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Chinese Physics Letters 2013年第10期30卷 30-33页

作者：童明雷燕保荣赵成仕尹东山赵书红杨廷高高玉平 National Time Service Center Chinese Academy of SciencesXi'an 710600 Key Laboratory of Time and Frequency Primary Standards Chinese Academy of SciencesXi'an 710600 Key Laboratory of Precision Navigation and Timing Technology Chinese Academy of SciencesXi'an 710600

The pulsar timing residuals induced by gravitational waves from non-evolving single binary sources with general elliptical orbits are *** different orbital eccentricities,the timing residuals present different *** standard deviations of the timing residuals induced by a fixed gravitational wave source are calculated for different values of the *** also analyze the timing residuals of PSR J0437-4715 induced by one of the best known single gravitational wave sources,the supermassive black hole binary in the blazar OJ287.

关键词： massive gravitational properties

Analytic perturbation solutions to the Venusian orbiter due to the nonspherical gravitational potential

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Science China Mathematics 2000年第5期43卷 552-560页

作者：刘林 C.K.Shum Department of Astronomy Nanjing University Nanjing 210093 China The Texas University at Austin Center for Space Research

The analytic perturbation solutions to the motions of a planetary orbiter given in this paper are effective for0< e< 1, where e is the orbital eccentricity of the orbiter. in the solution, it is as-sumed that the rotation of the central body is slow, and its astronomical background is clear. Examples for such planets in the solar system are Ven黶 and Mercury. The perturbation solution is tested numer-ically on two Venusian orbiters with eccentric orbits, PVO and Magellan, and found to be effective.

关键词： slow rotation central body Venusian orbiter nonspherical gravitational potential analytic per- turbation solutions.

Binary neutron stars gravitational wave detection based on wavelet packet analysis and convolutional neural networks

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Frontiers of physics 2020年第2期15卷 111-117页

作者： Bai-Jiong Lin Xiang-Ru Li Wo-Liang Yu South China Normal University Guangzhou 510631China

This work investigates the detection of binary neutron stars gravitational wave based on convolutional neural network(CNN).To promote the detection performance and efficiency,we proposed a scheme based on wavelet packet(WP)decomposition and *** WP decomposition is a time-frequency method and can enhance the discriminant features between gravitational wave signal and noise before *** CNN conducts the gravitational wave detection by learning a function mapping relation from the data under being processed to the space of detection *** function-mapping-relation style detection scheme can detection efficiency *** this work,instrument effects are con-sidered,and the noise are computed from a power spectral density(PSD)equivalent to the Advanced LIGO design *** quantitative evaluations and comparisons with the state-of-art method matched filtering show the excellent performances for BNS gravitational wave *** efficiency,the current experiments show that this WP-CNN-based scheme is more than 960 times faster than the matched filtering.

关键词： gravitational waves algorithms astrostatistics techniques

Relation between gravitational mass and baryonic mass for non-rotating and rapidly rotating neutron stars

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Frontiers of physics 2020年第2期15卷 119-128页

作者： He Gao Shun-Ke Ai Zhou-Jian Cao Bing Zhang Zhen-Yu Zhu Ang Li Nai-Bo Zhang Andreas Bauswein Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Physics and Astronomy University of Nevada Las VegasNV 89154USA Department of Astronomy Xiamen UniversityXiamen 361005China Institute for Theoretical Physics Max-von-Laue-Strasse 160438 FrankfurtGermany Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsInstitute of Space SciencesShandong UniversityWeihai 264209China GSI Helmholtzzentrum fiir Schwerionenforschung Planckstrafie 164291 DarmstadtGermany

With a selected sample of neutron star(NS)equations of state(EOSs)that are consistent with the current observations and have a range of maximum masses,we investigate the relations between NS gravitational mass Mg and baryonic mass and the relations between the maximum NS mass supported through uniform rotation(Mmax)and that of nonrotating NSs(Mtov).We find that for an EOS-independent quadratic,universal transformation formula(Mb=Mg+A×M^2/g),the best-fit A value is 0.080 for non-rotating NSs,0.064 for maximally rotating NSs,and 0.073 when NSs with arbitrary rotation are *** residual error of the transformation is?0.1M⊙ for non-spin or maximum-spin,but is as large as?0.2M⊙ for all *** different EOSs,we find that the parameter A for non-rotating NSs is proportional to R^-1/1.4(where R1.4 is NS radius for 1.4M⊙ in units of km).For a particular EOS,if one adopts the best-fit parameters for different spin periods,the residual error of the transformation is smaller,which is of the order of O.O1M⊙ for the quadratic form and less than O.O1M⊙ for the cubic form(Mb=Mg+A1×M^2/g+A2×M^3/g).We also find a very tight and general correlation between the normalized mass gain due to spin △m≡(Mmax-MTOV)MTOV and the spin period normalized to the Keplerian period P,i.e.,log10 △m=(-2.74±0.05)log10 P+log10(0.20±0.01),which is independent of EOS *** empirical relations are helpful to study NS-NS mergers with a long-lived NS merger product using multi-messenger *** application of our results to GW170817 is discussed.

