Hawking radiation from the Schwarzschild black hole with a global monopole via gravitational anomaly

This paper derives the Hawking flux from the Schwarzschild black hole with a global monopole by using Robinson and Wilczek＇s method. Adopting a dimensional reduction technique, it can describe the effective quantum field in the （3 ＋ 1）-dimensional global monopole background by an infinite collection of the （1 ＋ 1）-dimensional massless fields if neglecting the ingoing modes near the horizon, where the gravitational anomaly can be cancelled by the （1 ＋ 1）- dimensional black body radiation at the Hawking temperature.

The global monopole spacetime and its topological charge

We show that the global monopole spacetime is one of the exact solutions of the Einstein equations by treating the matter field as a non-linear sigma model, without the weak field approximation applied in the original derivation by Barriola and Vilenkin. Furthermore, we find the physical origin of the topological charge in the global monopole spacetime. Finally, we generalize the proposal which generates spacetime from thermodynamical laws to the case of spacetime with global monopole charge.

Circular geodesics and accretion disk in the spacetime of a black hole including global monopole

We study circular time-like geodesics in the spacetime of a black hole including global monopole. We show that when the range of parameter changed the properties of the circular geodesics and the radiation of accretion disks are different. It follows that the properties of the accretion disk around black hole including global monopole can be different from that of a disk around Schwarzschild black hole.

Absorption cross section of black holes with global monopole

We study the absorption problem for a massless scalar field propagating in general static spherically-symmetric black holes with a global monopole. The absorption cross section expression is provided using a partial-wave method, which permits us to make an elegant and powerful resummation of the absorption cross section, and to extract the physical information encoded in the sum over the partial-wave contributions.

On the Thermodynamical Black Hole Stability in the Space-Time of a Global Monopole in f(R)-Gravity

In this work, we re-assess a class of black hole solutions in a global monopole spacetime in the framework of an f(R)-gravity model. Our main line of investigation consists in considering a region close enough to the black hole, but such that the weak field approximation is still valid. The stability of the black hole is studied in terms of its thermodynamical properties, with the radial coordinate written as a power-law function with the status of the main factor underneath the stability of the model. We obtain the explicit expressions for the thermodynamical quantities of the black hole as functions of the event horizon, by considering both the Hawking and the local temperatures. The phase transitions that may occur in this system, including the Hawking-Page phase transition, are inspected with particular attention. We work out and contemplate a solution of special interest in which one of the parameters is related to the cosmological constant. Our main result sets out to establish a comparison between both the Hawking and the local formalisms for the black hole in the framework of the f(R)-gravity in the particular space-time adopted here.

Instability of a black hole with f(R) global monopole under extended uncertainty principle

We consider the evolution of a black hole involving an f(R)global monopole based on the Extended Uncertainty Principle(EUP).The black hole evolutions refer to the instability due to the Parikh-Kraus-Wilczeck tunneling radiation or fragmentation.It is found that the EUP corrections make the entropy difference larger to encourage the black hole to radiate more significantly.We also show that the appearance of the EUP effects results in the black hole’s division.The influence from the global monopole and the revision of general relativity can also adjust the black hole evolution simultaneously but cannot change the final result that the black hole will not be stable because of the EUP’s effects.

Effects of a global monopole on the thermodynamic phase transition of a charged AdS black hole

We study the dynamical properties of the thermodynamic phase transition(PT)of a charged AdS black hole(BH)with a global monopole via the Gibbs free energy landscape and reveal the effects of the global monopole on the kinetics of thermodynamic PTs.First,we briefly review the thermodynamics of a charged AdS BH with a global monopole.Then,we introduce the Gibbs free energy landscape to investigate the thermodynamic stability of the BH states.Because of thermal fluctuations,the small black hole(SBH)state can transit to a large black hole(LBH)state,and vice versa.Further,we use the Fokker-Planck equation with the reflecting boundary condition to study the probability evolution of the BH state with and without a global monopole separately.It is found that for both the SBH and LBH states,the global monopole could slow down the evolution of the BH state.In addition,we obtain the relationship between the first passage time and the monopole parameterη.The result shows that as the monopole parameterηincreases,the mean first passage time becomes longer for both the SBH and LBH states.

Quantum Tunnelling and Hawking Radiation of Schwarzchild-Anti-de Sitter Black Hole with Topological Defect

We extend Parikh＇s recent work to Schwarzchild-anti-de Sitter black hole with topological defect whose Arnowitt-Deser-Misner （ADM） mass is no longer identical to its mass parameter. We view the Hawking radiation as a tunnelling process across the event horizon and the cosmological horizon. From the tunnelling probability, we find a leading correction to the semi-classical emission rate. The result employs an underlying unitary theory.

Topological defects on solutions of the non-relativistic equation for extended double ring-shaped potential

In this study, we focus into the non-relativistic wave equation described by the Schrodinger equation, specifically considering angular-dependent potentials within the context of a topological defect background generated by a cosmic string. Our primary goal is to explore quasi-exactly solvable problems by introducing an extended ring-shaped potential. We utilize the Bethe ansatz method to determine the angular solutions, while the radial solutions are obtained using special functions. Our findings demonstrate that the eigenvalue solutions of quantum particles are intricately influenced by the presence of the topological defect of the cosmic string,resulting in significant modifications compared to those in a flat space background. The existence of the topological defect induces alterations in the energy spectra, disrupting degeneracy.Afterwards, we extend our analysis to study the same problem in the presence of a ring-shaped potential against the background of another topological defect geometry known as a point-like global monopole. Following a similar procedure, we obtain the eigenvalue solutions and analyze the results. Remarkably, we observe that the presence of a global monopole leads to a decrease in the energy levels compared to the flat space results. In both cases, we conduct a thorough numerical analysis to validate our findings.