As a candidate bound for the Binary Black Hole(BBH) merger events detected by LIGO/Virgo, Primordial Black Holes(PBHs)provide a useful tool to investigate the primordial curvature perturbations on small scales. Using ...As a candidate bound for the Binary Black Hole(BBH) merger events detected by LIGO/Virgo, Primordial Black Holes(PBHs)provide a useful tool to investigate the primordial curvature perturbations on small scales. Using the GWTC-1 to GWTC-3 catalogs, under the scenario that PBHs originate from large primordial curvature perturbations on small scales during infiationary epoch, we for the first time reconstruct the power spectrum of primordial curvature perturbations on small scales. It is found that the value of the amplitude of the primordial power spectrum is enhanced to O(10-2)on scales O(1) pc. This may imply the validity of PBH as a possible BBH merger candidate.展开更多
This paper studies the thermodynamic properties of the 5D black hole in Einstein-Gauss-Bonnet gravity from the viewpoint of geometrothermodynamics. It is found that the Legendre invariant metrics of the 5D black holes...This paper studies the thermodynamic properties of the 5D black hole in Einstein-Gauss-Bonnet gravity from the viewpoint of geometrothermodynamics. It is found that the Legendre invariant metrics of the 5D black holes in Einstein-Yang-Mills-Gauss-Bonnet theory and Einstein-Maxwell-Gauss-Bonnet theory reproduce the behavior of the thermodynamic interaction and phase transition structure of the corresponding black hole configurations correctly. It is shown that they are both curved and that the curvature scalar provides information about the phase transition point.展开更多
In this paper, we study the thermodynamic features of a two-dimensional charged black hole. Weinhold curvature and Ruppeiner curvature are explored as information geometry, respectively. Moreover, based on the Legendr...In this paper, we study the thermodynamic features of a two-dimensional charged black hole. Weinhold curvature and Ruppeiner curvature are explored as information geometry, respectively. Moreover, based on the Legendre invariant proposed by Hernando Quevedo, the geometro-thermodynamics behavior of this black hole is investigated.展开更多
In order to solve the hole-filling mismatch problem in virtual view synthesis, a three-step repairing(TSR) algorithm was proposed. Firstly, the image with marked holes is decomposed by the non-subsampled shear wave tr...In order to solve the hole-filling mismatch problem in virtual view synthesis, a three-step repairing(TSR) algorithm was proposed. Firstly, the image with marked holes is decomposed by the non-subsampled shear wave transform(NSST), which will generate high-/low-frequency sub-images with different resolutions. Then the improved Criminisi algorithm was used to repair the texture information in the high-frequency sub-images, while the improved curvature driven diffusion(CDD) algorithm was used to repair the low-frequency sub-images with the image structure information. Finally, the repaired parts of high-frequency and low-frequency sub-images are synthesized to obtain the final image through inverse NSST. Experiments show that the peak signal-to-noise ratio(PSNR) of the TSR algorithm is improved by an average of 2-3 dB and 1-2 dB compared with the Criminisi algorithm and the nearest neighbor interpolation(NNI) algorithm, respectively.展开更多
Understanding the thermodynamic phase transition of black holes can provide a deep insight into the fundamental properties of black hole gravity to establish the theory of quantum gravity.We investigate the condition ...Understanding the thermodynamic phase transition of black holes can provide a deep insight into the fundamental properties of black hole gravity to establish the theory of quantum gravity.We investigate the condition and latent heat of phase transition for non-linear charged AdS black holes using Maxwell's equal-area law.In addition,we analyze the boundary and curve of the two-phase coexistence area in the expanded phase space.We suggest that the phase transition of the non-linear charged AdS black hole with the fixed temperature(T<T_(c))is related to the electric potential at the horizon,not only to the location of black hole horizon.Recently,the molecular number density was introduced to study the phase transition and microstructure of black holes.On this basis,we discuss the continuous phase transition of a non-linear charged AdS black hole to reveal the potential microstructure of a black hole by introducing the order parameter and using the scalar curvature.展开更多
The acceleration mechanism of astrophysical jet and the collimation mechanism narrowing down to a long distance have been examined so far. It is a collimation problem of how to narrow the astrophysical jet narrowly. F...The acceleration mechanism of astrophysical jet and the collimation mechanism narrowing down to a long distance have been examined so far. It is a collimation problem of how to narrow the astrophysical jet narrowly. Further, the model of the astrophysical jet acceleration mechanism is required to solve this collimation problem at the same time as well as its acceleration. At the present time, the magnetic force model （magnetic centrifugal force and magnetic pressure） is regarded as the most dominant theory which solves the two problems of astrophysical jet acceleration and collimation at the same time. In addition to the present astrophysical jet narrow collimation mechanism by magnetic tension （pinch） force, in this article, another collimation mechanism which narrows down an astrophysical jet is newly introduced. That is, since a curvature is generated in the space around the astrophysical jet by magnetic field, a kind of pressure equivalent to the gravitational effect is generated in the direction of the interior of astrophysical jet as well as the pinch force from the outer circumferential surface of the astrophysical jet.展开更多
基金the support from JSPS Grant-in-Aid for Scientific Research (Grant Nos. JP18K18764, JP21H01080, and JP21H00069)the Fundamental Research Funds for the Central Universities。
文摘As a candidate bound for the Binary Black Hole(BBH) merger events detected by LIGO/Virgo, Primordial Black Holes(PBHs)provide a useful tool to investigate the primordial curvature perturbations on small scales. Using the GWTC-1 to GWTC-3 catalogs, under the scenario that PBHs originate from large primordial curvature perturbations on small scales during infiationary epoch, we for the first time reconstruct the power spectrum of primordial curvature perturbations on small scales. It is found that the value of the amplitude of the primordial power spectrum is enhanced to O(10-2)on scales O(1) pc. This may imply the validity of PBH as a possible BBH merger candidate.
