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θ dependence of T_c in SU(2) Yang-Mills theory

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Journal of High Energy physics 2025年第2期2025卷 1-18页

作者： Yamada, Norikazu Yamazaki, Masahito Kitano, Ryuichiro Theory Center Institute of Particle and Nuclear Studies High Energy Accelerator Research Organization (KEK) Tsukuba 305-0801 Japan Graduate University for Advanced Studies (SOKENDAI) Tsukuba 305-0801 Japan Department of Physics University of Tokyo Tokyo 113-0033 Japan Kavli Institute for the Physics and Mathematics of the Universe University of Tokyo Chiba 277-8583 Japan Trans-Scale Quantum Science Institute University of Tokyo Tokyo 113-0033 Japan Center for Data-Driven Discovery Kavli IPMU University of Tokyo Chiba 277-8583 Japan

We present an exploratory study to determine the confinement-deconfinement transition temperature at finite θ, Tc(θ), for the 4d SU(2) pure Yang-Mills theory. Lattice numerical simulations are performed on three spa... 详细信息

We present an exploratory study to determine the confinement-deconfinement transition temperature at finite θ, T_c(θ), for the 4d SU(2) pure Yang-Mills theory. Lattice numerical simulations are performed on three spatial sizes N_S = 24, 32, 48 with a fixed temporal size N_T = 8. We introduce a non-zero θ-angle by the sub-volume method to mitigate the sign problem. By taking advantage of the universality in the second order phase transition and the Binder cumulant of the order parameter, the θ-dependence of T_c is determined to be T_c(θ)/T_c(0) = 1 − 0.16(2) (θ/π)² − 0.03(4) (θ/π)⁴ up to θ ∼ 0.9 π. The reliability of the extrapolations in the sub-volume method is extensively checked. We also point out that the temperature dependence of the topological susceptibility should exhibit a singularity with the exponent for the specific heat. © The Author(s) 2025.

关键词： Lattice QCD Non-Zero Temperature and Density Phase Transitions

Black Hole Complementarity and ER/EPR

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arXiv 2025年

作者： Bao, Ning Remmen, Grant N. Department of Physics Northeastern University BostonMA02115 United States Computational Science Initiative Brookhaven National Laboratory UptonNY11973 United States Center for Cosmology and Particle Physics Department of Physics New York University New YorkNY10003 United States

We demonstrate that wormholes must be entangled regardless of asymptotic boundary conditions. Assuming black hole complementarity, we argue that traversable wormholes instantiate entanglement-assisted quantum channels and that this entanglement must be present between the stretched horizons as an initial condition prior to traversability. This result demonstrates the forward direction of the ER/EPR conjectures. © 2025, CC BY.

关键词： Quantum channel

Atmospheric Antideuteron Flux Within a Dynamical Coalescence Approach

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arXiv 2025年

作者： Pu, Jie Li, Xin Sun, Kai-Jia Ma, Chun-Wang Chen, Lie-Wen College of Physics Henan Normal University Xinxiang453007 China Institute of Nuclear Science and Technology Henan Academy of Science Zhengzhou450046 China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan University Shanghai200438 China School of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmology Key Laboratory for Particle Astrophysics and Cosmology MOE Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of Nuclear Physics and Ion-Beam Application MOE Institute of Modern Physics Fudan University Shanghai200433 China

Cosmic antideuterons are considered as one of the most promising tools for the indirect detection of dark matter due to their ultra-low astrophysical backgrounds. Currently only upper limits on the antideuteron flux exist, but advancements in experimental detection technology may soon lead to positive signals. A major source of background is the production of secondary antideuterons through collisions of cosmic rays with the surrounding medium. In this study, antideuteron production is modeled using a multiphase transport model (AMPT) coupled with a dynamical coalescence model. By applying a widely used leaky box model and incorporating specific processes, we present a new theoretical baseline for atmospheric secondary antideuteron flux, including a tertiary contribution, from primary cosmic rays interacting with Earth’s atmosphere. Our results indicate that the atmospheric antideuteron flux are within the range of various existing calculations and remain well below the upper limits set by the Balloon-borne Experiment with a Superconducting Spectrometer (BESS). The atomospheric antideuteron is found to dominate the antideuteron background at kinetic energies below 0.26 GeV/n. © 2025, CC BY.

