threshold in the $d(K^-, \pi^-)$ reaction. To understand the dynamical origin of this enhancement, the J-PARC E90 experiment aims to investigate the missing-mass spectrum with an unprecedented resolution of 0.4 MeV ($\sigma$). In this experiment, a Hyperon Time Projection Chamber (HypTPC) is utilized to detect charged decay products and suppress severe contamination from quasi-free (QF) background processes. While a conventional track multiplicity condition of three (Mt=3) effectively suppresses these QF events, it restricts the signal statistics to approximately 17% and introduces a mass-dependent acceptance bias that distorts the spectrum. In contrast, events with a track multiplicity of two (Mt=2) offer roughly double the statistical power ($\sim$39%) with minimal mass dependence, but they suffer from heavy background contamination. To fully exploit the Mt=2 events, we developed an innovative background suppression technique based on a neural network. By constructing a binary classification model using the HypTPC track topology and energy loss ($dE/dx$) as input features, we successfully discriminated the signal from QF backgrounds. This machine learning approach achieves a signal-to-noise ratio comparable to the strict Mt=3 condition while preserving the integrity of the spectral shape. By combining this independent ML-selected Mt=2 sample with the conventional Mt=3 sample, the total usable statistics are effectively doubled compared to traditional methods, significantly enhancing the sensitivity for determining the $\Sigma N$ cusp parameters.

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All authors K. Amemiya, Y. Ichikawa, S.H. Hayakawa, K. Tanida, S.H. Kim, F. Oura, H.I. Lee, R.J. Saito, K. Shimazaki, R. Sasaki, Y. Nakayama

Mesoscale and Nanoscale Physics

Modulating radiative heat and momentum transfer via the thermal Purcell effect

Liyao Jiao, Yaohua Liu and Gaomin Tang

The thermal Purcell effect describes the modification of the local density of states of the fluctuating electromagnetic field induced by a Fabry-Pérot cavity, leading to the enhancement or suppression of radiative transport quantities. Using fluctuational electrodynamics, we investigate nonequilibrium radiative heat, linear-momentum, and angular-momentum exchange between a magneto-optic nanoparticle and a Fabry-Pérot cavity. Analytical expressions for the spectral densities reveal that geometric confinement modifies the electromagnetic local density of states, producing distinct behaviors for different transport quantities. Specifically, sub-wavelength confinement enhances radiative heat and angular-momentum transfer, but suppresses the lateral force. Additionally, interference between cavity modes causes all transfer quantities to oscillate spatially with particle position. At the cavity center, mirror symmetry enforces a parity decomposition of electromagnetic fluctuations resulting in a vanishing lateral force, whereas heat transfer and torque remain finite through combined even and odd modal contributions. These results demonstrate that cavity engineering provides selective control over nanoscale energy and momentum transfer via structured electromagnetic fluctuations.

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Computational Physics · Cross-listed from eess.SY

Development, Validation, and Benchmarking of a Multidisciplinary Semi-Analytical Model for Wave Energy Converters

Rebecca McCabe, Madison Dietrich and Maha Haji

Wave energy converters (WECs) require system-level techno-economic analysis to balance power production, cost, and survivability. Existing simulation tools are either too computationally costly for large-scale optimization or too narrow in disciplinary scope to support integrated design studies. This work presents MDOcean, a novel open-source WEC simulation framework for rapid early-stage design exploration, parametric analysis, and multidisciplinary optimization. MDOcean integrates hydrodynamics, dynamics, structures, and economics in a computationally efficient architecture based on analytical and semi-analytical methods that substantially reduce runtime while maintaining near-numerical accuracy. The framework includes an eigenfunction-based linear hydrodynamic solver, a quasi-linearized frequency-domain dynamics engine capable of modeling drag and saturation nonlinearities, a structural sizing module incorporating realistic yield, ultimate, buckling, storm, and fatigue design criteria, and a simple cost model for techno-economic assessment. Particular emphasis is placed on the linearized pseudo-spectral optimal control formulation, which extends frequency-domain constraint-handling approaches with a unified describing-function and analytical quadratically-constrained quadratic program framework. This formulation efficiently treats nonlinearities and constraints while preserving compatibility with optimization and frequency-domain analysis techniques. Validation and benchmarking demonstrate that MDOcean's 151 ms runtime is orders of magnitude faster than leading WEC simulation tools while maintaining agreement with higher-fidelity baselines to within a few percent in most cases. The framework also provides insight into limiting behaviors, scaling laws, subsystem interactions, and key tradeoffs governing WEC design and techno-economic performance.

