It has been a half-decade since the first direct detection of gravitational waves, which signifies the coming of the era of the gravitational-wave astronomy and gravitational-wave cosmology. The increasing number of t...It has been a half-decade since the first direct detection of gravitational waves, which signifies the coming of the era of the gravitational-wave astronomy and gravitational-wave cosmology. The increasing number of the detected gravitational-wave events has revealed the promising capability of constraining various aspects of cosmology, astronomy, and gravity. Due to the limited space in this review article, we will briefly summarize the recent progress over the past five years, but with a special focus on some of our own work for the Key Project "Physics associated with the gravitational waves" supported by the National Natural Science Foundation of China. In particular,(1) we have presented the mechanism of the gravitational-wave production during some physical processes of the early Universe, such as inflation, preheating and phase transition, and the cosmological implications of gravitational-wave measurements;(2) we have put constraints on the neutron star maximum mass according to GW170817 observations;(3) we have developed a numerical relativity algorithm based on the finite element method and a waveform model for the binary black hole coalescence along an eccentric orbit.展开更多
Recently, the North American Nanohertz Observatory for Gravitational Waves(NANOGrav) claimed the detection of a stochastic common-spectrum process of the pulsar timing array(PTA) time residuals from their 12.5 year da...Recently, the North American Nanohertz Observatory for Gravitational Waves(NANOGrav) claimed the detection of a stochastic common-spectrum process of the pulsar timing array(PTA) time residuals from their 12.5 year data, which might be the first detection of the stochastic background of gravitational waves(GWs). We show that the amplitude and the power index of such waves imply that they could be the secondary GWs induced by the peaked curvature perturbation with a dust-like post inflationary era with-0.091 ≤ w ≤ 0.048. Such stochastic background of GWs naturally predicts substantial existence of planet-mass primordial black holes(PBHs), which can be the lensing objects for the ultrashort-timescale microlensing events observed by the Optical Gravitational Lensing Experiment(OGLE).展开更多
NANOGrav has recently reported the detection of a common-spectrum process via the time-of-arrival data of 47 millisecond pulsars[1],which could be interpreted by a stochastic gravitational wave background(SGWB)in the ...NANOGrav has recently reported the detection of a common-spectrum process via the time-of-arrival data of 47 millisecond pulsars[1],which could be interpreted by a stochastic gravitational wave background(SGWB)in the nanohertz frequency band(f∼10−9 Hz)with energy density parameterΩGW∼10−9.Despite the vague quadrupole correlation that obstructs the identification of gravitational waves,this report hints the possibility of some new physics at around or below 100 MeV that can generate nanohertz gravitational waves by,for instance,the first order phase transition(FOPT).展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.11690021,11690022,11690023,and 11690024)。
文摘It has been a half-decade since the first direct detection of gravitational waves, which signifies the coming of the era of the gravitational-wave astronomy and gravitational-wave cosmology. The increasing number of the detected gravitational-wave events has revealed the promising capability of constraining various aspects of cosmology, astronomy, and gravity. Due to the limited space in this review article, we will briefly summarize the recent progress over the past five years, but with a special focus on some of our own work for the Key Project "Physics associated with the gravitational waves" supported by the National Natural Science Foundation of China. In particular,(1) we have presented the mechanism of the gravitational-wave production during some physical processes of the early Universe, such as inflation, preheating and phase transition, and the cosmological implications of gravitational-wave measurements;(2) we have put constraints on the neutron star maximum mass according to GW170817 observations;(3) we have developed a numerical relativity algorithm based on the finite element method and a waveform model for the binary black hole coalescence along an eccentric orbit.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC2201502)supported by the European Union’s Horizon 2020 Research and Innovation Program under the Marie Sk?odowska-Curie(Grant No.754496)+4 种基金supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB15)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-006)the National Natural Science Foundation of China(Grant No.12047503)the Japan Society for the Promotion of Science Grant-in-Aid for Early-Career Scientists(Grant No.JP20K14461)the World Premier International Research Center Initiative(WPI Initiative),MEXT,Japan。
文摘Recently, the North American Nanohertz Observatory for Gravitational Waves(NANOGrav) claimed the detection of a stochastic common-spectrum process of the pulsar timing array(PTA) time residuals from their 12.5 year data, which might be the first detection of the stochastic background of gravitational waves(GWs). We show that the amplitude and the power index of such waves imply that they could be the secondary GWs induced by the peaked curvature perturbation with a dust-like post inflationary era with-0.091 ≤ w ≤ 0.048. Such stochastic background of GWs naturally predicts substantial existence of planet-mass primordial black holes(PBHs), which can be the lensing objects for the ultrashort-timescale microlensing events observed by the Optical Gravitational Lensing Experiment(OGLE).
文摘NANOGrav has recently reported the detection of a common-spectrum process via the time-of-arrival data of 47 millisecond pulsars[1],which could be interpreted by a stochastic gravitational wave background(SGWB)in the nanohertz frequency band(f∼10−9 Hz)with energy density parameterΩGW∼10−9.Despite the vague quadrupole correlation that obstructs the identification of gravitational waves,this report hints the possibility of some new physics at around or below 100 MeV that can generate nanohertz gravitational waves by,for instance,the first order phase transition(FOPT).
