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Research in Astronomy and Astrophysics 2025年第1期25卷 7-8页

作者： Duncan R.Lorimer Department of Physics and Astronomy West Virginia University center for gravitational waves and cosmology West Virginia University

The Five-hundred-meter Aperture Spherical Telescope (FAST is living up to its promise as one of the world's premiere pulsa finding *** the center of FAST's many significan pulsar discoveries (which in total number 1000 from all projects to date) is the announcement by Han et al.(2025) of a further *** new discoveries are the latest installment from th FAST Galactic Plane Snapshot Survey (GPPS),bringing its total to751 *** details of the design and observational setup o the FAST GPPS can be found in Han et al.(2021).In brief,th survey is covering the northern Galactic plane in the FAST sky with latitudes|b|<10°with 5 minute pointings using the 19-beam1.4 GHz receiver on the FAST telescope,achieving a sensitivity to pulsars as faint as a fewμ*** date,with just under 25%of th total survey area completed,the discoveries include 107 rotating radio transients (RRATs),177 millisecond pulsars (MSPs) and 157binary *** most of the observations close to the Galacti plane complete,the rate of future discoveries will likely fall of slightly,but GPPS is set to eclipse the Parkes Multibeam Pulsa Survey (Manchester et al.2001) as the most successful pulsa survey to date.

关键词： (stars:) pulsars: general stars: neutron ISM: general

The deflection angle and quasi-periodic oscillations of an extended gravitational decoupled black hole solution

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Communications in Theoretical Physics 2025年第2期77卷 132-147页

作者： Farzan Mushtaq Xia Tiecheng Allah Ditta G Mustafa S K Maurya Department of Mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai University Department of Physics Zhejiang Normal University Research center of Astrophysics and cosmology Khazar University Department of Mathematical and Physical Sciences College of Arts and Sciences University of Nizwa

In weak field limits, we compute the deflection angle of a gravitational decoupling extended black hole(BH) solution. We obtained the Gaussian optical curvature by examining the null geodesic equations with the help of Gauss–Bonnet theorem(GBT). We also looked into the deflection angle of light by a black hole in weak field limits with the use of the Gibbons–Werner method. We verify the graphical behavior of the black hole after determining the deflection angle of light. Additionally, in the presence of the plasma medium, we also determine the deflection angle of the light and examine its graphical behavior. Furthermore, we compute the Einstein ring via gravitational decoupling extended black hole solution. We also compute the quasi-periodic oscillations and discuss their graphical behavior.

关键词： deflection of light Gauss-Bonnet theorem gravitational decoupling

Quasinormal modes of a black hole surrounded by a fluid of strings in Rastall gravity

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Chinese Physics C 2025年第02期 197-205页

作者：张明岳瑞宏邹德成 Faculty of Science Xi'an Aeronautical University National Joint Engineering Research center for Special Pump System Technology Xi'an Aeronautical University center for Gravitation and cosmology College of Physical Science and TechnologyYangzhou University College of Physics and Communication Electronics Jiangxi Normal University

In this paper, we explore the quasinormal modes(QNMs) of a black hole surrounded by a fluid of strings within the framework of Rastall gravity. We analyze the behavior of scalar, electromagnetic, and gravitational perturbations, focusing on the influences of black hole charge Q and angular momentum l on the quasinormal *** numerical results reveal a significant dependence on parameter ε. These trends are consistent across different types of perturbations, emphasizing the relationship between black hole parameters and QNM behavior.

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Penumbra lunar eclipse observations reveal anomalous thermal performance of Lunakhod 2 reflectors

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Chinese Physics B 2022年第5期31卷 212-218页

作者： Tian-Quan Gao Cai-Shi Zhang Hong-Chao Zhao Li-Xiang Zhou Xian-Lin Wu Hsienchi Yeh Ming Li MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational Physics&School of Physics and AstronomyFrontiers Science Center for TianQinCNSA Research Center for Gravitational WavesSun Yat-sen University(Zhuhai Campus)Zhuhai 519082China

As the signal reflected by the corner-cube reflector arrays is very weak and easily submerged during the full moon,we analyze the influence of the thermal effect of corner-cube reflector arrays on the intensity of lunar laser ranging *** ranging measurements during the penumbra lunar eclipse verify suspected thermal deformation in the Lunakhod 2 *** levels vary over two orders of magnitude as the penumbra eclipse *** can be explained by the change in the dihedral angle of the corner-cube reflectors caused by the *** results show that when the dihedral angle errors reach 1,the energy is reduced by 100 times compared with the ideal corner-cube *** the experiment,our findings suggest that when the corner-cube reflector arrays enter the penumbra of the earth,the effective echo signal level which reaches 0.18 photons/s far exceeds the historical level of the full ***,11 minutes after the penumbra lunar eclipse,the effective echo rate of Lunakhod 2 will drop two orders of *** mechanism can explain the acute signal deficit observed at full moon.