关键词： Kinetic energy

Formation of defects associated with both spontaneous and explicit symmetry breaking

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Physical Review D 2025年第2期111卷 023511-023511页

作者： Kohei Fujikura Mairi Sakellariadou Michiru Uwabo-Niibo Masahide Yamaguchi Graduate School of Arts and Sciences University of Tokyo Komaba Meguro-ku Tokyo 153-8902 Japan Theoretical Particle Physics and Cosmology Group Physics Department King’s College London University of London Strand London WC2R 2LS United Kingdom Department of Physics Graduate School of Humanities and Sciences Ochanomizu University Tokyo 112-8610 Japan Cosmology Gravity and Astroparticle Physics Group Center for Theoretical Physics of the Universe Institute for Basic Science (IBS) Daejeon 34126 Korea Department of Physics Institute of Science Tokyo Tokyo 152-8551 Japan

We discuss formation of cosmic strings associated with a spontaneously broken approximate U(1) symmetry by performing classical field-theoretical simulations. An original U(1) symmetry is explicitly broken down to its subgroup ZN even before spontaneous breaking takes place. We estimate the ratio of explicit breaking to that of spontaneous breaking for which topological defects for N=1 and N=2 are formed. For N=1, a cosmic string attached to a single domain wall can be formed when the amount of the explicit breaking is 3 orders of magnitude smaller than that of the spontaneous breaking. For N=2, no matter how large the explicit breaking is, domain walls are inevitably formed as long as the temperature of the Universe is high enough to restore Z2 symmetry. In that case, cosmic strings are also inevitably formed as long as the amount of the explicit breaking is smaller than that of the spontaneous breaking.

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Singular instantons with finite action

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arXiv 2025年

作者： Sasaki, Misao Yingcharoenrat, Vicharit Zhang, Ying-Li School of Physics Science and Engineering Tongji University Shanghai200092 China Institute for Advanced Study of Tongji University Shanghai200092 China UTIAS The University of Tokyo Chiba277-8583 Japan Center for Gravitational Physics and Quantum Information Yukawa Institute for Theoretical Physics Kyoto University Kyoto606-8502 Japan Leung Center for Cosmology and Particle Astrophysics National Taiwan University Taipei10617 Taiwan High Energy Physics Research Unit Department of Physics Faculty of Science Chulalongkorn University Pathumwan Bangkok10330 Thailand Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China Center for Gravitation and Cosmology Yangzhou University Yangzhou225009 China

Recently, it was shown that in the absence of gravity there exist non-O(4)-symmetric instanton solutions with finite action beyond Coleman’s instantons. In this paper, focusing on the false-vacuum decay in a single scalar field in flat Euclidean space, we provide a general discussion on O(4)-symmetric instantons that are singular at the true-vacuum bubble. We find that, for the action to remain finite without introducing a UV cutoff, the potential must be unbounded from below and take the exponential form, thereby evading Coleman’s theorem. We then consider two explicit examples of such instantons and perturbatively analyze the dynamics of small deformations around them. We find that one of them does not allow regular deformations, which indicates that the O(4) symmetric solution still gives the minimum action, while the other one is found to allow regular deformations that cost no additional action at second order in perturbation. The latter example opens up the possibility of the existence of non-O(4)-symmetric solutions with lower action if we allow singular instantons with finite action. © 2025, CC BY.

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SHAM-OT: Rapid Subhalo Abundance Matching with Optimal Transport

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arXiv 2025年

作者： Fischbacher, Silvan Kacprzak, Tomasz Valle, Luis Fernando Machado Poletti Refregier, Alexandre Institute for Particle Physics and Astrophysics ETH Zürich Wolfgang-Pauli-Strasse 27 ZürichCH-8093 Switzerland Swiss Data Science Center Paul Scherrer Institute Forschungsstrasse 111 Villigen5232 Switzerland

Subhalo abundance matching (SHAM) is widely used for connecting galaxies to dark matter haloes. In SHAM, galaxies and (sub-)haloes are sorted according to their mass (or mass proxy) and matched by their rank order. In this work, we show that SHAM is the solution of the optimal transport (OT) problem on empirical distributions (samples or catalogues) for any metric transport cost function. In the limit of large number of samples, it converges to the solution of the OT problem between continuous distributions. We propose SHAM-OT: a formulation of abundance matching where the halo-galaxy relation is obtained as the optimal transport plan between galaxy and halo mass functions. By working directly on these (discretized) functions, SHAM-OT eliminates the need for sampling or sorting and is solved using efficient OT algorithms at negligible compute and memory cost. Scatter in the galaxy-halo relation can be naturally incorporated through regularization of the transport plan. SHAM-OT can easily be generalized to multiple marginal distributions. We validate our method using analytical tests with varying cosmology and luminosity function parameters, and on simulated halo catalogues. The efficiency of SHAM-OT makes it particularly advantageous for Bayesian inference that requires marginalization over stellar mass or luminosity function uncertainties. © 2025, CC BY.

