scholarly journals Wave dynamics of phantom scalar perturbation in the background of Schwarzschild black hole

2009 ◽  
Vol 670 (4-5) ◽  
pp. 276-280 ◽  
Author(s):  
Songbai Chen ◽  
Jiliang Jing ◽  
Qiyuan Pan
Keyword(s):  
Black Hole ◽  
Scalar Perturbation ◽  
Schwarzschild Black Hole ◽  
Wave Dynamics ◽  
Phantom Scalar

scholarly journals AdS Black Hole with Phantom Scalar Field

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Limei Zhang ◽  
Xiaoxiong Zeng ◽  
Zhonghua Li
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Entanglement Entropy ◽  
Scalar Fields ◽  
Schwarzschild Black Hole ◽  
Ricci Flat ◽  
Large Black Hole ◽  
Phantom Scalar ◽  
Strip Geometry ◽  
Phantom Scalar Field

We present an AdS black hole solution with Ricci flat horizon in Einstein-phantom scalar theory. The phantom scalar fields just depend on the transverse coordinates x and y, which are parameterized by the parameter α. We study the thermodynamics of the AdS phantom black hole. Although its horizon is a Ricci flat Euclidean space, we find that the thermodynamical properties of the black hole solution are qualitatively the same as those of AdS Schwarzschild black hole. Namely, there exists a minimal temperature and the large black hole is thermodynamically stable, while the smaller one is unstable, so there is a so-called Hawking-Page phase transition between the large black hole and the thermal gas solution in the AdS space-time in Poincare coordinates. We also calculate the entanglement entropy for a strip geometry dual to the AdS phantom black holes and find that the behavior of the entanglement entropy is qualitatively the same as that of the black hole thermodynamical entropy.

Quasinormal modes of scalar perturbation around a quantum-corrected Schwarzschild black hole

2014 ◽  
Vol 350 (2) ◽  
pp. 721-726 ◽  
Author(s):  
Mahamat Saleh ◽  
Bouetou Bouetou Thomas ◽  
Timoleon Crepin Kofane
Keyword(s):  
Black Hole ◽  
Quasinormal Modes ◽  
Scalar Perturbation ◽  
Schwarzschild Black Hole

scholarly journals ASYMPTOTIC QUASINORMAL MODES OF A NONCOMMUTATIVE GEOMETRY INSPIRED SCHWARZSCHILD BLACK HOLE

2007 ◽  
Vol 22 (11) ◽  
pp. 2047-2056 ◽  
Author(s):  
PULAK RANJAN GIRI
Keyword(s):  
Black Hole ◽  
Noncommutative Geometry ◽  
Quasinormal Modes ◽  
Space Time ◽  
Hawking Temperature ◽  
Scalar Perturbation ◽  
Schwarzschild Black Hole ◽  
The Real ◽  
Quasinormal Frequency

We study the asymptotic quasinormal modes for the scalar perturbation of the noncommutative geometry inspired Schwarzschild black hole in 3+1 dimensions. We have considered M ≥ M0, which effectively correspond to a single horizon Schwarzschild black hole with correction due to noncommutativity. We have shown that for this situation the real part of the asymptotic quasinormal frequency is proportional to ln (3). The effect of noncommutativity of space–time on quasinormal frequency arises through the constant of proportionality, which is Hawking temperature TH(θ). We also consider the two-horizons case and show that in this case also the real part of the asymptotic quasinormal frequency is proportional to ln (3).

The Schwarzschild black hole

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Equilibrium Configuration ◽  
Original Form ◽  
Schwarzschild Black Hole ◽  
Schwarzschild Metric ◽  
Schwarzschild Geometry

This chapter discusses the Schwarzschild black hole. It demonstrates how, by a judicious change of coordinates, it is possible to eliminate the singularity of the Schwarzschild metric and reveal a spacetime that is much larger, like that of a black hole. At the end of its thermonuclear evolution, a star collapses and, if it is sufficiently massive, does not become stabilized in a new equilibrium configuration. The Schwarzschild geometry must therefore represent the gravitational field of such an object up to r = 0. This being said, the Schwarzschild metric in its original form is singular, not only at r = 0 where the curvature diverges, but also at r = 2m, a surface which is crossed by geodesics.

scholarly journals Black hole S-matrix for a scalar field

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Panos Betzios ◽  
Nava Gaddam ◽  
Olga Papadoulaki
Keyword(s):  
Black Hole ◽  
Normal Modes ◽  
Massless Scalar ◽  
Scattering Process ◽  
Schwarzschild Black Hole ◽  
Asymptotically Flat ◽  
Scalar Particles ◽  
Black Hole Background ◽  
S Matrix ◽  
Do So

Abstract We describe a unitary scattering process, as observed from spatial infinity, of massless scalar particles on an asymptotically flat Schwarzschild black hole background. In order to do so, we split the problem in two different regimes governing the dynamics of the scattering process. The first describes the evolution of the modes in the region away from the horizon and can be analysed in terms of the effective Regge-Wheeler potential. In the near horizon region, where the Regge-Wheeler potential becomes insignificant, the WKB geometric optics approximation of Hawking’s is replaced by the near-horizon gravitational scattering matrix that captures non-perturbative soft graviton exchanges near the horizon. We perform an appropriate matching for the scattering solutions of these two dynamical problems and compute the resulting Bogoliubov relations, that combines both dynamics. This allows us to formulate an S-matrix for the scattering process that is manifestly unitary. We discuss the analogue of the (quasi)-normal modes in this setup and the emergence of gravitational echoes that follow an original burst of radiation as the excited black hole relaxes to equilibrium.

scholarly journals Null Geodesics and Strong Field Gravitational Lensing in a String Cloud Background

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. Sharif ◽  
Sehrish Iftikhar
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Galactic Center ◽  
Deflection Angle ◽  
Orbital Motion ◽  
Strong Field ◽  
Schwarzschild Black Hole ◽  
Field Limit ◽  
Null Geodesics ◽  
Supermassive Black Hole

This paper is devoted to studying two interesting issues of a black hole with string cloud background. Firstly, we investigate null geodesics and find unstable orbital motion of particles. Secondly, we calculate deflection angle in strong field limit. We then find positions, magnifications, and observables of relativistic images for supermassive black hole at the galactic center. We conclude that string parameter highly affects the lensing process and results turn out to be quite different from the Schwarzschild black hole.

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