关键词： gravitational waves

Testing Photons Coupled to Weyl Tensor with gravitational Time Advancement

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Communications in Theoretical Physics 2018年第12期69卷 721-727页

作者：李刚邓雪梅 Purple Mountain Observatory Chinese Academy of SciencesNanjing 210034China School of Astronomy and Space Science University of Science and Technology of ChinaAnhui 230026China

Classical Solar System tests of photons coupled to Weyl tensor with two polarizations were studied in a recent work. A coupling strength parameter α in this model was firstly obtained as |α| 4 × 10^(11) m^2 by using available datasets in the Solar System. In this paper, a new test called by gravitational time advancement is proposed and investigated to test such the coupling. This new test, which is quite different from Shapiro time delay, depends strongly on round-trip proper time span(not coordinate time one) of flight of radio pulses between an observer on the Earth and a distant spacecraft. For ranging a spacecraft getting far away from the Sun, two special cases(the superior/inferior conjunctions) are used to analyse the observability in the advancement contributed by the Weyl coupling. We found that the situation of the inferior conjunction is more suitable for detecting the advancement caused by such the Weyl *** either case, two kinds of polarizations make the advancement in the model smaller or larger than the one of general relativity. Although the observability in the advancement could be out of the reach of already existing technology, the implement of planetary laser ranging and optical clocks might provide us more insights on such the Weyl coupling in the near future.

关键词： gravitation experimental tests of gravitational theories light propagation astrometry

The gravitational gradient tensor’s invariants and the related boundary conditions

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Science China Earth Sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2,3 & ZHAO DongMing4 1 College of Earth Science, Graduate University of Chinese Academy of Sciences, Beijing 100049, China 2 Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China 3 State Key Laboratory of Astronautic Dynamics, Xi’an 710043, China 4 Zhengzhou Institute of Surveying and Mapping, Zhengzhou 450052, China College of Earth Science Graduate University of Chinese Academy of Sciences Beijing China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China State Key Laboratory of Astronautic Dynamics Xi’an China Zhengzhou Institute of Surveying and Mapping Zhengzhou China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2-term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2/2 T), which is approximately equivalent to O(T2). Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 200, and the models with regard to effect of J2-term have accuracies of 10-8 and the order can reach up to 280.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

A gravitational Wave Background from Primordial Black Hole Lattices in Matter Dominated Era

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Communications in Theoretical Physics 2019年第10期71卷 1196-1204页

作者：王科 National Astronomical Observatories Chinese Academy of Sciences

We use the wide-used Einstein Toolkit to solve the Einstein constraints and then simulate the expansion of primordial black hole lattices(PBHLs) with different value of f PBH and m PBH. We find that f PBH plays an important role during the evolution of PBHLs. Since the motion of primordial black holes(PBHs) caused by the expansion of PBHLs occurs at speeds close to that of light, we expect the emission of gravitational waves(GWs) during the expansion of PBHLs. We use both analytical estimates and numerical simulations to cross check the production of GWs in expanding PBHLs.

关键词： Einstein Toolkit primordial black hole lattices gravitational waves

Revealing the amplitude of primordial curvature perturbations on small scales from primordial black hole binaries for gravitational wave detection

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Science China(Physics,Mechanics & Astronomy) 2023年第6期66卷 86-86页

作者： Rong-Gen Cai CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

Primordial black holes (PBHs) have been intensively investigated in cosmology as they are considered a potential candidate to be used as sources of the observed gravitational wave (GW) signals [1]. A substantial increase in primordial curvature perturbations on small scales is one of the natural methods to generate PBHs (smaller than a single Mpc)[2]. Hence, the PBH scenario of observed GW events by LIGO/VIRGO [3] offers an opportunity to analyze the primordial curvature perturbations on small scales, which have not yet been explored systematically because of lack of corresponding observations.

关键词： scales gravitational curvature

The delay time of gravitational wave-gamma-ray burst associations

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Frontiers of physics 2019年第6期14卷 133-143页

作者： Bing Zhang Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA

The first gravitational wave(GW)-gamma-ray burst(GRB)association,GW170817/GRB 170817A,had an offset in time,with the GRB trigger time delayed by^1.7 s with respect to the merger time of the GW *** generally discuss the astrophysical origin of the delay time,Δt,of GW-GRB associations within the context of compact binary coalescence(CBC)-short GRB(sGRB)associations and GW burst-long GRB(lGRB)*** general,the delay time should include three terms,the time to launch a clean(relativistic)jet,Δtjet;the time for the jet to break out from the surrounding medium,Δtbo;and the time for the jet to reach the energy dissipation and GRB emission site,Δ*** CBC-sGRB associations,Δtjet andΔtbo are correlated,and the final delay can be from 10 ms to a few *** GWB-lGRB associations,Δtjet andΔtbo are *** latter is at least^10 s,so thatΔt of these associations is at least this *** certain jet launching mechanisms of lGRBs,Δt can be minutes or even hours long due to the extended engine waiting time to launch a *** discuss the cases of GW170817/GRB 170817A and GW150914/GW150914-GBM within this theoretical framework and suggest that the delay times of future GW/GRB associations will shed light into the jet launching mechanisms of GRBs.

关键词： gravitational waves gamma-ray bursts general

Generalized gravitomagnetic field and gravitational waves

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Science China(Physics,Mechanics & Astronomy) 2019年第11期62卷 138-141页

作者： XiaoKai He JiLiang Jing ZhouJian Cao School of Mathematics and Computational Science Hunan First Normal UniversityChangsha 410205China Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Educationand SynergeticInnovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangshaHunan 410081China Department of Astronomy Beijing Normal UniversityBeijing 100875China

Synge was the first to derive the geodesic deviation entirely mathematically (1)Only later did people realize its importance [2] for describing the physical behavior of curved spacetime [3], particularly that it can unambiguously manifest gravitational waves (4, 5)The geodesic deviation relates purely to the 'electric' part of a curved spacetime, while the complementary 'magnetic' part is related to the way gyroscopes adapt to geodesics. For Ricci flat spacetimes.

关键词： Generalized gravitomagnetic field and gravitational waves