One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EM-RIs).This task is particularly challenging because EMRI signals are complex,lengthy,and fai...One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EM-RIs).This task is particularly challenging because EMRI signals are complex,lengthy,and faint.In this work,we introduce a 2-layer convolutional neural network(CNN)approach to detect EMRI signals for space-borne detectors,achieving a true positive rate(TPR)of 96.9%at a 1%false positive rate(FPR)for signal-to-noise ratio(SNR)from 50 to 100.Especially,the key intrinsic parameters of EMRIs such as the mass,spin of the supermassive black hole(SMBH)and the initial eccentricity of the orbit can also be inferred directly by employing a neural network.The mass and spin of the SMBH can be determined at 99%and 92%respectively.This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter estimation.Our model also has a low dependency on the accuracy of the waveform model.This study underscores the potential of deep learning methods in EMRI data analysis,enabling the rapid detection of EMRI signals and efficient parameter estimation.展开更多
Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic system.However,there is no effective method to study thermodynamic nature ...Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic system.However,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of state.Aiming at these coexistence states,in this work,we develop a general approach by introducing two new ratio parameters.The first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule number.We demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase transition.The study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and 1.These results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.展开更多
In this work,we investigate the numerical evolution of massive Kaluza–Klein(KK)modes of a Dirac field on a thick brane.We deduce the Dirac equation in five-dimensional spacetime,and obtain the time-dependent evolutio...In this work,we investigate the numerical evolution of massive Kaluza–Klein(KK)modes of a Dirac field on a thick brane.We deduce the Dirac equation in five-dimensional spacetime,and obtain the time-dependent evolution equation and Schr?dinger-like equation of the extradimensional component.We use the Dirac KK resonances as the initial data and study the corresponding dynamics.By monitoring the decay law of the left-and right-chiral KK resonances,we compute the corresponding lifetimes and find that there could exist long-lived KK modes on the brane.Especially,for the lightest KK resonance with a large coupling parameter and a large three momentum,it will have an extremely long lifetime.展开更多
Understanding the dynamic process of black hole thermodynamic phase transitions at a triple point is a huge challenge. In this paper, we conduct the first investigation of dynamic phase behavior at a black hole triple...Understanding the dynamic process of black hole thermodynamic phase transitions at a triple point is a huge challenge. In this paper, we conduct the first investigation of dynamic phase behavior at a black hole triple point. By numerically solving the Smoluchowski equation near the triple point for a six-dimensional charged Gauss-Bonnet anti-de Sitter black hole, we report that initial small, intermediate, or large black holes can transit to the other two coexistent phases at the triple point, indicating that thermodynamic phase transitions can indeed occur dynamically. More significantly, we observe characteristic weak and strong oscillatory behavior in this dynamic process, which can be understood from an investigation of the rate of first passage from one phase to another. Our results further an understanding of the dynamic process of black hole thermodynamic phase transitions.展开更多
In this study, we investigate the entropies of photons, ideal gas-like dust(baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we ca...In this study, we investigate the entropies of photons, ideal gas-like dust(baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and conditions, the entropies of these components can satisfy the second law of thermodynamics independently. Our calculations show that the specific entropy of matter cannot be a constant during the expansion of the universe, except for photons. When these components interact with the space-time background, particle production(annihilation) can occur. We study the influence of the interaction on the entropies of these components and obtain the conditions guaranteeing that the entropy of each component satisfies the second law of thermodynamics.展开更多
Black hole, a strange object of extreme gravity, is gradually believed to be a thermodynamic system after 1972. The area and the surface gravity of black hole event horizon were found to be closely related with the en...Black hole, a strange object of extreme gravity, is gradually believed to be a thermodynamic system after 1972. The area and the surface gravity of black hole event horizon were found to be closely related with the entropy and Hawking temperature. Then four thermodynamic laws were established [1]. Black hole phase transition as a characteristic nature and microstructure indicator has attracted a lot of attention.展开更多
