arXiv subjects

Xia Tiecheng

Publications and source records attributed to Xia Tiecheng.

11 recordsLinked to original sources

arXiv2026

Rényi Entropy and the Topological Features of Charged AdS Black Hole

This study applies Duan's topological current $ϕ$-mapping theory to investigate a newly proposed charged modified AdS black hole using the Rényi entropy formalism, examining its thermodynamic properties across the canonical, mixed, and grand canonical ensembles.} Electric and magnetic charges are fixed in the canonical ensemble, whereas the mixed ensemble incorporates electric and magnetic potentials. The grand canonical ensemble, meanwhile, ensures consistency by employing these potentials exclusively. Initially, we compute topological charges by identifying critical points in each ensemble. In both the canonical and mixed ensembles, we identify a conventional critical point with a topological charge of $-1$. We then model the black hole's domain in the AdS regime as a topological defect in thermodynamic space and analyze its local and global topology by calculating the winding numbers at these defect locations. {Interestingly, the canonical and mixed ensembles exhibit identical black hole topologies, each possessing a total topological charge of $1$ within the framework of the Rényi entropy.} Finally, we characterize the canonical, mixed, and grand canonical ensembles based on the presence of generation/annihilation points: the canonical ensemble has one such point, the mixed ensemble has a negative one, and the grand canonical ensemble has none.

physics.gen-ph↗

arXiv2025

Dark Energy Compact Stars in Extended Teleparallel Gravity

This paper presents the study of dark-energy compact stars in the context of modified Rastall teleparallel gravity. It is the first time that dark energy celestial phenomena have been explored in this modified gravitational theory. Employing the torsion-based functions, $f(T)$ and $h(T)$, we analyzed their effects in a spherically symmetric spacetime chosen as the interior geometry, while using the Schwarzschild geometry as an outer spacetime. In this study, we explored various dark energy stellar properties, including dark energy pressure components, energy conditions, and equation of state components. Our findings reveal that the observed negative behavior of these stellar properties served as compelling evidence, validating the presence of dark energy in stellar configurations. Detailed investigations of the energy conditions, pressure profiles, sound speeds, TOV equation, adiabatic index, gradients, mass function, compactness, and redshift function forecasts a comprehensive assessment, affirming the acceptability and realism of the investigated stellar configuration.

gr-qc↗

arXiv2025

First-order correction of tunneling and entropy in the Horndeski gravity-like hairy black hole

In this work, we apply tunneling formalism to analyze charged particles tunneling across a hairy black hole horizon. Such black hole solutions are essential for frameworks based on Horndeski's gravity theory. Applying a semi-classical technique, we examine the tunneling of charged particles from a hairy black hole and derive the generic tunneling spectrum of released particles, ignoring self-gravitational and interaction. It is studied to ignore the back-reaction impact of the radiated particle on the hairy black hole. We analyze the properties of the black hole, such as temperature and entropy, under the influence of quantum gravity and also observe that the first-order correction is present. We study tunneling radiation produced by a charged field equation in the presence of a generalized uncertainty effect. We modify the semi-classical technique by using the generalized uncertainty principle, the WKB approximation, and surface gravity.

gr-qc↗

arXiv2025

Exploring light deflection and black hole shadows in Rastall theory with plasma effects

In this article, we examine the gravitational deflection of particles in curved spacetime immersed in perfect fluid in the context of Rastall theory. We propose an infinite region approach to Gibbons-Werner to avoid singularity, given that the integral region is generally infinite. In the Rastall theory framework, the black hole solutions in the dust field are studied. Additionally, we check the deflection angle from this spacetime under the influence of plasma. Furthermore, we analytically compute plasma's impact on a black hole shadow using a ray-tracing approach and Hamiltonian equation. Hence, the light ray motion equations are independent of the plasma's velocity. It is assumed that plasma is a dispersive medium, pressureless and non-magnetised, and the plasma particle density corresponds to particle accumulation. The supermassive black hole's shadow and emitted energy are explored when plasma falls radially from infinity onto the black hole.

gr-qc↗

arXiv2025

Evaluation of physical properties of Kiselev like AdS spacetime in the context of $f(R,~T)$ gravity under the impact of quantum gravity

The developments of the $f(R,~T)$ gravity theory, which is a logical expansion of general relativity according to Einstein, inspire us to examine this theory in greater detail and take up our study to obtain a modification of the Kiselev-like AdS black holes scenario. In this study, we employ the semi-classical Hamilton-Jacobi procedure to investigate the Hawking temperature $(T_{H})$ for 4-dimensional Kiselev-like AdS BHs in the context of $f(R,~T)$ gravity. We derive the temperature using a standard formula for Kiselev-like AdS BHs in the context of $f(R,~T)$ gravity. The relativistic field equation in the context of the generalized uncertainty principle (GUP), the semi-classical Hamilton-Jacobi procedure, and the WKB strategy are used to tunnel boson particles into the horizon under the effect of quantum gravity as well as Hawking temperature and also use this temperature to compute entropy corrections. Further, we study the $f(R,~T)$ gravity ($ζ$), quantum gravity ($α$), and particle kinetic energy ($Ξ$) effect on both temperature and entropy.

gr-qc↗

arXiv2025

Study of light deflection and shadow from a hairy black hole under the influence of the non-magnetic plasma

