We investigated the shadow and weak gravitational lensing for the quantum-improved charged black hole(BH).First,the photon motion and BH shadow were studied in a plasma medium.It can be seen from our analysis that the...We investigated the shadow and weak gravitational lensing for the quantum-improved charged black hole(BH).First,the photon motion and BH shadow were studied in a plasma medium.It can be seen from our analysis that the radius of the photon sphere of the quantum-improved charged BH and size of the BH shadow decrease under the influence of the plasma parameter.Furthermore,the gravitational weak lensing is considered for the quantum-improved charged BH,and we have obtained the deflection angle of light rays around a compact object for uniform and non-uniform plasma cases.It is shown that the value of the deflection angle for uniform plasma increases with increasing plasma parameter,and vice versa for non-uniform plasma.It has been also indicated that under the influence of the plasma parameter and BH charge,the values of the deflection angles for the two cases decrease.Finally,we investigated the magnification of image brightness using the deflection angle of the light rays around the quantum-improved charged BH.展开更多
In this study,we investigated the gravitational weak lensing and shadow of the Ellis-Bronnikov wormhole.First,we studied the photon motion in a plasma medium and a wormhole shadow.It was shown that the radius of the p...In this study,we investigated the gravitational weak lensing and shadow of the Ellis-Bronnikov wormhole.First,we studied the photon motion in a plasma medium and a wormhole shadow.It was shown that the radius of the photon sphere of the Ellis-Bronnikov wormhole and the size of the wormhole shadow become larger under the influence of the parameter a.The upper limit of the parameter a in the Ellis-Bronnikov wormhole spacetime was obtained.Second,we investigated the weak gravitational lensing for the Ellis-Bronnikov wormhole and calculated the deflection angle for uniform and non uniform plasma cases.The value of the deflection angle for uniform plasma increased with the increase in plasma parameter value,and vice versa for non uniform plasma.We found that,under the influence of the parameter a,the values of the deflection angles for two cases decreased.Finally,we investigated the magnification of image brightness using the deflection angle of the light rays around the wormhole in the EllisBronnikov theory.展开更多
In this study,we explore the properties of a non-rotating black hole in the Einstein-Maxwell-scalar(EMS)theory and investigate the luminosity of the accretion disk surrounding it.We determine all the orbital parameter...In this study,we explore the properties of a non-rotating black hole in the Einstein-Maxwell-scalar(EMS)theory and investigate the luminosity of the accretion disk surrounding it.We determine all the orbital parameters of particles in the accretion disk,including the radius of the innermost stable circular orbit(ISCO)with angular velocity,angular momentum,and energy.Further,we study the radiative efficiency for different values of black hole parameters.Finally,we analyze the flux,differential luminosity,and temperature of the accretion disk.展开更多
In this study,we investigated the optical properties of charged black holes within the Einstein-Maxwellscalar(EMS)theory.We evaluated the shadow cast by these black holes and obtained analytical solutions for both the...In this study,we investigated the optical properties of charged black holes within the Einstein-Maxwellscalar(EMS)theory.We evaluated the shadow cast by these black holes and obtained analytical solutions for both the radius of the photon sphere and that of the shadow.We observed that black hole parametersγandβboth influence the shadow of black holes.We also found that the photon sphere and shadow radius increase as a consequence of the presence of the parameterγ.Interestingly,the shadow radius decreases first and then remains unchanged owing to the impact of the parameterβ.Finally,we analyzed the weak gravitational lensing and total magnification of lensed images around black holes.We found that the charge of the black holes and the parameterβboth have a significant impact,reducing the deflection angle.Similarly,the same behavior for the total magnification was observed,also as a result of the effect of the charge of the black holes and the parameterβ.展开更多
We study the particle motion around a black hole(BH)in Horava-Lifshitz(HL)gravity with the Kehagias-Sfetsos(KS)parameter.First,the innermost stable circular orbit(ISCO)is obtained for massive particles around the BH i...We study the particle motion around a black hole(BH)in Horava-Lifshitz(HL)gravity with the Kehagias-Sfetsos(KS)parameter.First,the innermost stable circular orbit(ISCO)is obtained for massive particles around the BH in HL gravity.We find that the radii of the ISCOs decrease as the KS parameter decreases,meaning that the parameterΩcauses the orbits of particles to move inward with respect to that of the Schwarzschild BH case.Then,the optical properties of a KS BH are studied in detail,that is,the BH shadow and gravitational weak lensing.We demonstrate that the size of the BH shadow decreases under the influence of the KS parameter.展开更多
基金Supported partly by Grants F-FA-2021-432,F-FA-2021-510,and MRB-2021-527 of the Ministry of Higher Education,Science and Innovations of the Republic of Uzbekistan。
文摘We investigated the shadow and weak gravitational lensing for the quantum-improved charged black hole(BH).First,the photon motion and BH shadow were studied in a plasma medium.It can be seen from our analysis that the radius of the photon sphere of the quantum-improved charged BH and size of the BH shadow decrease under the influence of the plasma parameter.Furthermore,the gravitational weak lensing is considered for the quantum-improved charged BH,and we have obtained the deflection angle of light rays around a compact object for uniform and non-uniform plasma cases.It is shown that the value of the deflection angle for uniform plasma increases with increasing plasma parameter,and vice versa for non-uniform plasma.It has been also indicated that under the influence of the plasma parameter and BH charge,the values of the deflection angles for the two cases decrease.Finally,we investigated the magnification of image brightness using the deflection angle of the light rays around the quantum-improved charged BH.