Ruppeiner geometry has been successfully applied in the study of the black hole microstructure by combining with the small-large black hole phase transition,and the potential interactions among the molecular-like cons...Ruppeiner geometry has been successfully applied in the study of the black hole microstructure by combining with the small-large black hole phase transition,and the potential interactions among the molecular-like constituent degrees of freedom are uncovered.In this paper,we will extend the study to the triple point,where three black hole phases coexist acting as a typical feature of black hole systems quite different from the small-large black hole phase transition.For the six-dimensional charged Gauss-Bonnet anti-de Sitter black hole,we thoroughly investigate the swallow tail behaviors of the Gibbs free energy and the equal area laws.After obtaining the black hole triple point in a complete parameter space,we exhibit its phase structures both in the pressure-temperature and temperature-horizon radius diagrams.Quite different from the liquid-vapor phase transition,a double peak behavior is present in the temperature-horizon radius phase diagram.Then we construct the Ruppeiner geometry and calculate the corresponding normalized curvature scalar.Near the triple point,we observe multiple negatively divergent behaviors.Positive curvature scalar is observed for the small black hole with high temperature,which indicates that the repulsive interaction dominates among the microstructure.Furthermore,we consider the variation of the curvature scalar along the coexisting intermediate and large black hole curves.Combining with the observation for different fluids,the result suggests that this black hole system behaves more like the argon or methane.Our study provides a first and preliminary step towards understanding black hole microstructure near the triple point,as well as uncovering the particular properties of the Gauss-Bonnet gravity.展开更多
Considering the quantum electrodynamics(QED)effect,we study the phase transition and Ruppeiner geometry of Euler-Heisenberg anti-de Sitter black holes in the extended phase space.For negative and small positive QED pa...Considering the quantum electrodynamics(QED)effect,we study the phase transition and Ruppeiner geometry of Euler-Heisenberg anti-de Sitter black holes in the extended phase space.For negative and small positive QED parameters,we observe a small/large black hole phase transition and reentrant phase transition,respectively,whereas a large positive value of the QED parameter ruins the phase transition.Phase diagrams for each case are explicitly shown.Then,we construct the Ruppeiner geometry in thermodynamic parameter space.Different features of the corresponding scalar curvature are shown for both the small/large black hole phase transition and reentrant phase transition cases.Of particular interest is the additional region of positive scalar curvature,indicating a dominant repulsive interaction among black hole microstructures,for the black hole with a small positive QED parameter.Furthermore,universal critical phenomena are observed for the scalar curvature of Ruppeiner geometry.These results indicate that the QED parameter has a crucial influence on the black hole phase transition and microstructure.展开更多
For the stochastic gravitational wave backgrounds(SGWBs)search centred at the milli-Hz band,the galactic foreground produced by white dwarf binaries(WDBs)within the Milky Way contaminates the extra-galactic signal sev...For the stochastic gravitational wave backgrounds(SGWBs)search centred at the milli-Hz band,the galactic foreground produced by white dwarf binaries(WDBs)within the Milky Way contaminates the extra-galactic signal severely.Because of the anisotropic distribution pattern of the WDBs and the motion of the space-borne gravitational wave interferometer constellation,the time-domain data stream will show an annual modulation.This property is fundamentally diferent from those of the SGWBs.In this article,we propose a new filtering method for the data vector based on the annual modulation phenomenon.We apply the resulted inverse variance filter to the LISA Data Challenge.The result shows that for the weaker SGWB signal,such as energy density Ω_(astro)=1×10^(-12),the filtering method can enhance the posterior distribution peak prominently.For the stronger signal,such as Ω_(astro)=3×10^(-12),the method can improve the Bayesian evidence from“substantial”to“strong”against null hypotheses.This method is model-independent and self-contained.It does not ask for other types of information besides the gravitational wave data.展开更多
We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its...We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase space.Owing to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific heat.Furthermore,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM.Through the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and pressure.We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal systems.This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.展开更多
The destruction of a regular black hole event horizon might provide us the possibility to access regions inside black hole event horizon.This paper investigates the possibility of overcharging a charged Taub-NUT regul...The destruction of a regular black hole event horizon might provide us the possibility to access regions inside black hole event horizon.This paper investigates the possibility of overcharging a charged Taub-NUT regular black hole via the scattering of a charged field and the absorption of a charged particle.For the charged scalar field scattering,both the near-extremal and extremal charged Taub-NUT regular black holes cannot be overcharged.For the test charged particle absorption,the result shows that the event horizon of the extremal charged Taub-NUT regular black hole still exists while the event horizon of the near-extremal one can be destroyed.However,if the charge and energy cross the event horizon in a continuous path,the near-extremal charged Taub-NUT regular black hole might not be overcharged.展开更多