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Quantum Physics

All-optical Implementation of Generalized Quantum Teleportation

Takaya Hoshi, Akito Kawasaki, Xiruo Yan et al. (+7 more)

Measurement-based continuous-variable optical quantum computing inherently offers high-speed, large-scale operations, yet its practical performance remains constrained by the processing latencies and throughput bottlenecks imposed by classical electronic feedforward circuits. To overcome these limitations, we propose a loss-tolerant, all-optical feedforward (AOFF) architecture for generalized quantum teleportation, which executes programmable single-mode Gaussian operations and realizes arbitrary single-mode linear operations with two successive stages. Quantitative noise analysis under realistic device parameters demonstrates that the architecture suppresses the hardware-induced noise floor to levels potentially compatible with fault-tolerant quantum computing with Gottesman-Kitaev-Preskill qubits over the range of operations required for their Clifford gates. By eliminating optoelectronic conversions, this scheme enables continuous operations with high analog bandwidth and high temporal-mode throughput that drastically reduce circuit runtime. Ultimately, this approach delivers a noise-resilient platform that reconciles operational versatility with the intrinsic speed and bandwidth of optical quantum information processing.

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All authors Takaya Hoshi, Akito Kawasaki, Xiruo Yan, Atsushi Sakaguchi, Takumi Suzuki, Tatsuki Sonoyama, Hironari Nagayoshi, Kosuke Fukui, Kan Takase, Warit Asavanant

Quantum Physics

A single-electron double quantum dot with Rashba spin-orbit interaction as a working substance for heat machines

Ivan Romualdo de Oliveira, Vinícius N. A. Lula-Rocha and Moises Rojas

We investigate the thermodynamic performance of a quantum Otto machine whose working substance is a single electron confined in a double quantum dot under an external magnetic field and Rashba spin-orbit interaction. The Hamiltonian is controlled by the Zeeman splitting, the interdot tunneling amplitude, and the Rashba coupling, which induces spin-flip tunneling between localized orbital states. Within a quasistatic Otto cycle, we analyze the heat exchanged with the reservoirs, the extracted work, and the efficiency as functions of the Hamiltonian parameters and reservoir temperatures. We show that the Rashba interaction acts as an effective control parameter for switching among heat-engine, refrigerator, heater, and accelerator regimes. A global numerical analysis over the Hamiltonian parameters and reservoir temperatures identifies the optimal operating points for efficiency and work output in the heat-engine regime. The highest efficiencies occur near the maximum temperature gradient explored and approach the Carnot bound, whereas the largest work output appears in a different region of parameter space. The results reveal a clear trade-off between maximum efficiency and maximum extracted work, governed by the spectral deformation induced by the Zeeman splitting, tunneling amplitude, and Rashba coupling.

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Quantum Physics

Protecting Qubits from Purcell Decay via Permanent Dipoles

Alex Krasnok

Reading out a qubit often requires coupling it to a resonator, but that same resonator can also give the qubit an extra path to decay. Here, we study a way to reduce this loss using a built-in permanent electric dipole. The dipole shifts the cavity field in different directions for the qubit ground and excited states. This shift makes the relevant wave functions overlap less, which weakens the transverse qubit–cavity exchange that causes Purcell decay. In a simplified displaced rotating-wave model, this exchange vanishes at $\eta=\sqrt{2}$. In the full transverse model, this exact zero is lifted, but strong suppression remains at a larger dipole-induced displacement. Using dressed open-system decay rates, we find an operating point where the cavity-mediated decay is strongly reduced while the longitudinal readout signal remains finite. For the benchmark studied here, at fixed pointer separation, the normalized lifetime increases from $\kappa T_1=11.1$ to $47.3$, and the estimated single-shot readout error drops from $0.21$ to $0.07$. These results show that permanent electric dipoles can provide an internal, channel-selective form of Purcell protection.