关键词： lunar laser ranging corner-cube reflector arrays dihedral angle errors penumbra lunar eclipse

Constraining the Hubble constant to a precision of about 1% using multi-band dark standard siren detections

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Science China(Physics,Mechanics & Astronomy) 2022年第5期65卷 114-140页

作者： Liang-Gui Zhu Ling-Hua Xie Yi-Ming Hu Shuai Liu En-Kun Li Nicola R.Napolitano Bai-Tian Tang Jian-Dong Zhang Jianwei Mei School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China MOE Key Laboratory of Tian Qin Mission Tian Qin Research Center for Gravitational PhysicsFrontiers Science Center for Tian QinCNSA Research Center for Gravitational WavesSun Yat-sen University(Zhuhai Campus)Zhuhai 519082China

gravitational wave signal from the inspiral of stellar-mass binary black hole can be used as standard sirens to perform cosmological *** inspiral covers a wide range of frequency bands,from the millihertz band to the audio-band,allowing for detections by both space-borne and ground-based gravitational wave *** this work,we conduct a comprehensive study on the ability to constrain the Hubble constant using the dark standard sirens,or gravitational wave events that lack electromagnetic *** acquire the redshift information,we weight the galaxies within the localization error box with photometric information from several bands and use them as a proxy for the binary black hole *** discover that Tian Qin is expected to constrain the Hubble constant to a precision of roughly 30%through detections of 10 gravitational wave events;in the most optimistic case,the Hubble constant can be constrained to a precision of<10%,assuming Tian Qin I+*** the optimistic case,the multi-detector network of Tian Qin and LISA is capable of constraining the Hubble constant to within 5%*** is worth highlighting that the multi-band network of Tian Qin and Einstein Telescope is capable of constraining the Hubble constant to a precision of about 1%.We conclude that inferring the Hubble constant without bias from photo-z galaxy catalog is achievable,and we also demonstrate self-consistency using the P-P *** the other hand,high-quality spectroscopic redshift information is crucial for improving the estimation precision of Hubble constant.

关键词： gravitational wave standard siren Hubble constant stellar-mass binary black hole photometric luminosity multi-band gravitational wave detection

Space-based optical lattice clocks as gravitational wave detectors in search for new physics

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Science China(Physics,Mechanics & Astronomy) 2025年第04期Mechanics & Astronomy) .卷 248-256页

作者： Bo Wang Bichu Li Qianqian Xiao Geyu Mo Yi-Fu Cai Department of Astronomy School of Physical SciencesUniversity of Science and Technology of China CAS Key Laboratory for Research in Galaxies and cosmology School of Astronomy and Space ScienceUniversity of Science and Technology of China Deep Space Exploration Laboratory

We investigate the sensitivity and performance of space-based optical lattice clocks（OLCs） in detecting gravitational waves,in particular the stochastic gravitational wave background（SGWB） at low frequencies(10-4, 1) Hz, which are inaccessible to ground-based detectors. We first analyze the response characteristics of a single OLC detector for SGWB detection and compare its sensitivity with that of laser interferometer space antenna（LISA）. Due to longer arm lengths, space-based OLC detectors can exhibit unique frequency responses and enhance the capability to detect SGWB in the low-frequency range, but the sensitivity of a single OLC detector remains insufficient overall compared with LISA. Then, as a preliminary plan, we adopt a method of crosscorrelation on two OLC detectors to improve the signal-to-noise ratio（SNR）. This method leverages the uncorrelated origins but statistically similar properties of noise in two detectors while the SGWB signal is correlated between them, thus achieving effective noise suppression and sensitivity enhancement. Future advancements in OLC stability are expected to further enhance their detection performance. This work highlights the potential of OLC detectors as a promising platform for SGWB detection,offering complementary capabilities to LISA, and opening an observational window into more astrophysical sources and the early universe.