We derive an exact solution for a spherically symmetric Bardeen black hole surrounded by perfect fluid dark matter(PFDM).By treating the magnetic charge g and dark matter parameter a as thermodynamic variables,we find...We derive an exact solution for a spherically symmetric Bardeen black hole surrounded by perfect fluid dark matter(PFDM).By treating the magnetic charge g and dark matter parameter a as thermodynamic variables,we find that the first law of thermodynamics and the corresponding Smarr formula are satisfied.The thermodynamic stability of the black hole is also studied.The results show that there exists a critical radius r+C where the heat capacity diverges,suggesting that the black hole is thermodynamically stable in the range 0 <r+<r+C. In addition,the critical radius r+C increases with the magnetic charge g and decreases with the dark matter parameter a.Applying the Newman-Janis algorithm,we generalize the spherically symmetric solution to the corresponding rotating black hole.With the metric at hand,the horizons and ergospheres are studied.It turns out that for a fixed dark matter parameter a,in a certain range,with the increase of the rotation parameter a and magnetic charge g,the Cauchy horizon radius increases while the event horizon radius decreases.Finally,we investigate the energy extraction by the Penrose process in a rotating Bardeen black hole surrounded by PFDM.展开更多
A numerical study has indicated that there exists a relation between the quasinormal modes and the Davies point for a black hole.In this paper,we analytically study this relation for charged Reissner-Nordstrom black h...A numerical study has indicated that there exists a relation between the quasinormal modes and the Davies point for a black hole.In this paper,we analytically study this relation for charged Reissner-Nordstrom black holes in asymptotically flat and de Sitter(dS)spacetimes in the eikonal limit,under which the quasinormal modes can be obtained from the null geodesics using the angular velocity Ω and the Lyapunov exponentλof the photon sphere.Both in asymptotically flat and dS spacetimes,we observe spiral-like shapes in the complex quasinormal mode plane.However,the starting point of the shapes does not coincide with the Davies point.Nevertheless,we find a new relation in which the Davies point exactly meets the maximum temperature T in the T-Ω and T-λ planes.In a higher-dimensional asymptotically flat spacetime,although there is no spiral-like shape,such a relation still holds.Therefore,we provide a new relation between black hole thermodynamics and dynamics in the eikonal limit.Applying this relation,we can test the thermodynamic property of a black hole using the quasinormal modes.展开更多
基金supported by the National Key R&D Program of China(Grant No.2021YFC2203002)the National Natural Science Foundation of China(Grant Nos.12173071,and 12473075)。
文摘One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EM-RIs).This task is particularly challenging because EMRI signals are complex,lengthy,and faint.In this work,we introduce a 2-layer convolutional neural network(CNN)approach to detect EMRI signals for space-borne detectors,achieving a true positive rate(TPR)of 96.9%at a 1%false positive rate(FPR)for signal-to-noise ratio(SNR)from 50 to 100.Especially,the key intrinsic parameters of EMRIs such as the mass,spin of the supermassive black hole(SMBH)and the initial eccentricity of the orbit can also be inferred directly by employing a neural network.The mass and spin of the SMBH can be determined at 99%and 92%respectively.This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter estimation.Our model also has a low dependency on the accuracy of the waveform model.This study underscores the potential of deep learning methods in EMRI data analysis,enabling the rapid detection of EMRI signals and efficient parameter estimation.
基金supported by the National Natural Science Foundation of China(Grant Nos.12075103,11875151,and 12247101)the Major Science and Technology Projects of Gansu Province。
文摘Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic system.However,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of state.Aiming at these coexistence states,in this work,we develop a general approach by introducing two new ratio parameters.The first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule number.We demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase transition.The study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and 1.These results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC2201503)the National Natural Science Foundation of China(Grants No.12105126,No.11875151,and No.12247101)+3 种基金the 111Project under(Grant No.B20063)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky2021-pd08)the China Postdoctoral Science Foundation(Grant No.2021M701531)‘Lanzhou City’s scientific research funding subsidy to Lanzhou University’。
文摘In this work,we investigate the numerical evolution of massive Kaluza–Klein(KK)modes of a Dirac field on a thick brane.We deduce the Dirac equation in five-dimensional spacetime,and obtain the time-dependent evolution equation and Schr?dinger-like equation of the extradimensional component.We use the Dirac KK resonances as the initial data and study the corresponding dynamics.By monitoring the decay law of the left-and right-chiral KK resonances,we compute the corresponding lifetimes and find that there could exist long-lived KK modes on the brane.Especially,for the lightest KK resonance with a large coupling parameter and a large three momentum,it will have an extremely long lifetime.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12075103, 11675064, 11875151, and 12047501)the Natural Sciences and Engineering Research Council of Canada。
文摘Understanding the dynamic process of black hole thermodynamic phase transitions at a triple point is a huge challenge. In this paper, we conduct the first investigation of dynamic phase behavior at a black hole triple point. By numerically solving the Smoluchowski equation near the triple point for a six-dimensional charged Gauss-Bonnet anti-de Sitter black hole, we report that initial small, intermediate, or large black holes can transit to the other two coexistent phases at the triple point, indicating that thermodynamic phase transitions can indeed occur dynamically. More significantly, we observe characteristic weak and strong oscillatory behavior in this dynamic process, which can be understood from an investigation of the rate of first passage from one phase to another. Our results further an understanding of the dynamic process of black hole thermodynamic phase transitions.
