scholarly journals Trajectory around a spherically symmetric non-rotating black hole

2011 ◽  
Vol 89 (6) ◽  
pp. 689-695 ◽  
Author(s):  
Sumanta Chakraborty ◽  
Subenoy Chakraborty
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Gravitational Potential ◽  
Test Particle ◽  
Effective Potential ◽  
Particle Motion ◽  
Spherically Symmetric ◽  
Rotating Black Hole

The trajectory of a test particle or a photon around a general spherical black hole is studied, and bending of the light trajectory is investigated. A pseudo-Newtonian gravitational potential describing the gravitational field of the black hole is determined and is compared with the related effective potential for test particle motion. As an example, results are presented for a Reissner–Nordström black hole.

scholarly journals Timelike geodesics around a charged spherically symmetric dilaton black hole

2015 ◽  
pp. 41-48 ◽  
Author(s):  
C. Blaga
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Test Particle ◽  
Effective Potential ◽  
Equations Of Motion ◽  
Equation Of Motion ◽  
Qualitative Approach ◽  
Extremal Black Hole ◽  
Spherically Symmetric ◽  
Dilaton Black Hole

In this paper we study the timelike geodesics around a spherically symmetric charged dilaton black hole. The trajectories around the black hole are classified using the effective potential of a free test particle. This qualitative approach enables us to determine the type of orbit described by test particle without solving the equations of motion, if the parameters of the black hole and the particle are known. The connections between these parameters and the type of orbit described by the particle are obtained. To visualize the orbits we solve numerically the equation of motion for different values of parameters envolved in our analysis. The effective potential of a free test particle looks different for a non-extremal and an extremal black hole, therefore we have examined separately these two types of black holes.

scholarly journals Particle Motion around Charged Black Holes in Generalized Dilaton-Axion Gravity

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Susmita Sarkar ◽  
Farook Rahaman ◽  
Irina Radinschi ◽  
Theophanes Grammenos ◽  
Joydeep Chakraborty
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Effective Potential ◽  
Particle Motion ◽  
Spherically Symmetric ◽  
Asymptotically Flat ◽  
Four Dimensions ◽  
Charged Black Holes ◽  
Test Particles ◽  
Massive Particles

The behaviour of massive and massless test particles around asymptotically flat and spherically symmetric, charged black holes in the context of generalized dilaton-axion gravity in four dimensions is studied. All the possible motions are investigated by calculating and plotting the corresponding effective potential for the massless and massive particles as well. Further, the motion of massive (charged or uncharged) test particles in the gravitational field of charged black holes in generalized dilaton-axion gravity for the cases of static and nonstatic equilibrium is investigated by applying the Hamilton-Jacobi approach.

scholarly journals PSEUDO-NEWTONIAN GRAVITATIONAL POTENTIAL FOR SCHWARZSCHILD–DE SITTER SPACE–TIMES

2008 ◽  
Vol 17 (11) ◽  
pp. 2089-2105 ◽  
Author(s):  
ZDENĚK STUCHLÍK ◽  
JIŘÍ KOVÁŘ
Keyword(s):  
Black Holes ◽  
Gravitational Field ◽  
Accretion Disks ◽  
Gravitational Potential ◽  
Test Particle ◽  
De Sitter Space ◽  
Spherically Symmetric ◽  
De Sitter ◽  
General Relativistic ◽  
The Universe

Pseudo-Newtonian gravitational potential describing the gravitational field of static and spherically symmetric black holes in the universe with a repulsive cosmological constant is introduced. In order to demonstrate the accuracy of the pseudo-Newtonian approach, the related effective potential for test particle motion is constructed and compared with its general-relativistic counterpart given by the Schwarzschild–de Sitter geometry. The results indicate that such an approach could be useful in applications of developed Newtonian theories of accretion disks in astrophysically interesting situations in large galactic structures for the Schwarzschild–de Sitter space–times with the cosmological parameter y = Λ M2/3 ≤ 10-6.

scholarly journals Second post-Minkowskian metric for a moving Kerr black hole

2014 ◽  
Vol 23 (09) ◽  
pp. 1450079 ◽  
Author(s):  
G. He ◽  
C. Jiang ◽  
W. Lin
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Gravitational Potential ◽  
Test Particle ◽  
Constant Velocity ◽  
Arbitrary Constant ◽  
Equations Of Motion ◽  
Kerr Black Hole ◽  
Time Dependent

In this paper, the harmonic metric for a moving Kerr black hole is presented in the second post-Minkowskian approximation. It is further demonstrated that the obtained metric is consistent with the Liénard–Wiechert gravitational potential for a moving and spinning source with an arbitrary constant velocity. Based on the metric, we also give the post-Newtonian equations of motion for photon and massive test particle in the time-dependent gravitational field.