关键词： Cost functions

Dynamics of Bronnikov-Ellis wormhole with double-null simulation

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arXiv 2025年

作者： Xu, Anyuan Chew, Xiao Yan Yeom, Dong-Han School of Science Jiangsu University of Science and Technology Zhenjiang212100 China Department of Physics Education Pusan National University Busan46241 Korea Republic of Research Center for Dielectric and Advanced Matter Physics Pusan National University Busan46241 Korea Republic of Leung Center for Cosmology and Particle Astrophysics National Taiwan University Taipei10617 Taiwan Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada

We investigate the dynamical collapse of Bronnikov-Ellis (BE) wormhole using the double-null formalism, where its throat is characterized by the coincidence of two curves r,u = 0 and r,v = 0. The emission of two ingoing pulses: normal scalar and phantom fields in the wormhole spacetime reveals two distinct instability scenarios: a normal scalar field triggers gravitational collapse into a black hole where the singularity r = 0 hidden by the event horizon (r,u = 0 and r,v = 0);while a phantom field drives inflationary expansion of wormhole, decoupling two asymptotic regions with the cosmological horizon (r,u = 0 and r,v = 0). The process of two scenarios can be accelerated by increasing the amplitude of pulses but can be delayed by increasing the wormhole’s mass. Additionally, the collisions of two identical pulses from ingoing and outgoing null directions in the massless BE wormhole fail to cure the instabilities because the two scenarios can still occur, but the formation of a black hole can be delayed for the collision of normal and phantom fields. Interestingly, the strategic tuning of emission timing for outgoing phantom field to collide with ingoing normal scalar field can temporarily stabilize the wormhole throat by restoring the coincidence of r,u and r,v again after their separation. This offers us valuable insights into extending the lifetime of a traversable wormhole. © 2025, CC BY.

关键词： Black holes

Development of a Neutron Imager using CMOS Pixelated Sensor

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arXiv 2025年

作者： Kamiya, Yoshio Ohshita, Hidetoshi Nishimura, Ryutaro Muto, Toshiya Mitsui, Shingo Seya, Tomohiro Umegaki, Izumi Arai, Yasuo Department of Physics International Center for Elementary Particle Physics The University of Tokyo Tokyo113-0033 Japan Ibaraki305-0801 Japan Kanagawa240-0193 Japan Tohoku University Miyagi982-0826 Japan Data Science and AI Innovation Research Promotion Center Shiga University Shiga522-8522 Japan Ibaraki305-0801 Japan

We acquired an image of the Siemens Star Chart using the 10B-INTPIX4 CMOS pixelated imager at J-PARC MLF BL21 (NOVA). The image blurriness, characterized by a root mean square (rms) value of 17 µm in the line spread function, corresponds to an rms beam divergence of 2.7 mrad. for the neutron beam. This is equivalent to the L/D ratio of 370. The contrast of the image was analyzed as a function of structural scale of the chart, and based on this contrast, the modulation transfer function (MTF) of the imaging system was evaluated. The results indicate that the structure corresponding to the 50% cutoff is 12 line-space pairs per mm. © 2025, CC BY-NC-ND.

关键词： CMOS integrated circuits

Molecular Cloud Biology

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arXiv 2025年

作者： Feng, Lei Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing210023 China School of Astronomy and Space Science University of Science and Technology of China Anhui Hefei230026 China Joint Center for Particle Nuclear Physics and Cosmology Nanjing University Purple Mountain Observatory Nanjing210093 China

Some astrobiological models suggest that molecular clouds may serve as habitats for extraterrestrial life. This study reviews recent theoretical work addressing the physical and biochemical prerequisites for life in such environments, with particular focus on three subjects: (1) bioenergetic pathways under extreme low-temperature conditions;(2) the emergence and preservation of biomolecular chirality;and (3) detection methodologies for potential biosignatures. In this paper, we formally introduce the molecular cloud biology concept, which integrates all physicochemical and metabolic processes hypothesized to sustain life within molecular clouds. As a potential branch of astrobiology, molecular cloud biology warrants interdisciplinary collaborative research to validate its foundational assumptions and explore its scientific implications. Copyright © 2025, The Authors. All rights reserved.

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