基金Supported by the National Natural Science Foundation of China (11875151,12047501,11873001,12047564)Lanzhou City’s scientific research funding subsidy to Lanzhou Universitythe Postdoctoral Science Foundation of Chongqing (cstc2021jcyj-bsh0124)
文摘In this study, we investigate the entropies of photons, ideal gas-like dust(baryonic matter), and a special kind of dark energy in the context of cosmology. When these components expand freely with the universe, we calculate the entropy and specific entropy of each component from the perspective of statistics. Under specific assumptions and conditions, the entropies of these components can satisfy the second law of thermodynamics independently. Our calculations show that the specific entropy of matter cannot be a constant during the expansion of the universe, except for photons. When these components interact with the space-time background, particle production(annihilation) can occur. We study the influence of the interaction on the entropies of these components and obtain the conditions guaranteeing that the entropy of each component satisfies the second law of thermodynamics.
基金supported in part by the National Natural Science Foundation of China (11675064 and 11875151)the Fundamental Research Funds for the Central Universities (lzujbky-2019-ct06 and lzujbky-2018-k11).
文摘Black hole, a strange object of extreme gravity, is gradually believed to be a thermodynamic system after 1972. The area and the surface gravity of black hole event horizon were found to be closely related with the entropy and Hawking temperature. Then four thermodynamic laws were established [1]. Black hole phase transition as a characteristic nature and microstructure indicator has attracted a lot of attention.
基金supported by the National Natural Science Foundation of China(Grants No.12075103,No.11675064,No.11875151,and No.12047501)the 111 Project(Grant No.B20063)the Fundamental Research Funds for the Central Universities(No.Lzujbky-2019-ct06)
文摘Ruppeiner geometry has been successfully applied in the study of the black hole microstructure by combining with the small-large black hole phase transition,and the potential interactions among the molecular-like constituent degrees of freedom are uncovered.In this paper,we will extend the study to the triple point,where three black hole phases coexist acting as a typical feature of black hole systems quite different from the small-large black hole phase transition.For the six-dimensional charged Gauss-Bonnet anti-de Sitter black hole,we thoroughly investigate the swallow tail behaviors of the Gibbs free energy and the equal area laws.After obtaining the black hole triple point in a complete parameter space,we exhibit its phase structures both in the pressure-temperature and temperature-horizon radius diagrams.Quite different from the liquid-vapor phase transition,a double peak behavior is present in the temperature-horizon radius phase diagram.Then we construct the Ruppeiner geometry and calculate the corresponding normalized curvature scalar.Near the triple point,we observe multiple negatively divergent behaviors.Positive curvature scalar is observed for the small black hole with high temperature,which indicates that the repulsive interaction dominates among the microstructure.Furthermore,we consider the variation of the curvature scalar along the coexisting intermediate and large black hole curves.Combining with the observation for different fluids,the result suggests that this black hole system behaves more like the argon or methane.Our study provides a first and preliminary step towards understanding black hole microstructure near the triple point,as well as uncovering the particular properties of the Gauss-Bonnet gravity.
基金Supported by the National Natural Science Foundation of China(12075103,11675064,12047501)the 111 Project(B20063)。
文摘Considering the quantum electrodynamics(QED)effect,we study the phase transition and Ruppeiner geometry of Euler-Heisenberg anti-de Sitter black holes in the extended phase space.For negative and small positive QED parameters,we observe a small/large black hole phase transition and reentrant phase transition,respectively,whereas a large positive value of the QED parameter ruins the phase transition.Phase diagrams for each case are explicitly shown.Then,we construct the Ruppeiner geometry in thermodynamic parameter space.Different features of the corresponding scalar curvature are shown for both the small/large black hole phase transition and reentrant phase transition cases.Of particular interest is the additional region of positive scalar curvature,indicating a dominant repulsive interaction among black hole microstructures,for the black hole with a small positive QED parameter.Furthermore,universal critical phenomena are observed for the scalar curvature of Ruppeiner geometry.These results indicate that the QED parameter has a crucial influence on the black hole phase transition and microstructure.