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Sunday 21 June

Mathematical Physics · Cross-listed from math.OC

Noether's Second Theorem and the Pareto Front Structure in Multi-Criteria Variational Problems

Evgeny Nikulchev

This paper establishes a rigorous connection between Noether's second theorem and the structure of Pareto fronts in multi-criteria variational problems. We prove that for a family of functionals invariant under a common gauge Lie group, the regular part of the Pareto front is contained in the union of solutions to weighted Euler–Lagrange equations, and that on Pareto-optimal sections, combinations of Noether currents are conserved. Gauge symmetries are shown to impose additional constraints on the Lagrange multipliers via Bianchi-type identities, reducing the dimension of the admissible weight space. Two practical approaches are derived from this result: dimensionality reduction via gauge fixing and scalarization with penalty terms. The theory is validated on three classical problems: the linear-quadratic regulator with two criteria, a model predictive control problem with a minimax criterion, and the double integrator with control constraints. In each case, the Pareto front is shown to satisfy an exact conservation law, and the analytical structure of the front is recovered from the symmetries of the problem. The results demonstrate that gauge functions (null Lagrangians) can restore invariants even when the dynamics break the symmetry, and that control constraints do not destroy the underlying conservation laws but merely restrict the admissible set. The proposed approach yields a Pareto front with minimal deviation from the theoretical curve, outperforming known multi-objective algorithms, and provides a new foundation for the analytical treatment of multi-criteria optimization in nonlinear dynamics and control.

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Mathematical Physics

The Dirac equation in (split-)octonions: origins, variants, and modern context

J. Köplinger

Octonions and split-octonions have been used to express the Dirac equation in physics in several conceptually distinct ways. This review organizes them into four groups: the 2-factor, 3-factor, and projection representations, which use (split-)octonion basis elements natively to model a spacetime basis, and the conventional use of octonions to carry Dirac algebra acting on spinors. For each group we identify the originating construction, relate later variants to it, and point to modern applications and to recent methods for native split-octonionic analysis. Because the multiplication table of the (split-)octonions is not unique, forms that look different in print can coincide after a norm-preserving linear isometry and a multiplication-preserving change of basis; we make such relations explicit and tabulate the basis conventions used across select sources. The 2-factor representation is treated in most detail: we document its origin and show that a recently proposed split-octonionic Dirac equation coincides with it after such an isometry and change of basis, while crediting the independent contributions of that work.

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Adaptation and Self-Organizing Systems · Cross-listed from cs.NE

Emergent Culture in Minimal LLM Systems

Simon Jones and Sabine Hauert

What happens when LLM agents operate with no context outside a turn, minimal prompting, and simple tools? Inspired by swarm engineering, we give collectives of three agents the ability to send messages and manipulate a shared actively decaying text store, introducing evolutionary pressure. The agents spontaneously cooperate, develop storage management strategies, and generate complex evolving cultural artifacts, with no top-down engineering. Using tools from dynamical systems analysis, we show that these behaviours exhibit structured long-range coherence beyond the entropy horizon of the decaying store, consistent with emergent culture in the Sperberian sense.

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Chaotic Dynamics · Cross-listed from eess.SY

Reconstruction of chaotic systems in invariant jet space

Evgeny Nikulchev

Takens' theorem is the gold standard for attractor reconstruction from time series, but it guarantees only topological equivalence and does not preserve metric or group properties such as symmetries. We show that switching from delay-coordinate space to jet space (signal and its derivatives) allows one to exactly preserve the symmetry group of the original system. This statement is rigorously justified by a theorem on the isomorphism of Lie algebras under jet prolongation. Numerical experiments on the Lorenz and Rössler systems confirm that jet-space reconstruction preserves geometry and symmetries, whereas Takens embedding distorts them. As quantitative metrics we use a variational elastic energy functional and the correlation dimension. It is shown that jet-space reconstruction not only outperforms Takens embedding but in some cases yields more accurate estimates of invariants than projections of the original system. The proposed approach provides a coordinate-invariant criterion for the classification of strange attractors and can serve as a basis for detecting hidden attractors.

