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The first confirmed gravitational wave detection in LIGO's second observational run

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Science China(Physics,Mechanics & Astronomy) 2017年第12期60卷 74-79页

作者： Jin Li xilong fan College of Physics Chongqing University School of Physics and Electronics Information Hubei University of Education

In this article,we describe the results concerning the third coincident signal GW170104 from the coalescence of binary black holes（BBHs）during the second observation run（O2）.The result was obtained from the LIGO Scientific Collaboration and the Virgo *** the first and second gravitational waves（GWs）detections in the first observation run（O1）[1],recently LIGO has observed a third coincident signal GW170104 from the coalescence of BBHs

关键词： gravitational observational waveform concerning aligned template astronomy Bayesian instrumental Gabor

Probing the Large-scale Structure of the Universe Through Gravitational Wave Observations

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Research in Astronomy and Astrophysics 2022年第1期22卷 60-67页

作者： Xiaoyun Shao Zhoujian Cao xilong fan Shichao Wu Department of Astronomy Beijing Normal UniversityBeijing 100875China School of Physics and Technology Wuhan UniversityWuhan 430072China Max-Planck-Institut fur Gravitationsphysik(Albert-Einstein-Institut) D-30167 HannoverGermany Leibniz Universitat Hannover D-30167 HannoverGermany

The improvements in the sensitivity of the gravitational wave(GW) network enable the detection of several large redshift GW sources by third-generation GW detectors. These advancements provide an independent method to probe the large-scale structure of the universe by using the clustering of the binary black holes(BBHs). The black hole catalogs are complementary to the galaxy catalogs because of large redshifts of GW events, which may imply that BBHs are a better choice than galaxies to probe the large-scale structure of the universe and cosmic evolution over a large redshift range. To probe the large-scale structure, we used the sky position of the BBHs observed by third-generation GW detectors to calculate the angular correlation function and the bias factor of the population of BBHs. This method is also statistically significant as 5000 BBHs are simulated. Moreover, for the third-generation GW detectors, we found that the bias factor can be recovered to within 33% with an observational time of ten years. This method only depends on the GW source-location posteriors;hence, it can be an independent method to reveal the formation mechanisms and origin of the BBH mergers compared to the electromagnetic method.

关键词： gravitational waves (cosmology:)large-scale structure of universe black hole physics

Tail wavelets in merger of binary compact objects

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Chinese Physics C 2020年第7期44卷 1-7页

作者： Kai Lin Wei-Liang Qian xilong fan Hongsheng Zhang Institute of Geophysics and Geoinformatics China University of GeosciencesWuhan 430074China Escola de Engenharia de Lorena Universidade de Sao Paulo12602-810LorenaSPBrazil Faculdade de Engenharia de Guaratingueta Universidade Estadual Paulista12516-410GuaratinguetaSPBrazil School of Physical Science and Technology Yangzhou UniversityYangzhou 225002China School of Physics and Technology Wuhan UniversityWuhan 430072China School of Physics and Technology University of Jinan336 West Road of Nan XinzhuangJinan 250022China State Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

We present a model for tail wavelets,a phenomenon known as"echo"in the *** tail wavelet may appear in signal reconnaissances in the merger of binary compact objects,including black holes and neutron *** show that the dark matter surrounding the compact objects lead to a speculated tail wavelet following the main gravitational wave(GW).We demonstrate that the radiation pressure of the main wave is fully capable of pushing away the surrounding matter to some altitude,and splashing down of the matter excites the tail wavelet after ringing down of the main *** illustrate this concept in a simplified model,where numerical estimations are conducted on the specific distribution of dark matter outside the black hole horizon and the threshold values in accordance with *** study the full back reaction of the surrounding dark matter to the metric and find that the effect on to the tail wavelets is *** reveal the fine difference between the tail wavelets of a dressed and a bare black *** demonstrate that the tail wavelet can appear as a natural phenomenon in the frame of general relativity,without invoking modified gravities or quantum effects.