基金Supported by Scientific and Technological Foundation of Chongqing Municipal Education Commission (KJ100706)
文摘This paper studies the thermodynamic properties of the 5D black hole in Einstein-Gauss-Bonnet gravity from the viewpoint of geometrothermodynamics. It is found that the Legendre invariant metrics of the 5D black holes in Einstein-Yang-Mills-Gauss-Bonnet theory and Einstein-Maxwell-Gauss-Bonnet theory reproduce the behavior of the thermodynamic interaction and phase transition structure of the corresponding black hole configurations correctly. It is shown that they are both curved and that the curvature scalar provides information about the phase transition point.
文摘In this paper, we study the thermodynamic features of a two-dimensional charged black hole. Weinhold curvature and Ruppeiner curvature are explored as information geometry, respectively. Moreover, based on the Legendre invariant proposed by Hernando Quevedo, the geometro-thermodynamics behavior of this black hole is investigated.
基金supported by the National Natural Science Foundation of China (61834005, 61772417, 61602377, 61634004,61802304)the Shaanxi Province Key R&D Plan (2021GY-029)。
文摘In order to solve the hole-filling mismatch problem in virtual view synthesis, a three-step repairing(TSR) algorithm was proposed. Firstly, the image with marked holes is decomposed by the non-subsampled shear wave transform(NSST), which will generate high-/low-frequency sub-images with different resolutions. Then the improved Criminisi algorithm was used to repair the texture information in the high-frequency sub-images, while the improved curvature driven diffusion(CDD) algorithm was used to repair the low-frequency sub-images with the image structure information. Finally, the repaired parts of high-frequency and low-frequency sub-images are synthesized to obtain the final image through inverse NSST. Experiments show that the peak signal-to-noise ratio(PSNR) of the TSR algorithm is improved by an average of 2-3 dB and 1-2 dB compared with the Criminisi algorithm and the nearest neighbor interpolation(NNI) algorithm, respectively.
基金the Natural Science Foundation of China(11705106,11475108,12075143)the Natural Science Foundation of Shanxi Province,China(201901D111315)+2 种基金the Natural Science Foundation for Young Scientists of Shanxi Province,China(201901D211441)the Scientific Innovation Foundation of the Higher Education Institutions of Shanxi Province(2020L0471,2020L0472)the Science Technology Plan Project of Datong City,China(2020153)。
文摘Understanding the thermodynamic phase transition of black holes can provide a deep insight into the fundamental properties of black hole gravity to establish the theory of quantum gravity.We investigate the condition and latent heat of phase transition for non-linear charged AdS black holes using Maxwell's equal-area law.In addition,we analyze the boundary and curve of the two-phase coexistence area in the expanded phase space.We suggest that the phase transition of the non-linear charged AdS black hole with the fixed temperature(T<T_(c))is related to the electric potential at the horizon,not only to the location of black hole horizon.Recently,the molecular number density was introduced to study the phase transition and microstructure of black holes.On this basis,we discuss the continuous phase transition of a non-linear charged AdS black hole to reveal the potential microstructure of a black hole by introducing the order parameter and using the scalar curvature.
文摘The acceleration mechanism of astrophysical jet and the collimation mechanism narrowing down to a long distance have been examined so far. It is a collimation problem of how to narrow the astrophysical jet narrowly. Further, the model of the astrophysical jet acceleration mechanism is required to solve this collimation problem at the same time as well as its acceleration. At the present time, the magnetic force model （magnetic centrifugal force and magnetic pressure） is regarded as the most dominant theory which solves the two problems of astrophysical jet acceleration and collimation at the same time. In addition to the present astrophysical jet narrow collimation mechanism by magnetic tension （pinch） force, in this article, another collimation mechanism which narrows down an astrophysical jet is newly introduced. That is, since a curvature is generated in the space around the astrophysical jet by magnetic field, a kind of pressure equivalent to the gravitational effect is generated in the direction of the interior of astrophysical jet as well as the pinch force from the outer circumferential surface of the astrophysical jet.