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Quantum Physics

Reading Weakly, Acting Strongly: A Static Parity Horizon and its Dynamical Bypass in the Monitored Lipkin-Meshkov-Glick Model

Stavros Mouslopoulos

We study the broken-symmetry phase of the Lipkin-Meshkov-Glick (LMG) model, whose two lowest states form a near-degenerate parity doublet split by tunnelling. We show that the same instanton action S_inst that sets the doublet splitting also controls how much parity information a static J_z magnetisation readout can extract. Although J_z measures magnetisation rather than parity - and so distinguishes the two wells easily while remaining almost blind to their relative sign - WKB barrier arguments together with exact diagonalisation show that the spectral gap, the total-variation distance, and the nonlinear distinguishability measures (Jensen-Shannon divergence and Chernoff information) share a single instanton exponent, rather than the doubled exponent a naive small-deviation expansion in the lobes would suggest. Exact diagonalisation up to N = 4500 supports a common leading exponent for all four quantities, with fitted values within a few percent of the WKB instanton value in the largest reliable windows. The same coupling acts strongly inside the doublet: its off-diagonal element grows as |J_01| -> N m_*/2, so the bath can disturb the parity label far more strongly than it can read it from a frozen histogram. We call this separation the static parity horizon - a benchmark for the idealised static J_z channel, not a universal bound on time-resolved monitoring. Restoring the full monitored dynamics, continuous-monitoring simulations (1.48 million full-LMG trajectories with matched QND controls across 77 independent settings) show that a time-resolved homodyne record extracts parity information hidden from the single-shot histogram, over a finite window of system sizes organised by the ratio xi = omega_01/Gamma_01 of coherent doublet rotation to measurement-induced dephasing, and closing again under strong measurement.

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Statistical Mechanics

Microscopic Nonreciprocity-Governed Topological Boundary Flows in Active Matter

Tong Zhu and Zhigang Zheng

We connect microscopic nonreciprocity to chiral boundary transport in a minimal frustrated Vicsek–Kuramoto model. Unlike field-level constructions, a low-angular-harmonic closure of particle dynamics yields the non-Hermitian operator. Direction-independent polar projector limits permit wave-number compactification, and the Sakaguchi phase lag reverses the polar spin weights, producing $C=\pm2$ where the closure is nonsingular and the projector remains globally isolated. Strip edge-mode propagation agrees with particle circulation. Crucially, chirality and defect tolerance are distinct: before pattern onset, boundary streams retain chirality on regular convex boundaries but are vulnerable to strong isolated defects; an interior vortex lattice supports a counterpropagating edge stream with substantially stronger defect tolerance in the tested geometries. Thus spectral topology selects a chiral boundary branch, while pattern formation supports its robust nonlinear realization.

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Exactly Solvable and Integrable Systems

Invariants for a family of discrete equations with the Laurent property

Andrei K Svinin

Recently, we have found an infinite family of homogeneous discrete equations of odd order possessing the Laurent property. The first representative of this family is the well-known Somos-5 equation, which under certain conditions generates the integer sequence A006721, which has numerous applications. In this work, we construct a finite set of independent invariants for our equations. We show, through examples, that the presence of these invariants allows us to find a more general criterion for the integrality of sequences compared to what the usual Laurent property provides.