Accretion onto a Black Hole

2014 ◽  
Author(s):  
Charles D. Bailyn
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Gas Flow ◽  
Gravitational Potential Energy ◽  
Spherically Symmetric ◽  
Potential Well ◽  
Accretion Flows ◽  
Flow Geometry

This chapter explores the ways that accretion onto a black hole produces energy and radiation. As material falls into a gravitational potential well, energy is transformed from gravitational potential energy into other forms of energy, so that total energy is conserved. Observing such accretion energy is one of the primary ways that astrophysicists pinpoint the locations of potential black holes. The spectrum and intensity of this radiation is governed by the geometry of the gas flow, the mass infall rate, and the mass of the accretor. The simplest flow geometry is that of a stationary object accreting mass equally from all directions. Such spherically symmetric accretion is referred to as Bondi-Hoyle accretion. However, accretion flows onto black holes are not thought to be spherically symmetric—the infall is much more frequently in the form of a flattened disk.

scholarly journals MAGNETIZED PARTICLE MOTION AROUND BLACK HOLE IN BRANEWORLD

2011 ◽  
Vol 26 (06) ◽  
pp. 399-408 ◽  
Author(s):  
O. G. RAHIMOV
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Effective Potential ◽  
Particle Motion ◽  
Uniform Magnetic Field ◽  
Radial Motion ◽  
Circular Orbits ◽  
Spinning Particle ◽  
Jacobi Formalism

We investigate the motion of a magnetized particle orbiting around a black hole in braneworld immersed in asymptotically uniform magnetic field. The influence of brane parameter on effective potential of the radial motion of magnetized spinning particle around the braneworld black hole using Hamilton–Jacobi formalism is studied. It is found that circular orbits for photons and slowly moving particles may become stable near r = 3M. It was argued that the radii of the innermost stable circular orbits are sensitive on the change of brane parameter. Similar discussion without Weil parameter has been considered by de Felice et al. in Refs. 1 and 2.

scholarly journals Test-particle dynamics in general spherically symmetric black hole spacetimes

2018 ◽  
Vol 97 (10) ◽  
Author(s):  
Mariafelicia De Laurentis ◽  
Ziri Younsi ◽  
Oliver Porth ◽  
Yosuke Mizuno ◽  
Luciano Rezzolla
Keyword(s):  
Black Hole ◽  
Test Particle ◽  
Particle Dynamics ◽  
Spherically Symmetric ◽  
Black Hole Spacetimes ◽  
Symmetric Black Hole

scholarly journals Greybody factor for a rotating black hole with quintessential energy

2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
M Sharif ◽  
Qanitah Ama-Tul-Mughani
Keyword(s):  
Black Hole ◽  
Effective Potential ◽  
State Parameter ◽  
Scalar Fields ◽  
Accelerated Expansion ◽  
Massless Scalar ◽  
Emission Rates ◽  
Rotating Black Hole ◽  
Klein Gordon ◽  
Tortoise Coordinate

Abstract This paper is devoted to deriving an analytic expression of the greybody factor for a rotating black hole surrounded by quintessence. Primarily, we transform the radial part of the Klein–Gordon equation into the standard Schrödinger equation through the tortoise coordinate to analyze the profile of the effective potential. Asymptotic solutions are obtained in two distinct regions, namely, the black hole and cosmological horizons determined by the quintessential field. We then extrapolate these solutions and match them smoothly in an intermediate region to extend the viability over the whole radial regime. To elaborate the significance of the analytical solution, we evaluate the emission rates and absorption cross-section for the massless scalar fields. It is found that the accelerated expansion of the universe corresponding to smaller values of the state parameter minimizes the effective potential and consequently increases the emission process of the scalar field particles.

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