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Electrodynamics with violations of Lorentz and U(1)gauge symmetries and their Hamiltonian structures

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Chinese Physics C 2024年第6期48卷 45-57页

作者：杨秀鹏李瀑飞朱涛 Institute for Theoretical Physics and cosmology Zhejiang University of TechnologyHangzhou 310032China United center for gravitational Wave Physics(UCGWP) Zhejiang University of TechnologyHangzhou 310032China

This study aims to investigate Lorentz/U(1)gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension of Lorentz breaking *** this purpose,we consider a general quadratic action of the modified electrodynamics with Lorentz/gauge-breaking operators and calculate the number of independent components of the operators at different dimensions in gauge invariance and *** this general action,we then analyze how Lorentz/gauge symmetry-breaking can change the Hamiltonian structure of the theories by considering Lorentz/gauge-breaking operators with dimension as *** show that the Lorentz-breaking operators with gauge invariance do not change the classes of the theory constrains and the number of physical degrees of freedom of the standard Maxwell *** U(1)gauge symmetry-breaking operators are present,the theories generally lack a first-class constraint and have one additional physical degree of freedom compared to the standard Maxwell electrodynamics.

关键词： standard model extension electrodynamics Lorentz violations

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 67-74页

作者： Song He Li Li Sai Wang Shao-Jiang Wang center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China School of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences(UCAS)Hangzhou 310024China Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physical Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China Max Planck Institute for gravitational Physics(Albert Einstein Institute) Am Muhlenberg 1Golm 14476Germany

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition,yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT)left *** specific baryon chemical poten-tial,the first-order QCD phase transition agrees with the observational constraint of baryon ***,therefore,provides a scenario for phase transition gravitational waves(GWs)within the standard model of particle *** these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA)observations,the duration of this FoPT can be well constrained,and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Thin accretion disk around a four-dimensional Einstein- Gauss-Bonnet black hole

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Chinese Physics C 2021年第1期45卷 366-374页

作者： Cheng Liu Tao Zhu Qiang Wu Institute tor Theoretical Physics&cosmology Zhejiang University of TechnologyHangzhou 310023China United center tor gravitational Wave Physics(UCGWP) Zhejiang University of TechnologyHangzhou 310023China

Recently,a novel four-dimensional Einstein-Gauss-Bonnet(4 EGB) theory of gravity was proposed by Glavan and Lin [*** and ***,***.124,081301(2020)],which includes a regularized GaussBonnet term using the re-scalaring of the Gauss-Bonnet coupling constant α→α/(D-4) in the limit D→*** theory has also been reformulated to a specific class of the Homdeski theory with an additional scalar degree of freedom and to a spatial covariant version with a Lagrangian multiplier,which can eliminate the scalar ***,we study the physical properties of the electromagnetic radiation emitted from a thin accretion disk around a static spherically symmetric black hole in 4 EGB *** this purpose,we assume the disk is in a steady-state and in hydrodynamic and thermodynamic equilibrium,so that the emitted electromagnetic radiation is a black body *** study in detail the effects of the Gauss-Bonnet coupling constant α in 4 EGB gravity on the energy flux,temperature distribution,and electromagnetic spectrum of the *** an increase in the parameter α,the energy flux,temperature distribution,and electromagnetic spectrum of the accretion disk all *** also show that the accretion efficiency increases with the growth of the parameter α.Our results indicate that the thin accretion disk around a static spherically symmetric black hole in 4 EGB gravity is hotter,more luminous,and more efficient than that around a Schwarzschild black hole with the same mass for positive α,while it is cooler,less luminous,and less efficient for negative α.

关键词： black hole thin accretion disk moditled gravity

Power-law Distribution and Scale-invariant Structure from the First CHIME/FRB Fast Radio Burst Catalog

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Research in Astronomy and Astrophysics 2023年第2期23卷 42-46页

作者： Zi-Han Wang Yu Sang Xue Zhang center for Gravitation and cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009.China Shanghai Frontier Science Research center for gravitational Wave Detection School of Aeronautics and AstronauticsShanghai Jiao Tong UniversityShanghai 200240China

We study the statistical property of fast radio bursts(FRBs) based on a selected sample of 190 one-off FRBs in the first CHIME/FRB *** power law models are used in the analysis,and we find the cumulative distribution functions of energy can be well fitted by bent power law and thresholded power law *** distribution functions of fluctuations of energy well follow the Tsallis q-Gaussian *** q values in the Tsallis q-Gaussian distribution are constant with small fluctuations for different temporal scale intervals,indicating a scale-invariant structure of the *** earthquakes and soft gamma repeaters show similar properties,which are consistent with the predictions of self-organized criticality systems.

关键词： methods statistical-radio continuum galaxies-catalogs