基金supported by the National Key R&D Program of China(Grant Nos.2021YFC2203001,and 2021YFC2203003)National Natural Science Foundation of China(Grant No.12247101)。
文摘For the stochastic gravitational wave backgrounds(SGWBs)search centred at the milli-Hz band,the galactic foreground produced by white dwarf binaries(WDBs)within the Milky Way contaminates the extra-galactic signal severely.Because of the anisotropic distribution pattern of the WDBs and the motion of the space-borne gravitational wave interferometer constellation,the time-domain data stream will show an annual modulation.This property is fundamentally diferent from those of the SGWBs.In this article,we propose a new filtering method for the data vector based on the annual modulation phenomenon.We apply the resulted inverse variance filter to the LISA Data Challenge.The result shows that for the weaker SGWB signal,such as energy density Ω_(astro)=1×10^(-12),the filtering method can enhance the posterior distribution peak prominently.For the stronger signal,such as Ω_(astro)=3×10^(-12),the method can improve the Bayesian evidence from“substantial”to“strong”against null hypotheses.This method is model-independent and self-contained.It does not ask for other types of information besides the gravitational wave data.
基金Supported by the National Natural Science Foundation of China(11875151,12347177,12247101)the 111 Project under(B20063)the Lanzhou City's Scientific Research Funding Subsidy to Lanzhou University。
文摘We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase space.Owing to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific heat.Furthermore,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM.Through the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and pressure.We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal systems.This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875151,and 11522541)the Fundamental Research Funds for the Central Universities(Grant Nos.lzujbky2019-it21,and lzujbky-2019-ct06)。
文摘The destruction of a regular black hole event horizon might provide us the possibility to access regions inside black hole event horizon.This paper investigates the possibility of overcharging a charged Taub-NUT regular black hole via the scattering of a charged field and the absorption of a charged particle.For the charged scalar field scattering,both the near-extremal and extremal charged Taub-NUT regular black holes cannot be overcharged.For the test charged particle absorption,the result shows that the event horizon of the extremal charged Taub-NUT regular black hole still exists while the event horizon of the near-extremal one can be destroyed.However,if the charge and energy cross the event horizon in a continuous path,the near-extremal charged Taub-NUT regular black hole might not be overcharged.
基金the National Natural Science Foundation of China(11571342)。
文摘We derive an exact solution for a spherically symmetric Bardeen black hole surrounded by perfect fluid dark matter(PFDM).By treating the magnetic charge g and dark matter parameter a as thermodynamic variables,we find that the first law of thermodynamics and the corresponding Smarr formula are satisfied.The thermodynamic stability of the black hole is also studied.The results show that there exists a critical radius r+C where the heat capacity diverges,suggesting that the black hole is thermodynamically stable in the range 0 <r+<r+C. In addition,the critical radius r+C increases with the magnetic charge g and decreases with the dark matter parameter a.Applying the Newman-Janis algorithm,we generalize the spherically symmetric solution to the corresponding rotating black hole.With the metric at hand,the horizons and ergospheres are studied.It turns out that for a fixed dark matter parameter a,in a certain range,with the increase of the rotation parameter a and magnetic charge g,the Cauchy horizon radius increases while the event horizon radius decreases.Finally,we investigate the energy extraction by the Penrose process in a rotating Bardeen black hole surrounded by PFDM.
基金Supported by the National Natural Science Foundation of China(11675064,11875151,11522541)the Fundamental Research Funds for the Central Universities(lzujbky-2019-it21)Supported by the Chinese Scholarship Council(CSC)Scholarship(201806185016)to visit the University of Waterloo。
文摘A numerical study has indicated that there exists a relation between the quasinormal modes and the Davies point for a black hole.In this paper,we analytically study this relation for charged Reissner-Nordstrom black holes in asymptotically flat and de Sitter(dS)spacetimes in the eikonal limit,under which the quasinormal modes can be obtained from the null geodesics using the angular velocity Ω and the Lyapunov exponentλof the photon sphere.Both in asymptotically flat and dS spacetimes,we observe spiral-like shapes in the complex quasinormal mode plane.However,the starting point of the shapes does not coincide with the Davies point.Nevertheless,we find a new relation in which the Davies point exactly meets the maximum temperature T in the T-Ω and T-λ planes.In a higher-dimensional asymptotically flat spacetime,although there is no spiral-like shape,such a relation still holds.Therefore,we provide a new relation between black hole thermodynamics and dynamics in the eikonal limit.Applying this relation,we can test the thermodynamic property of a black hole using the quasinormal modes.
