Laser interferometry plays a crucial role in laser ranging for high-precision space missions such as GRACE(Gravity Recovery and Climate Experiment)Follow-On-like missions and gravitational wave detectors.For such accu...Laser interferometry plays a crucial role in laser ranging for high-precision space missions such as GRACE(Gravity Recovery and Climate Experiment)Follow-On-like missions and gravitational wave detectors.For such accuracy of modern space missions,a precise relativistic model of light propagation is required.With the post-Newtonian approximation,we utilize the Synge world function method to study the light propagation in the Earth’s gravitational field,deriving the gravitational delays up to order c^(−4).Then,we investigate the influences of gravitational delays in three inter-satellite laser ranging techniques,including one-way ranging,dual one-way ranging,and transponder-based ranging.By combining the parameters of Kepler orbit,the gravitational delays are expanded up to the order of e^(2)(e is the orbital eccentricity).Finally,considering the GRACE Follow-On-like missions,we estimate the gravitational delays to the level of picometer.The results demonstrate some high-order gravitational and coupling effects,such as c^(−4)-order gravitational delays and coupling of Shapiro and beat frequency,which may be non-negligible for higher precision laser ranging in the future.展开更多
In a test of the weak equivalence principle （WEP） with a rotating torsion pendulum, it is important to estimate the amplitude of the modulation signal with high precision. We use a torsional filter to remove the fre...In a test of the weak equivalence principle （WEP） with a rotating torsion pendulum, it is important to estimate the amplitude of the modulation signal with high precision. We use a torsional filter to remove the free oscillation signal and employ the correlation method to estimate the amplitude of the modulation signal. The data analysis of an experiment shows that the uncertainties of amplitude components of the modulation signal obtained by the correlation method are in agreement with those due to white noise. The power spectral density of the modulation signal obtained by the correlation method is about one order higher than the thermal noise limit. It indicates that the correlation method is an effective way to estimate the amplitude of the modulation signal and it is instructive to conduct a high-accuracy WEP test.展开更多
In the torsion pendulum experiments, the thermal noise sets the most fundamental limit to the accurate estimation of the amplitude of the signal with known frequency. The variance of the conventional method can meet t...In the torsion pendulum experiments, the thermal noise sets the most fundamental limit to the accurate estimation of the amplitude of the signal with known frequency. The variance of the conventional method can meet the limit only when the measurement time is much longer than the relaxation time of the pendulum. By using the maximum likelihood estimation and the equation-of-motion filter operator, we propose an optimal(minimum variance, unbiased) amplitude estimation method without limitation of the measurement time, where thermal fluctuation is the leading noise. While processing the experimental data tests of the Newtonian gravitational inverse square law, the variance of our method has been improved than before and the measurement time of determining the amplitude with this method has been reduced about half than before for the same uncertainty. These results are significant for the torsion experiment when the measurement time is limited.展开更多
In the measurement of the Newtonian gravitational constant G with the time-of-swing method,the influence of the Earth's rotation has been roughly estimated before,which is far beyond the current experimental preci...In the measurement of the Newtonian gravitational constant G with the time-of-swing method,the influence of the Earth's rotation has been roughly estimated before,which is far beyond the current experimental precision.Here,we present a more complete theoretical modeling and assessment process.To figure out this effect,we use the relativistic Lagrangian expression to derive the motion equations of the torsion pendulum.With the correlation method and typical parameters,we estimate that the influence of the Earth's rotation on G measurement is far less than 1 ppm,which may need to be considered in the future high-accuracy experiments of determining the gravitational constant G.展开更多
The effect of the Raman-pulse duration related to the magnetic field gradient, as a systematic error, is playing an important role on evaluating the performance of high-precision atomic gravimeters. We study this effe...The effect of the Raman-pulse duration related to the magnetic field gradient, as a systematic error, is playing an important role on evaluating the performance of high-precision atomic gravimeters. We study this effect with a simplified theoretical model of the time-propagation operator. According to the typical parameters, we find that this effect should be taken into account when the gravimeter reaches an accuracy of 10^-10g, and the larger the pulse duration is, the more obvious the systematic effect will be. Finally, we make a simple discussion on the possibility of testing this effect.展开更多
We conduct numerical investigations on the critical collapse of spherically symmetric massless scalar fields in asymptotically anti-de Sitter spacetime.Our primary focus is on the behavior of the critical amplitude un...We conduct numerical investigations on the critical collapse of spherically symmetric massless scalar fields in asymptotically anti-de Sitter spacetime.Our primary focus is on the behavior of the critical amplitude under various initial configurations of the scalar field.Through our numerical results,we obtain a formula that determines critical amplitude in terms of cosmological constantΛ:A^(*)∝(0.01360σ/v_(0)+0.001751)Λ,whereσdenotes the initial width of the scalar field and is the initial position of the scalar field.Notably,we highlight that the slope of this linear relationship depends on the initial configuration of the scalar field.展开更多