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High Energy Physics (Phenomenology)

axionbloch: an Open-Source Python Package for Simulating Axion-Induced Spin Dynamics

Yuzhe Zhang

The interaction of ultralight bosonic dark matter with spins can be interpreted as a pseudomagnetic field acting on normal matter. Such interactions can be modeled as usual magnetic interactions using spin-evolution (Bloch) equations. axionbloch, an open-source Python package for simulating spin dynamics induced by both usual and exotic interactions, is presented. The numerical simulations serve as a tool for deriving axion signal signatures, which are crucial for designing experimental searches and data analysis. Simulations are calibrated against theoretical expectations, ensuring the accuracy of the simulated signals. axionbloch is available at https://github.com/Yuzhe98/AxionBloch, allowing researchers to simulate pseudomagnetic signals under specific configurations of the axion models and experimental setups. The package is documented at http://axionbloch.readthedocs.io/ and includes example scripts for application.

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General Relativity and Quantum Cosmology

Physical properties of charged black holes from the nonlinear electrodynamics model based on electric potential regularization

S. Habib Mazharimousavi

We investigate static, spherically symmetric black hole solutions arising from Einstein gravity minimally coupled to a nonlinear electrodynamics (NED) model constructed from a regularized electric potential of a point charge. The resulting spacetime is characterized by three parameters, namely, the ADM mass $% M $, the electric charge $Q$, and the nonlinear scale $r_{0}$. We show that, depending on the values of $M$ and $Q$, the solutions exhibit a rich causal structure comprising black holes with single, double, and triple horizons, as well as naked singular geometries. The nature of the central singularity is determined by the combination $m-\frac{2}{3}q^{2}$, allowing for both spacelike and timelike singularities. We perform a detailed thermodynamic analysis by deriving the Hawking temperature and heat capacity, revealing the existence of two critical charge parameters that govern the thermal behavior. Below a critical charge, the black holes are thermally unstable, whereas above it a stable phase emerges within a finite range of horizon radii bounded by Davies points. For sufficiently large charge, extremal configurations with vanishing temperature arise, further constraining the stability region. We also investigate observational signatures by analyzing null geodesics and black hole shadows, showing that nonlinear electrodynamics corrections lead to noticeable deviations from the Reissner-Nordström geometry, including the possible absence of a photon sphere beyond a critical charge. Our results highlight that nonlinear electrodynamics significantly enriches the causal structure, thermodynamic phase space, and dynamical response of charged black holes, providing potentially observable deviations from the Reissner-Nordström paradigm.

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Materials Science

Notes on remanent magnetization measurements in superconductors and hard ferromagnets

Sergey L. Bud'ko, Mingyu Xu, Weiwei Xie et al. (+3 more)

Data on zero applied field measurements of remanent magnetization and magnetic relaxation in a BCS superconductor LuNi2B2C and several hard ferromagnets are presented and compared. Apparent similarities and differences, in particular in Thermoremanent Magnetization (TRM) - like, Isothermal Remanent Magnetization (IRM) - like, and remanent magnetization measurements with zigzag temperature sweep measurements are outlined. It is discussed how these results could be relevant for the magnetization measurements in diamond anvil cells.

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All authors Sergey L. Bud'ko, Mingyu Xu, Weiwei Xie, Chaowei Hu, Ni Ni, Paul C. Canfield

High Energy Physics (Phenomenology)

From Magnetic to Inverse Magnetic Catalysis: The Interplay of Quark and Gluon Mass Generation in Magnetic Fields

Fei Gao, Kairen Huang, Yi Lu et al. (+1 more)

We analyze the effects of the magnetic field on the quark and gluon propagators within the functional QCD framework. By solving the coupled Dyson-Schwinger equations for the quark and gluon propagators, we find that the quark mass is generally enhanced in the presence of a magnetic field, leading to magnetic catalysis of the chiral condensate. Meanwhile, the magnetic field also induces an increase in the gluon screening mass. The enhancement of the gluon screening mass suppresses the quark-gluon interaction and thereby weakens the strength of dynamical chiral symmetry breaking, establishing a competing mechanism against magnetic catalysis. In particular, this enhancement of the gluon screening mass becomes dominant near the chiral phase transition, which in turn gives rise to inverse magnetic catalysis.

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All authors Fei Gao, Kairen Huang, Yi Lu, Yuxin Liu