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Wen-Xiang Chen

Publications and source records attributed to Wen-Xiang Chen.

48 records · Page 3Linked to original sources
arXiv2023

Calculating the Hawking Temperatures of Kerr-Newman Black Holes in the f(R) Gravity Models with the RVB Method

In this study, we conducted a comparison between the RVB method and the conventional method discussed in previous literature for calculating the Hawking temperature of Kerr-Newman black holes under f(R) gravity\cite{9,10,11}. Our research findings are in agreement with the results presented in the literature\cite{17}, with only a variation in the integration constant. Through the comparison of these two methods, we arrived at consistent conclusions.After conducting a thorough comparison between the RVB method and the temperature Green's function method, we have found that these two approaches are fundamentally identical. This significant finding highlights the high level of consistency between the temperature Green's function method and the RVB method.

physics.gen-ph↗
arXiv2023

Schwarzschild black hole can also produce super-radiation phenomena under f(R) Gravity and the cosmic censorship conjecture may be violated

This article suggests that Bose-Einstein condensation can occur without the need for an energy barrier when the boundary conditions are set as $\frac{T}{T_{c}}=z$ (where z is a positive integer). Under these conditions, bosons can condense in the Schwarzschild black hole. The incident waves can then be trapped and condensed within the black hole, generating a potential barrier near the event horizon. This suggests that Schwarzschild black holes under f(R) Gravity can also exhibit superradiance, which raises the possibility of violating the cosmic censorship conjecture. It should be noted that the natural unit system is used in this article.

physics.gen-ph↗
arXiv2023

Wormhole Stability of Charged Black Holes Under the Gravity of f(R)

In this paper, we propose that since Hawking radiation may be a kind of superradiation, the action of superradiation with preset bounds satisfies some higher-dimensional action structure, e.g., bosons in the preset springs of Kerr black hole. The superradiation meets the algebraic system of bosons on Kerr-Schild black holes. We think that the superradiation of bounded fermions to Kerr structure black holes benefits the mapping structure of wormholes. By analogy, we find the entropy algebraic expression of the wormhole in the charged black hole under f(R) gravity and then conduct thermodynamic geometric analysis to find out the stability condition of the wormhole.

physics.gen-ph↗
arXiv2022

The superradiant stability of Kerr-Newman black holes

In this article, the superradiation stability of Kerr-Newman black holes is discussed by introducing the condition used in Kerr black holes y into them. Moreover, the motion equation of the minimal coupled scalar perturbation in a Kerr-Newman black hole is divided into angular and radial parts. Hod proved\cite{12} that the Kerr black hole should be superradiantly stable under massive scalar perturbation when $μ\ge \sqrt{2}mΩ_H$, where $μ$ is the mass. In this article, a new variable y is added here to expand the results of the above article. When $\sqrt{2(a^2+Q^2)}/{r^2_+}< ω< m\varOmega_H+q\varPhi_H$,particularly $μ\ge \sqrt{2}(m\varOmega_H+q\varPhi_H)$,so the Kerr-Newman black hole is superradiantly stable at that time.

gr-qc↗
arXiv2022

Thermodynamic geometry analysis of new Schwarzschild black holes

This article puts forward a hypothesis.In this article, the derivative of the cosmological constant is positive, and there is a possibility that the constant evolves from negative in the early universe to positive in the later period. We see that when the black hole is an extreme black hole $r_{+}=r_{-}$, the curvature scalar vanishes to zero. In general, the curvature scalar is not equal to zero. When $r_{+}=3 r_{-}$, the curvature scalar is equal to negative infinity. According to Ruppeiner's theory, this time represents the phase transition of the system. It is very interesting that the divergence point of the curvature scalar happens to be the Davis transition point. We have found the phase transition point of the new Schwarzschild black hole.

gr-qc↗
arXiv2022

Thermodynamic geometric analysis of BTZ black hole in f(R,ϕ) Gravity

In this work, we obtain the thermodynamic geometry of the extended black hole solution under f(R) gravity. This is the foundation of our work. We also obtain the exact form of the f(R) model for some solutions. In the thermodynamic analysis, we calculate the thermodynamic quantities such as temperature and entropy of these solutions and compare them with the corresponding BTZ black holes. After that, we study the Ruppeiner geometry, such as the f(R)-gravity (extended black hole solution) of the BTZ black hole, and analyze the thermodynamic comparison of the Ruppeiner geometry with the van der Waals equation for its phase transition process.

gr-qc↗
arXiv2022

Thermodynamic geometric analysis of BTZ black hole under f(R) gravity

In this work, we obtained the black hole solutions in the expansion f(R)-gravitation (R is not regarded as a constant here), and studied their thermodynamics, especially the phase transition and criticality in anti-de Sitter Behavior (AdS) expands the phase space. We obtained accurate Banados, Teitelboim and Zanelli (BTZ) corresponding solutions in dilaton f(R)-gravity, which is the basis of our work. We also obtained the exact form of the f(R) model for some solutions. In thermodynamic analysis, we calculate thermodynamic quantities such as temperature and entropy of these solutions and compare them with the corresponding quantities of BTZ. After that, we study the Ruppeiner geometry, such as the f(R)-gravity of the BTZ black hole, and analyze its phase transition process Ruppeiner geometry.

gr-qc↗
arXiv2022

Analysis on superradiant instability of charged dilaton Black Hole

In this post, a new variable y($μ=yω$) is added to extend the results of the above post. We derive a very compact resonance formulation. When y is a certain limit, the effective potential of the equation exists at the pole, and the potential well appears outside the event horizon, when ${e}^{-4αΦ/(n-1)}\sqrtα Q \ll r_{+}\ll 1 / (\frac{4}{n-1}y) $, so charged dilator black hole is superradiatively unstable at this time.

gr-qc↗
arXiv2022

Analysis on superradiant stability of BTZ Black Hole

This paper adds a new variable y($μ^{\prime}=y(ω+m N^ϕ)$) to extend the results of the classic paper. We exploit the properties of curve integrals. When y is greater than a certain limit, the effective potential of the equation has no pole, then there is no potential well outside the event horizon, when $\sqrt{2(m^2)}/{ r^2_+}< ω< m\varOmega_H$,so the BTZ black hole was superradiantly stable at that time.

gr-qc↗
arXiv2022

Thermodynamic geometric analysis of conventional black holes under f(R) gravity

In this article, we consider a conventional black hole under f(R) gravity. Due to the small fluctuations around the equilibrium state, we have summarized the expression of the modified thermodynamic entropy of this black hole. At the same time, we also studied the geometric thermodynamics (GTD) of black holes, and studied the adaptability of the curvature scalar of the geometric thermodynamics method to the phase transition point of the black hole. In addition, we also studied the influence of the modified parameters on the thermodynamic behavior of black holes.

gr-qc↗
arXiv2019

Superradiant stability of the Kerr black holes

We study the superradiant stability of the system of a Kerr black hole and a massive scalar perturbation. It was proved previously that this system is superradiantly stable when $μ\geq \sqrt{2}mΩ_H$, where $μ$ is the proper mass of the scalar, $m$ is the azimuthal number of the scalar mode, and $Ω_H$ is the angular velocity of the Kerr black hole horizon. Our study is a complementary work of this result. We analytically prove that in the complementary parameter region $μ<\sqrt{2}mΩ_H$, when the parameters of scalar perturbation and Kerr black hole satisfy two simple inequalities, $ω<\fracμ{\sqrt{2}}$,~ $\frac{r_-}{r_+}<0.802$, the system is also superradiantly stable.

gr-qc↗