We study the energy issue in critical collapse.It is found that in critical collapse,the contribution from the material energy is greater than that from the gravitational energy.The quantity m/r plays an important rol...We study the energy issue in critical collapse.It is found that in critical collapse,the contribution from the material energy is greater than that from the gravitational energy.The quantity m/r plays an important role in identifying the formation of an apparent horizon in gravitational collapse,where m is the Misner-Sharp mass and r is the areal radius.We observe that in critical collapse,the maximum value of m/r fluctuates between 2/15 and 4/15.This denotes a large gap between critical collapse and black hole formation for which the criterion is m/r=1/2.展开更多
In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Mank...In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Manko-Novikov black hole spacetime.Aiming to better understand the underlying physics,we elaborate on the boundaries of the accessible region through analyses of the contours of the effective potentials.The latter is associated with the two roots of a quadratic equation.In particular,we explore its interplay with an ergoregion,which leads to specific features of the effective potentials,such as the emergence of a cuspy edge and the formation of a pocket,which serve as static constraints on the geodesics.Additionally,we investigate the properties of the radial and angular accelerations at the turning points in photon trajectories.The accelerations are further examined and may provide kinematic constraints on the geodesics,as argued herein.It is concluded that the onset of the chaotic lensing is significantly related to both con-straints;as a result,an arbitrary slight deviation in the incident photon is significantly amplified during evolution through an extensive period,demonstrating the complexity in the highly nonlinear deterministic gravitational system.展开更多
In this study,we investigate the quasinormal mode and late-time tail of charged massless scalar perturbations of a black hole in generalized Rastall gravity.The black hole metric in question is spherically symmetric,a...In this study,we investigate the quasinormal mode and late-time tail of charged massless scalar perturbations of a black hole in generalized Rastall gravity.The black hole metric in question is spherically symmetric,accompanied by a power-Maxwell field surrounded by a quintessence fluid.We show that the massless scalar field,when dressed up with the magnetic field,acquires an effective mass,which significantly affects the properties of the resultant quasinormal oscillations and late-time tails.Specifically,the quasinormal frequencies become distorted and might even be unstable for particular spacetime configurations.Additionally,the exponent of the usual power-law tail is modified according to the modification in the structure of the branch cut of the retarded Green s function.In particular,as the effective mass is generated dynamically owing to the presence of the magnetic field,we may consider a process through which the field is gradually removed from the spacetime configuration.In this context,while the quasinormal oscillations converge to the case of massless perturbations,we argue that the properties of resultant late-time tails do not fall back to their massless counterpart.The relevant characteristics are investigated using numerical and analytic approaches.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12247150,12305062,12175076,and 11925503)the Post-doctoral Science Foundation of China(Grant No.2022M721257)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001).
文摘Laser interferometry plays a crucial role in laser ranging for high-precision space missions such as GRACE(Gravity Recovery and Climate Experiment)Follow-On-like missions and gravitational wave detectors.For such accuracy of modern space missions,a precise relativistic model of light propagation is required.With the post-Newtonian approximation,we utilize the Synge world function method to study the light propagation in the Earth’s gravitational field,deriving the gravitational delays up to order c^(−4).Then,we investigate the influences of gravitational delays in three inter-satellite laser ranging techniques,including one-way ranging,dual one-way ranging,and transponder-based ranging.By combining the parameters of Kepler orbit,the gravitational delays are expanded up to the order of e^(2)(e is the orbital eccentricity).Finally,considering the GRACE Follow-On-like missions,we estimate the gravitational delays to the level of picometer.The results demonstrate some high-order gravitational and coupling effects,such as c^(−4)-order gravitational delays and coupling of Shapiro and beat frequency,which may be non-negligible for higher precision laser ranging in the future.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11575160,91636221,and 11605065)
文摘In a test of the weak equivalence principle （WEP） with a rotating torsion pendulum, it is important to estimate the amplitude of the modulation signal with high precision. We use a torsional filter to remove the free oscillation signal and employ the correlation method to estimate the amplitude of the modulation signal. The data analysis of an experiment shows that the uncertainties of amplitude components of the modulation signal obtained by the correlation method are in agreement with those due to white noise. The power spectral density of the modulation signal obtained by the correlation method is about one order higher than the thermal noise limit. It indicates that the correlation method is an effective way to estimate the amplitude of the modulation signal and it is instructive to conduct a high-accuracy WEP test.
基金Project supported by the National Natural Science Foundation of China(Grant No.11575160)
文摘In the torsion pendulum experiments, the thermal noise sets the most fundamental limit to the accurate estimation of the amplitude of the signal with known frequency. The variance of the conventional method can meet the limit only when the measurement time is much longer than the relaxation time of the pendulum. By using the maximum likelihood estimation and the equation-of-motion filter operator, we propose an optimal(minimum variance, unbiased) amplitude estimation method without limitation of the measurement time, where thermal fluctuation is the leading noise. While processing the experimental data tests of the Newtonian gravitational inverse square law, the variance of our method has been improved than before and the measurement time of determining the amplitude with this method has been reduced about half than before for the same uncertainty. These results are significant for the torsion experiment when the measurement time is limited.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11575160 and 11805074)the Postdoctoral Science Foundation of China(Grant Nos.2017M620308 and 2018T110750).