关键词： gravitational wave dark matter tail wavelet

Poisson-Arago spot for gravitational waves

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Science China(Physics,Mechanics & Astronomy) 2021年第12期64卷 2-7页

作者： HongSheng Zhang xilong fan School of Physics and Technology University of JinanJinan 250022China School of Physics and Technology Wuhan UniversityWuhan 430072China

For the observer at infinity, a Schwarzschild black hole serves as an attractive opaque disk with a radius of 3√3 M that will produce the diffraction pattern of gravitational waves(GWs). In this study, we demonstrate that a bright spot, which is a diffraction effect analogous to the Poisson-Arago spot in optics, will appear when an ingoing(quasi-)plane GW is diffracted by a Schwarzschild black hole. Here, we propose the diffraction effect of the GWs described by the exact diffraction solution of the GWs using the Heun function. For the first time, the Fresnel half-wave zone method is proposed to calculate the angular part of the GW scattering stripes for the observer at infinity. The prospect of observing the diffraction bright spot is discussed with an eikonal approximation. For normal incidence(quasi)-plane waves with 100 Hz(0.1 Hz) frequency diffracted by the central black hole of the Milky Way, the time delay between the Earth bathed in a bright spot and the minimum of the first dark stripe is 3.86(3860) d. We will witness the second bright fringe(40% amplitude of the central bright spot) after 6.2(6200) d. This new diffraction pattern involving the early phase of inspirals and pulsars as continuous gravitational wave sources is a potential scientific target for future space-and ground-based gravitational wave detectors, respectively.

关键词： gravitational waves diffraction black hole

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透镜化引力波的散射问题及其应用

科学通报 2021年第20期66卷 2516-2528页

作者：范锡龙武汉大学物理科学与技术学院武汉430072

引力波的直接探测开启了引力波天文学时代.引力波传播路径中的大质量天体,例如黑洞、星系、星系团会散射引力波,发生引力透镜化引力波现象.这种现象包含动态引力场(引力波)、静态引力场(透镜体)以及宇宙学信息.透镜化引力波是引力波探... 详细信息

引力波的直接探测开启了引力波天文学时代.引力波传播路径中的大质量天体,例如黑洞、星系、星系团会散射引力波,发生引力透镜化引力波现象.这种现象包含动态引力场(引力波)、静态引力场(透镜体)以及宇宙学信息.透镜化引力波是引力波探测器重要科学目标之一.本文介绍了利用测地线方程、透镜方程和波动方程研究透镜化引力波的定态散射问题,回顾了利用透镜化引力波-电磁波系统研究引力波张量特性、干涉和衍射效应,以及其在引力波速度、哈勃常数、宇宙曲率、透镜体质量和子结构等方面的应用.

关键词：引力波引力透镜衍射宇宙学

Hawking radiation received at infinity in higher dimensional Reissner-Nordstrom black hole spacetimes

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Chinese Physics C 2021年第8期45卷 182-189页

作者： Kai Lin Wei-Liang Qian xilong fan Bin Wang Elcio Abdalla Hubei Subsurface Multi-scale Imaging Key Laboratory Institute of Geophysics and GeomaticsChina University of GeosciencesWuhan 430074China Escola de Engenharia de Lorena Universidade de Sao Paulo12602-810LorenaSPBrazil Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Faculadade de Engenharia de Guaratingueta Universidade Estadual PaulistaGuaratinguetaSPBrazil School of Physics and Technology Wuhan UniversityWuhan 430072China Instituto de Fisica Universidade de Sao PauloSao PauloBrazil

In this study,we investigate the Hawking radiation in higher dimensional Reissner-Nordstrom black holes as received by an observer located at *** frequency-dependent transmission rates,which deform the thermal radiation emitted in the vicinity of the black hole horizon,are evaluated *** addition to those in four-dimensional spacetime,the calculations are extended to higher dimensional Reissner-Nordstrom metrics,and the results are observed to be sensitive to the spacetime dimension to an ***,we observe that the transmission coefficient practically vanishes when the frequency of the emitted particle approaches *** increases with frequency and eventually saturates to a certain *** four-dimensional spacetime,the above result is demonstrated to be mostly independent of the metric's parameter and the orbital quantum number of the particle,when the location of the event horizon,rh,and the product of the charges of the black hole and the particle qQ are ***,for higher-dimensional scenarios,the convergence becomes more ***,the difference between states with different orbital quantum numbers is observed to be more *** the magnitude of the product of charges qQ becomes more significant,the transmission coefficient exceeds *** other words,the resultant spectral flux is amplified,which results in an accelerated process of black hole *** relationship of the calculated outgoing transmission coefficient with existing results on the greybody factor is discussed.