This article computes the bending angle of a hairy black hole at weak field limits. The Gauss-Bonnet theorem is applied to the Gaussian optical curvature; this gives a way to calculate the hairy black hole light bending angle using the Gibbons and Werner approach. We determine the light's deflection angle under the influence of gravitational decoupling parameters, non-magnetic plasma, and dark matter. Further, using the ray tracing phenomenon, we determine the shadow at which light is deflected when a non-magnetic plasma medium is present. There must exist unstable circular light orbits that can act as limit curves for light rays in a spiral motion. In this manner, the shadow can be calculated for an observer at any distance from the center, and the energy emission rate for the hairy black hole can be studied.

gr-qc↗

arXiv2024

Thermal analysis and Joule-Thomson expansion of black hole exhibiting metric-affine gravity

This study examines a recently hypothesized black hole, which is a perfect solution of metric-affine gravity with a positive cosmological constant, and its thermodynamic features as well as the Joule-Thomson expansion. We develop some thermodynamical quantities, such as volume, Gibbs free energy, and heat capacity, using the entropy and Hawking temperature. We also examine the first law of thermodynamics and thermal fluctuations, which might eliminate certain black hole instabilities. In this regard, a phase transition from unstable to stable is conceivable when the first law order corrections are present. Besides that, we study the efficiency of this system as a heat engine and the effect of metric-affine gravity for physical parameters $q_e$, $q_m$, $κ_{\mathrm{s}}$, $κ_{\mathrm{d}}$ and $κ_{\mathrm{sh}}$. Further, we study the Joule-Thomson coefficient, and the inversion temperature and also observed the isenthalpic curves in the $T_i -P_i$ plane. In metric-affine gravity, a comparison is made between the Van der Waals fluid and the black hole to study their similarities and differences.

gr-qc↗

arXiv2023

Joule-Thomson expansion and tidal force effects of AdS black holes surrounded by Chaplygin dark fluid

This study examines a recently hypothesized black hole. We study the Joule-Thomson coefficient, the inversion temperature and also the isenthalpic curves in the $T_i -P_i$ plane. A comparison is made between the Van der Waals fluid and the black hole to study their similarities and differences. The Joule-Thomson coefficient, the inversion curves and the isenthalpic curves are discussed inAdS black holes surrounded by Chaplygin dark fluid. In $T -P$ plane, the inversion temperature curves and isenthalpic curves are obtained with different parameters. Next, we explore the radial timelike geodesics that leads us to explore the tidal force effects for a radially in-falling particle in such black hole spacetime. We also numerically solve the geodesic deviation equation for two nearby radial geodesics for a freely falling particle. Our analysis shows that contrary to the Schwarzschild spacetime, the tidal forces don't become zero at spatial infinity due to the lack of asymptotic flatness because of the presence of a non-zero cosmological constant. The geodesic separation profile shows an oscillating trend and depends on the dynamic spacetime parameters $q, B$ and $Λ$.

gr-qc↗

arXiv2023

Testing new massive conformal gravity with the light deflection by black hole

We study the weak gravitational lensing effect of Non-Bocharova-Bronnikov-Melnikov-Bekenstein (BBMB) black hole in new massive conformal gravity. We analyze the deflection angle of light caused by new massive conformal gravity by using the gauss-bonnet theorem. As a consequence, we obtain the gaussian optical curvature and calculate the deflection angle of the new massive conformal gravity for spherically balanced spacetime with the gauss-bonnet theorem. The resultant deflection angle of light in the weak field limits showing that the bending of light is a global and topological phenomenon. Furthermore, we identify the deflection angle of light in the framework of the plasma medium, we also demonstrate the effect of a plasma medium on the deflection of light by non BBMB. In addition, the behavior of the deflection angle by new massive conformal gravity is explicitly shown in the influence of plasma medium and for the non plasma medium.

gr-qc↗

arXiv2023

Testing the Metric-Affine Gravity Using Particle Dynamics and Photon Motion

This work mainly focuses to unveil the optical features of a black hole. For this objective, we utilize the metric-affine black hole geometry with the inclusion of dilation, spin, and shear charge. The Lagrangian coefficients $f_1$ and $d_1$ are the main parameters, where $f_1<0$, which differentiate the solutions by $d_1=8f_1,\;d_1=-8f_1,\;\&\;d_1=\pm8f_1$. Based on these parameters, we carry out this work in two cases, i.e., $d_1=8f_1,\;\&\;d_1=-8f_1$. We forecast the detailed impact of dilation, spin, and shear charges on the optical properties of the black holes in both cases. To unreveal the optical features, we calculate horizon radius, inner stable circular orbit, photon sphere radius, BH shadows, quasi-periodic oscillations, the red-blue shift of photon particles, effective force, weak gravitational lensing, and image magnification by using metric-affine gravity black hole geometry.

gr-qc↗

arXiv2023

Logarithm Corrections and Thermodynamics for Horndeski gravity like Black Holes

In this paper, we compute the Hawking temperature by applying quantum tunneling approach for the Horndeski like black holes. We utilize the semi-classical phenomenon and WKB approximation to the Lagrangian field equation involving generalized uncertainty principle (GUP) and compute the tunneling rate as well as Hawking temperature. For the zero gravity parameter, we obtain results consistent without correction parameter or original tunneling. Moreover, we study the thermal fluctuations of the considered geometry and examine the stable state of the system by heat capacity technique. We also investigate the behaviour of thermodynamic quantities under the influence of thermal fluctuations. We observe from the graphical analysis, the corresponding system is thermodynamically stable with these correction terms.

gr-qc↗