文摘In the measurement of the Newtonian gravitational constant G with the time-of-swing method,the influence of the Earth's rotation has been roughly estimated before,which is far beyond the current experimental precision.Here,we present a more complete theoretical modeling and assessment process.To figure out this effect,we use the relativistic Lagrangian expression to derive the motion equations of the torsion pendulum.With the correlation method and typical parameters,we estimate that the influence of the Earth's rotation on G measurement is far less than 1 ppm,which may need to be considered in the future high-accuracy experiments of determining the gravitational constant G.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11625417,11727809,11474115,91636219,and 91636221)the Post-doctoral Science Foundation of China(Grant No.2017M620308)
文摘The effect of the Raman-pulse duration related to the magnetic field gradient, as a systematic error, is playing an important role on evaluating the performance of high-precision atomic gravimeters. We study this effect with a simplified theoretical model of the time-propagation operator. According to the typical parameters, we find that this effect should be taken into account when the gravimeter reaches an accuracy of 10^-10g, and the larger the pulse duration is, the more obvious the systematic effect will be. Finally, we make a simple discussion on the possibility of testing this effect.
基金Supported by the National Natural Science Foundation of China (11925503)the Guangdong Major project of Basic and Applied Basic Research (2019B030302001).
文摘We conduct numerical investigations on the critical collapse of spherically symmetric massless scalar fields in asymptotically anti-de Sitter spacetime.Our primary focus is on the behavior of the critical amplitude under various initial configurations of the scalar field.Through our numerical results,we obtain a formula that determines critical amplitude in terms of cosmological constantΛ:A^(*)∝(0.01360σ/v_(0)+0.001751)Λ,whereσdenotes the initial width of the scalar field and is the initial position of the scalar field.Notably,we highlight that the slope of this linear relationship depends on the initial configuration of the scalar field.
基金supported by the National Natural Science Foundation of China(Grant No.11925503)supported by Shandong Province Natural Science Foundation under grant No.ZR2019MA068.
文摘We study the energy issue in critical collapse.It is found that in critical collapse,the contribution from the material energy is greater than that from the gravitational energy.The quantity m/r plays an important role in identifying the formation of an apparent horizon in gravitational collapse,where m is the Misner-Sharp mass and r is the areal radius.We observe that in critical collapse,the maximum value of m/r fluctuates between 2/15 and 4/15.This denotes a large gap between critical collapse and black hole formation for which the criterion is m/r=1/2.
基金Supported by the National Natural Science Foundation of China(NNSFC,12005077)Guangdong Basic and Applied Basic Research Foundation(2021A1515012374).
文摘In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Manko-Novikov black hole spacetime.Aiming to better understand the underlying physics,we elaborate on the boundaries of the accessible region through analyses of the contours of the effective potentials.The latter is associated with the two roots of a quadratic equation.In particular,we explore its interplay with an ergoregion,which leads to specific features of the effective potentials,such as the emergence of a cuspy edge and the formation of a pocket,which serve as static constraints on the geodesics.Additionally,we investigate the properties of the radial and angular accelerations at the turning points in photon trajectories.The accelerations are further examined and may provide kinematic constraints on the geodesics,as argued herein.It is concluded that the onset of the chaotic lensing is significantly related to both con-straints;as a result,an arbitrary slight deviation in the incident photon is significantly amplified during evolution through an extensive period,demonstrating the complexity in the highly nonlinear deterministic gravitational system.
基金Supported by the National Natural Science Foundation of China(NNSFC)(11805166,11925503,12175076)the financial support from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP)+4 种基金Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro(FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(CAPES)the project Institutos Nacionais de Ciencias e Tecnologia-Fisica Nuclear e Aplicacoes(INCT/FNA)Proc.No.464898/2014-5supported by the Center for Scientific Computing(NCC/Grid UNESP)of the Sao Paulo State University(UNESP)。
文摘In this study,we investigate the quasinormal mode and late-time tail of charged massless scalar perturbations of a black hole in generalized Rastall gravity.The black hole metric in question is spherically symmetric,accompanied by a power-Maxwell field surrounded by a quintessence fluid.We show that the massless scalar field,when dressed up with the magnetic field,acquires an effective mass,which significantly affects the properties of the resultant quasinormal oscillations and late-time tails.Specifically,the quasinormal frequencies become distorted and might even be unstable for particular spacetime configurations.Additionally,the exponent of the usual power-law tail is modified according to the modification in the structure of the branch cut of the retarded Green s function.In particular,as the effective mass is generated dynamically owing to the presence of the magnetic field,we may consider a process through which the field is gradually removed from the spacetime configuration.In this context,while the quasinormal oscillations converge to the case of massless perturbations,we argue that the properties of resultant late-time tails do not fall back to their massless counterpart.The relevant characteristics are investigated using numerical and analytic approaches.