基金partly Supported by Grants F-FA-2021-432,F-FA-2021-510,and MRB-2021-527 of the Ministry of Higher Education,Science and Innovations of the Republic of Uzbekistan。
文摘In this study,we investigated the gravitational weak lensing and shadow of the Ellis-Bronnikov wormhole.First,we studied the photon motion in a plasma medium and a wormhole shadow.It was shown that the radius of the photon sphere of the Ellis-Bronnikov wormhole and the size of the wormhole shadow become larger under the influence of the parameter a.The upper limit of the parameter a in the Ellis-Bronnikov wormhole spacetime was obtained.Second,we investigated the weak gravitational lensing for the Ellis-Bronnikov wormhole and calculated the deflection angle for uniform and non uniform plasma cases.The value of the deflection angle for uniform plasma increased with the increase in plasma parameter value,and vice versa for non uniform plasma.We found that,under the influence of the parameter a,the values of the deflection angles for two cases decreased.Finally,we investigated the magnification of image brightness using the deflection angle of the light rays around the wormhole in the EllisBronnikov theory.
基金Supported by the National Natural Science Foundation of China (11675143, 11975203)the National Key Research and Development Program of China(2020YFC2201503)。
文摘In this study,we explore the properties of a non-rotating black hole in the Einstein-Maxwell-scalar(EMS)theory and investigate the luminosity of the accretion disk surrounding it.We determine all the orbital parameters of particles in the accretion disk,including the radius of the innermost stable circular orbit(ISCO)with angular velocity,angular momentum,and energy.Further,we study the radiative efficiency for different values of black hole parameters.Finally,we analyze the flux,differential luminosity,and temperature of the accretion disk.
基金Supported by the National Natural Science Foundation of China(11675143)the National Key Research and Development Program of China(2020YFC2201503)the support from Research Grant F-FA-2021-432 of the Ministry of Higher Education,Science and Innovations of the Republic of Uzbekistan。
文摘In this study,we investigated the optical properties of charged black holes within the Einstein-Maxwellscalar(EMS)theory.We evaluated the shadow cast by these black holes and obtained analytical solutions for both the radius of the photon sphere and that of the shadow.We observed that black hole parametersγandβboth influence the shadow of black holes.We also found that the photon sphere and shadow radius increase as a consequence of the presence of the parameterγ.Interestingly,the shadow radius decreases first and then remains unchanged owing to the impact of the parameterβ.Finally,we analyzed the weak gravitational lensing and total magnification of lensed images around black holes.We found that the charge of the black holes and the parameterβboth have a significant impact,reducing the deflection angle.Similarly,the same behavior for the total magnification was observed,also as a result of the effect of the charge of the black holes and the parameterβ.
基金partly supported by Grants F-FA-2021-432,F-FA-2021-510,and MRB-2021-527 of the Ministry of Higher Education,Science and Innovations of the Republic of Uzbekistan
文摘We study the particle motion around a black hole(BH)in Horava-Lifshitz(HL)gravity with the Kehagias-Sfetsos(KS)parameter.First,the innermost stable circular orbit(ISCO)is obtained for massive particles around the BH in HL gravity.We find that the radii of the ISCOs decrease as the KS parameter decreases,meaning that the parameterΩcauses the orbits of particles to move inward with respect to that of the Schwarzschild BH case.Then,the optical properties of a KS BH are studied in detail,that is,the BH shadow and gravitational weak lensing.We demonstrate that the size of the BH shadow decreases under the influence of the KS parameter.
