scholarly journals GEODESIC STRUCTURE OF THE SCHWARZSCHILD BLACK HOLE IN RAINBOW GRAVITY

2009 ◽  
Vol 24 (18) ◽  
pp. 1443-1451 ◽  
Author(s):  
CARLOS LEIVA ◽  
JOEL SAAVEDRA ◽  
JOSÉ VILLANUEVA
Keyword(s):  
Black Hole ◽  
Test Particle ◽  
Radial Motion ◽  
Schwarzschild Black Hole ◽  
Geodesic Structure

In this paper we study the geodesic structure of the Schwarzschild black hole in rainbow gravity analyzing the behavior of null and time-like geodesic. We find that the structure of the geodesics essentially does not change when the semiclassical effects are included. However, we can distinguish different scenarios if we take into account the effects of rainbow gravity. Depending on the type of rainbow functions under consideration, inertial and external observers see very different situations in radial and non-radial motion of a test particle.

Polar trajectories around a black hole in a magnetic field

1989 ◽  
Vol 67 (10) ◽  
pp. 971-973
Author(s):  
K. D. Krori ◽  
J. C. Sarmah
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Angular Momentum ◽  
Test Particle ◽  
Field Parameter ◽  
Schwarzschild Black Hole ◽  
Magnetic Field Parameter ◽  
Neutral Test ◽  
Test Particles ◽  
The Magnetic Field

In this paper, we present a study of the stable polar trajectories ([Formula: see text] = constant plane) of neutral test particles around a Schwarzschild black hole embedded in a magnetic field. We also show how the nature of these trajectories changes with the variation in the angular momentum of the test particle and the magnetic field parameter.

scholarly journals Local free-fall temperature of modified Schwarzschild black hole in rainbow spacetime

2016 ◽  
Vol 31 (17) ◽  
pp. 1650106 ◽  
Author(s):  
Yong-Wan Kim ◽  
Young-Jai Park
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Test Particle ◽  
Free Fall ◽  
Local Temperature ◽  
Schwarzschild Black Hole ◽  
Energy Formula ◽  
Fall Temperature ◽  
Flat Embedding

We obtain a (5+1)-dimensional global flat embedding of modified Schwarzschild black hole in rainbow gravity. We show that local free-fall temperature in rainbow gravity, which depends on different energy [Formula: see text] of a test particle, is finite at the event horizon for a freely falling observer, while local temperature is divergent at the event horizon for a fiducial observer. Moreover, these temperatures in rainbow gravity satisfy similar relations to those of the Schwarzschild black hole except the overall factor [Formula: see text], which plays a key role of rainbow functions in this embedding approach.

scholarly journals GEODESIC STRUCTURE OF TEST PARTICLE IN BARDEEN SPACETIME

2012 ◽  
Vol 21 (09) ◽  
pp. 1250077 ◽  
Author(s):  
SHENG ZHOU ◽  
JUHUA CHEN ◽  
YONGJIU WANG
Keyword(s):  
Black Hole ◽  
Energy Level ◽  
Test Particle ◽  
Effective Potential ◽  
Null Geodesic ◽  
Low Velocity ◽  
Effective Potentials ◽  
Black Hole Spacetime ◽  
Geodesic Structure ◽  
Bound Orbits

The Bardeen model describes a regular spacetime, i.e. a singularity-free black hole spacetime. In this paper, by analyzing the behavior of the effective potential for the particles and photons, we investigate the timelike and null geodesic structures in the Bardeen spacetime. At the same time, all kinds of orbits, which are allowed according to the energy level corresponding to the effective potentials, are numerically simulated in detail. We find many-world bound orbits, two-world escape orbits and escape orbits in this spacetime. We also find that bound orbits precession directions are opposite and their precession velocities are different, the inner bound orbits shift along counter-clockwise with high velocity while the exterior bound orbits shift along clockwise with low velocity.

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.

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