关键词： Hawking radiation Reissner-Nordstrom black hole superradiation

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贝叶斯引力波多信使天文学

中国科学：物理学、力学、天文学 2018年第7期48卷 53-64页

作者：范锡龙湖北第二师范学院物理与机电工程学院武汉430205

对于双黑洞、双中子星并合引力波及其电磁对应体、宿主星系的观测开启了引力波多信使天文学时代.本文简要介绍引力波、电磁对应体、宿主星系联合观测在提高信号探测效率、增加对波源物理性质的理解、挖掘波源群族性质等方面的基本概念,... 详细信息

对于双黑洞、双中子星并合引力波及其电磁对应体、宿主星系的观测开启了引力波多信使天文学时代.本文简要介绍引力波、电磁对应体、宿主星系联合观测在提高信号探测效率、增加对波源物理性质的理解、挖掘波源群族性质等方面的基本概念,重点介绍一个贝叶斯引力波天文学框架处理上述问题的方法和此框架在引力波-宿主星系、引力波-短伽玛暴联合观测方面的应用.

关键词：引力波伽玛射线暴星系

Understanding the Predication Mechanism of Deep Learning through Error Propagation among Parameters in Strong Lensing Case

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Research in Astronomy and Astrophysics 2023年第12期23卷 252-262页

作者： xilong fan Peizheng Wang Jin Li Nan Yang School of Physics and Technology Wuhan UniversityWuhan 430072China School of Software Technology Zhejiang UniversityNingbo 315048China Department of Physics Chongqing UniversityChongqing 401331China Department of Electronical Information Science and Technology Xingtai UniversityXingtai 054001China

The error propagation among estimated parameters reflects the correlation among the *** study the capability of machine learning of"learning"the correlation of estimated *** show that machine learning can recover the relation between the uncertainties of different parameters,especially,as predicted by the error propagation *** lensing can be used to probe both astrophysics and *** a practical application,we show that the machine learning is able to intelligently find the error propagation among the gravitational lens parameters(effective lens mass ML and Einstein radiusθ_(E))in accordance with the theoretical formula for the singular isothermal ellipse(SIE)lens *** relation of errors of lens mass and Einstein radius,(e.g.,the ratio of standard deviations F=σ_(ML)/σ_(θ_(E)))predicted by the deep convolution neural network are consistent with the error propagation formula of the SIE lens *** a proof-of-principle test,a toy model of linear relation with Gaussian noise is *** found that the predictions obtained by machine learning indeed indicate the information about the law of error propagation and the distribution of *** propagation plays a crucial role in identifying the physical relation among parameters,rather than a coincidence relation,therefore we anticipate our case study on the error propagation of machine learning predictions could extend to other physical systems on searching the correlation among parameters.

关键词： gravitational lensing strong-methods data analysis-Galaxy fundamental parameters

Applying deep neural networks to the detection and space parameter estimation of compact binary coalescence with a network of gravitational wave detectors

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Science China(Physics,Mechanics & Astronomy) 2019年第6期62卷 122-129页

作者： xilong fan Jin Li Xin Li YuanHong Zhong JunWei Cao Department of Physics and Astronomy Hubei University of Education Department of Physics Chongqing University College of Communication Chongqing University Research Institute of Information Technology Tsinghua University

In this paper, we study an application of deep learning to the advanced laser interferometer gravitational wave observatory(LIGO)and advanced Virgo coincident detection of gravitational waves(GWs) from compact binary star mergers. This deep learning method is an extension of the Deep Filtering method used by George and Huerta(2017) for multi-inputs of network *** coincident time series data sets in advanced LIGO and advanced Virgo detectors are analyzed for estimating source luminosity distance and sky location. As a classifier, our deep neural network(DNN) can effectively recognize the presence of GW signals when the optimal signal-to-noise ratio(SNR) of network detectors ≥ 9. As a predictor, it can also effectively estimate the corresponding source space parameters, including the luminosity distance D, right ascension α, and declination δ of the compact binary star mergers. When the SNR of the network detectors is greater than 8, their relative errors are all less than 23%.Our results demonstrate that Deep Filtering can process coincident GW time series inputs and perform effective classification and multiple space parameter estimation. Furthermore, we compare the results obtained from one, two, and three network detectors;these results reveal that a larger number of network detectors results in a better source location.

关键词： deep neural networks advanced LIGO and advanced Virgo coincident detection of gravitational waves multiple space parameter estimation