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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 141-148页

作者： Yi-Ran Liu Jing-Rui Zhang Yun-Long Zhang School of Fundamental physics and Mathematical sciences Hangzhou Institute for Advanced StudyUCAS CAS Key Laboratory of theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences University of Chinese academy of sciences national Astronomy Observatories Chinese Academy of Science International Center for theoretical physics Asia-Pacific

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 Kerr black hole Weyl double copy

Classification of high-ordered topological nodes towards Moiré flat bands in twisted bilayers

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Science China(physics,Mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 137-151页

作者： Fan Cui Congcong Le Qiang Zhang Xianxin Wu Jiangping Hu Ching-Kai Chiu Beijing national Laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of Sciences School of Physical sciences University of Chinese Academy of Sciences RIKEN Interdisciplinary theoretical and Mathematical sciences(iTHEMS) CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of Sciences Kavli institute of theoretical sciences University of Chinese Academy of Sciences New Cornerstone Science Laboratory

At magic twisted angles, Dirac cones in twisted bilayer graphene(TBG) can evolve into flat bands, serving as a critical playground for the study of strongly correlated physics. When chiral symmetry is introduced, rigorous mathematical proof confirms that the flat bands are locked at zero energy in the entire Moiré Brillouin zone(BZ). Yet, TBG is not the sole platform that exhibits this absolute band flatness. Central to this flatness phenomenon are topological nodes and their specific locations in the BZ. In this study, considering twisted bilayer systems that preserve chiral symmetry, we classify various ordered topological nodes in base layers and all possible node locations across different BZs. Specifically, we constrain the node locations to rotational centers,such as Γ and M points, to ensure the interlayer coupling retains equal strength in all directions. Using this classification as a foundation, we systematically identify the conditions under which Moiré flat bands emerge. Additionally, through the extension of holomorphic functions, we provide proof that flat bands are locked at zero energy, shedding light on the origin of the band flatness. Remarkably, beyond Dirac cones, numerous twisted bilayer nodal platforms can host flat bands with a degeneracy number of more than two, such as four-fold, six-fold, and eight-fold. This multiplicity of degeneracy in flat bands might unveil more complex and enriched correlation physics.

关键词： twisted bilayer systems high-ordered topological nodes Morié flat bands high degeneracy

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K-core attack, equilibrium K-core,and kinetically constrained spin system

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Chinese physics B 2024年第6期33卷 14-26页

作者：周海军 institute of theoretical physics Chinese Academy of SciencesBeijing 100190China MinJiang Collaborative Center for theoretical physics MinJiang UniversityFuzhou 350108China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China

Kinetically constrained spin systems are toy models of supercooled liquids and amorphous solids. In this perspective,we revisit the prototypical Fredrickson–Andersen(FA) kinetically constrained model from the viewpoint of K-core combinatorial optimization. Each kinetic cluster of the FA system, containing all the mutually visitable microscopic occupation configurations, is exactly the solution space of a specific instance of the K-core attack problem. The whole set of different jammed occupation patterns of the FA system is the configuration space of an equilibrium K-core problem. Based on recent theoretical results achieved on the K-core attack and equilibrium K-core problems, we discuss the thermodynamic spin glass phase transitions and the maximum occupation density of the fully unfrozen FA kinetic cluster, and the minimum occupation density and extreme vulnerability of the partially frozen(jammed) kinetic clusters. The equivalence between K-core attack and the fully unfrozen FA kinetic cluster also implies a new way of sampling K-core attack solutions.

关键词： Fredrickson–Andersen model K-core attack spin glass jamming

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

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A family of quantum von Neumann architecture

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Chinese physics B 2024年第8期33卷 56-61页

作者：王东升 CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

We develop universal quantum computing models that form a family of quantum von Neumann architectures,with modular units of memory,control,CPU,and internet,besides input and *** family contains three generations characterized by dynamical quantum resource theory,and it also circumvents no-go theorems on quantum programming and *** universality,such a family satisfies other desirable engineering requirements on system and algorithm design,such as modularity and programmability,hence serves as a unique approach to building universal quantum computers.

