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Distinguishing the observational signatures of hot spots orbiting Reissner-Nordström spacetime

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Chinese physics C 2024年第7期48卷 221-230页

作者：吴天枢陈一千 center for theoretical physics College of PhysicsSichuan UniversityChengdu 610064China

This paper investigates observable signatures of hot spots orbiting Reissner-Nordström(RN)black holes and naked *** an RN black hole,we find two discernible lensing image tracks in time integrated images,capturing a complete orbit of hot spots and a image shadow within the critical curve where photons with a small impact parameter fall into the event ***,in RN singularities,additional image tracks can be found within the critical curve,originating from photons reflected by the infinitely high effective potential ***,we find incomplete and converging tracks from the time integrated images of hot spot orbiting RN singularities that have no photon *** presence of these additional image tracks significantly influences temporal magnitudes at their local maxima,enabling us to differentiate between RN black holes and RN naked singularities.

关键词： astrometry gravitational lensing black hole physics D0I:10.1088/1674-1137/ad3c2d

Thermodynamic nature of black holes in coexistence region

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Science China(physics,Mechanics & Astronomy) 2024年第5期67卷 27-32页

作者： Shao-Wen Wei Yu-Xiao Liu Lanzhou center for theoretical physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of Mo ELanzhou UniversityLanzhou 730000China Institute of theoretical physics&Research center of Gravitation Lanzhou UniversityLanzhou 730000China

Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic ***,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of *** at these coexistence states,in this work,we develop a general approach by introducing two new ratio *** first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule *** demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase *** study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and *** results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.

关键词： transition. state. thermodynamic

Symbology of Feynman integrals from twistor geometries

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Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 44-59页

作者： Song He Jiahao Liu Yichao Tang Qinglin Yang School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China international Centre for theoretical physics Asia-Pacific Beijing 100049 Peng Huanwu center for Fundamental Theory Hefei 230026China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). Cutting propagators in momentum twistor space amounts to intersecting lines associated with loop and external dual momenta, including the special line associated with the point at infinity, which breaks dual conformal symmetry. We show that cross-ratios of intersection points on these lines, especially those on the infinity line, naturally produce symbol letters for Feynman integrals in D = 4-2∈, which include and generalize their LS. At one loop, we obtain all symbol letters using intersection points from quadruple cuts for integrals up to pentagon kinematics with two massive corners, which agree perfectly with canonical differential equation(CDE) results. We then obtain all two-loop letters, for up to four-mass box and one-mass pentagon kinematics, by considering more intersections arising from two-loop cuts. Finally we comment on how cluster algebras appear from this construction, and importantly how we may extend the method to non-planar integrals.

关键词： Feynman integrals symbol letters twistor geometry

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-Chun Zhang Hai-Zhou Lu X.C.Xie Kavli Institute for theoretical Sciences University of Chinese Academy of Sciences Department of physics Southern University of Science and Technology (SUSTech) international center for Quantum Materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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Color-kinematics duality and dual conformal symmetry for a four-loop form factor in N=4 SYM

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Science China(physics,Mechanics & Astronomy) 2024年第4期67卷 64-71页

作者： Guanda Lin Gang Yang Siyuan Zhang CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China international Centre for theoretical physics Asia-Pacific Beijing/Hangzhou 310024China

We obtain the integrand of full-color four-loop three-point form factor of the stress-tensor supermultiplet in N=4 SYM,based on the color-kinematics(CK)duality and generalized unitarity *** result not only manifests all dual Jacobi relations via CK duality but also contains 133 free *** suggests the constructibility of the form factor at even higher loops via CK *** also find that the planar form factor has a hidden dual conformal symmetry in the lightlike limit of the operator momentum,which is checked up to four loops.

关键词： S-matrix supersymmetric model perturbative calculations

Masses and decays of triply-heavy pentaquarks

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Chinese physics C 2024年第10期48卷 137-149页

作者： Chang-Le Liu Wen-Xuan Zhang Duo-Jie Jia Institute of theoretical physics College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070China General Education center Qinghai Institute of TechnologyXining 810000China Lanzhou center for theoretical physics Lanzhou UniversityLanzhou 730000China

In this study,we analyzed masses and decays of triply-heavy pentaquarks QQQnn(Q=b,c)in the unified MIT bag *** construct the color-spin wave functions of the triply-heavy pentaquarks and use the numerical variational method to compute all the ground-state masses of these *** excluding the scattering states in configuration spsce,we computed the decay width ratios of each decay channel relative to the maximum width for the compact pentaquark states,obtaining the main decay modes of the triply-heavy pentaquark systems.

关键词： pentaquark mass decay channels

Slowly rotating charges from Weyl double copy for Kerr black hole with Chern-Simons correction

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Communications in theoretical physics 2024年第8期76卷 139-146页

作者： Yi-Ran Liu Jing-Rui Zhang Yun-Long Zhang School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100149China National Astronomy Observatories Chinese Academy of ScienceBeijing 100101China international center for theoretical physics Asia-Pacific Beijing/HangzhouChina

The Weyl double copy builds the relation between gauge theory and gravity theory, in particular the correspondence between gauge solutions and gravity solutions. In this paper, we obtain the slowly rotating charge solutions from the Weyl double copy for the Kerr black hole with small Chern-Simons correction. Based on the Weyl double copy relation, for the Petrov type D solution in Chern-Simons modified gravity, we find the additional correction to the electromagnetic field strength tensor of the rotating charge. For the Petrov type I solution, we find that the additional electromagnetic field strength tensors have external sources, while the total sources vanish at the leading order.

关键词： Chern-Simons modified gravity Weyl double copy Kerr black hole

Supermassive black holes triggered by QCD axion bubbles

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Communications in theoretical physics 2024年第5期76卷 134-139页

作者： Hai-Jun Li Ying-Quan Peng Wei Chao Yu-Feng Zhou Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China international Centre for theoretical physics Asia-Pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still *** this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion *** this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after *** QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase *** consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))*** PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

Symmetry transformation of nonlinear optical current of tilted Weyl nodes and application to ferromagnetic MnBi_(2)Te_(4)

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Chinese physics B 2024年第4期33卷 160-171页

作者：卢倬成冯济 international center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China

A Weyl node is characterized by its chirality and *** develop a theory of how nth-order nonlinear optical conductivity behaves under transformations of anisotropic tensor and tilt, which clarifies how chirality-dependent and-independent parts of optical conductivity transform under the reversal of tilt and *** on this theory, we propose ferromagnetic Mn Bi2Te4as a magnetoelectrically regulated, terahertz optical device, by magnetoelectrically switching the chiralitydependent and-independent DC *** results are useful for creating nonlinear optical devices based on the topological Weyl semimetals.

关键词： nonlinear optical response topological Weyl semimetals chiral anomaly