arXiv subjects

Jian-Hua Shi

Publications and source records attributed to Jian-Hua Shi.

4 recordsLinked to original sources

arXiv2026

Photon Spheres and shadow of Schwarzschild black hole on the EUP framework

An explicit correspondence is established between the Extended Uncertainty Principle (EUP) and the metric function by directly relating the radiation temperature function modified by EUP to the modified spacetime metric. Utilising this modified metric, we subsequently derive the corresponding thermodynamic quantities of the black hole, and calculate the photon sphere radius and the size of the black hole shadow. The results of the study indicate that, in comparison with Schwarzschild black holes, the position of the event horizon remains constant under EUP modifications. However, the photon sphere radius increases with growing EUP parameters, while the shadow size decreases with increasing parameters, demonstrating that EUP induces optical shift phenomena. By comparing with observations of the galactic centre black hole $\text{Sgr}{\text{A}^{*}}$ from the Event Horizon Telescope, new constraints are established on EUP parameters.

gr-qc↗

arXiv2025

Universal relations with the non-extensive entropy in the RPS and CFT framework

In this paper, an in-depth investigation of the thermodynamic relations for AdS Reissner-Nordstr$\ddot{o}$m black holes immersed in perfect fluid dark matter (PFDM) is presented. This investigation is conducted within both the restricted phase space (RPS) and the conformal field theory (CFT) frameworks. The influence of non-extensive forms of entropy is also systematically examined. Our results demonstrate that the Goon-Penco (GP) relation for charged AdS black holes holds within both the RPS and CFT frameworks, irrespective of the specific form of entropy modification. The conclusion of the present study demonstrates that the GP relation constitutes a universal thermodynamic relation.

hep-th↗

arXiv2025

Regular black holes and reductions of thermodynamic phase spaces

The thermodynamic inconsistency observed in regular black holes is resolved through the framework of reduced thermodynamic phase spaces. We demonstrate that regular black holes are essentially induced from singular black holes by adding an extra requirement, which imposes a constraint among black hole parameters. This constraint reduces the thermodynamic phase space, rendering the standard form of the first law of black hole thermodynamics inapplicable. Accordingly, we propose a novel methodology to study the thermodynamic properties of regular black holes. Thermodynamic quantities must be defined in the full, unconstrained thermodynamic phase space of the underlying singular black holes, only afterward is the constraint imposed to derive the consistent and meaningful thermodynamic quantities of the regular black holes. Crucially, this framework extends beyond regular black holes and applies universally to any black hole with this kind of constraint.

gr-qc↗

arXiv2025

Thermodynamic relation on rotating charged black strings with arbitrary cosmological constant

The Goon-Penco (GP) relation was investigated on rotating charged black strings with an arbitrary cosmological constant. It has been demonstrated that the GP relation retains its form in the context of spacetimes described by cylindrical coordinates. In addition, the GP relation is derived in scenarios where the energy state parameters (including angular momentum $J$ and charge $Q$, etc.) are expressed as functions of the perturbation parameter $η$. This finding indicates that the GP relation is not only valid for spacetimes described by spherically symmetric coordinates, but also prevalent for non-spherically symmetric spacetimes, such as cylindrical coordinates. Therefore, the present study demonstrated that the GP relation is universal for spacetimes with arbitrary cosmological constants, irrespective of the adopted coordinate system.

hep-th↗