关键词： von Neumann architecture quantum resource theory quantum computing

Energy-information trade-off induces continuous and discontinuous phase transitions in lateral predictive coding

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Science China(physics,Mechanics & Astronomy) 2024年第6期67卷 79-85页

作者： Zhen-Ye Huang Ruyi Zhou Miao Huang Hai-Jun Zhou Key Laboratory for theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical sciences University of Chinese Academy of SciencesBeijing 100049China School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Minjiang Collaborative Center for theoretical physics Minjiang UniversityFuzhou 350108China

Lateral predictive coding is a recurrent neural network that creates energy-efficient internal representations by exploiting statistical regularity in sensory ***,we analytically investigate the trade-off between information robustness and energy in a linear model of lateral predictive coding and numerically minimize a free energy *** observed several phase transitions in the synaptic weight matrix,particularly a continuous transition that breaks reciprocity and permutation symmetry and builds cyclic dominance and a discontinuous transition with the associated sudden emergence of tight balance between excitatory and inhibitory *** optimal network follows an ideal gas law over an extended temperature range and saturates the efficiency upper bound of energy *** results provide theoretical insights into the emergence and evolution of complex internal models in predictive processing systems.

关键词： predictive coding recurrent neural network phase transition internal model free energy

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Asymmetric nucleation processes in spontaneous mode switch of active matter

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Communications in theoretical physics 2024年第5期76卷 154-158页

作者：杨冰王延颋 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

Flocking and vortical are two typical motion modes in active *** it is known that the two modes can spontaneously switch between each other in a finite-size system,the switching dynamics remain *** this work,by computer simulation of a two-dimensional Vicsek-like system with 1000 particles,we find from the perspective of the classical nucleation theory that the forward and backward switching dynamics are asymmetric:going from flocking to vortical is a one-step nucleation process,while the opposite is a two-step nucleation process,with the system staying in a metastable state before reaching the final flocking state.

关键词： active matter dynamics classical nucleation theory

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

Advancing space-based gravitational wave astronomy: Rapid parameter estimation via normalizing flows

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Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 20-33页

作者： Minghui Du Bo Liang He Wang Peng Xu Ziren Luo Yueliang Wu Center for Gravitational Wave Experiment National Microgravity LaboratoryInstitute of MechanicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Gravitational Wave Precision Measurement of Zhejiang Province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China International Centre for theoretical physics Asia-Pacific University of Chinese Academy of SciencesBeijing 100049China Taiji Laboratory for Gravitational Wave Universe(Beijing/Hangzhou) University of Chinese Academy of SciencesBeijing 100049China Lanzhou Center of theoretical physics Lanzhou UniversityLanzhou 730000China Hangzhou institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China institute of theoretical physics Chinese Academy of SciencesBeijing 100190China

Gravitational wave(GW) astronomy is witnessing a transformative shift from terrestrial to space-based detection, with missions like Taiji at the forefront. While the transition brings unprecedented opportunities for exploring massive black hole binaries(MBHBs), it also imposes complex challenges in data analysis, particularly in parameter estimation amidst confusion *** this gap, we utilize scalable normalizing flow models to achieve rapid and accurate inference within the Taiji environment. Innovatively, our approach simplifies the data's complexity, employs a transformation mapping to overcome the year-period time-dependent response function, and unveils additional multimodality in the arrival time parameter. Our method estimates MBHBs several orders of magnitude faster than conventional techniques, maintaining high accuracy even in complex backgrounds. These findings significantly enhance the efficiency of GW data analysis, paving the way for rapid detection and alerting systems and enriching our ability to explore the universe through space-based GW observation.

关键词： Taiji program gravitational wave detection parameter estimation machine learning