The null geodesics of the Reissner–Nordström black hole surrounded by quintessence

2015 ◽  
Vol 30 (10) ◽  
pp. 1550049 ◽  
Author(s):  
B. Malakolkalami ◽  
K. Ghaderi
Keyword(s):  
Black Hole ◽  
Effective Potential ◽  
Energy Levels ◽  
Schwarzschild Black Hole ◽  
Circular Orbits ◽  
Null Geodesics

In this paper, by using the effective potential for the photons, we analyze the null geodesics and all kinds of orbits corresponding to the energy levels for the Reissner–Nordström black hole surrounded by quintessence with [Formula: see text] and compare our results with those obtained for the Schwarzschild black hole surrounded by quintessence matter. We also investigate the circular orbits and calculate the angle of deflection of the photons.

Null and timelike geodesics of the Schwarzschild black hole with string cloud background

2017 ◽  
Vol 26 (05) ◽  
pp. 1741005 ◽  
Author(s):  
Mahwish Batool ◽  
Ibrar Hussain
Keyword(s):  
Black Hole ◽  
Effective Potential ◽  
Circular Motion ◽  
Schwarzschild Black Hole ◽  
Circular Orbits ◽  
Null Geodesics ◽  
Cloud Parameter

The trajectories of the time-like and null geodesics for radial and circular motion of the Schwarzschild black hole with string cloud background are investigated and compared with the Schwarzschild case without string clouds. It is found that in the presence of the string cloud parameter, the radius of the orbits is larger than the radius of the orbits in the case of the Schwarzschild black hole without string cloud parameter. Effective potential is calculated and it is observed that as the value of string cloud parameter increases the particle can more easily escape to infinity. Stability of the circular orbits is also discussed.

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.

Geodesic structure of magnetically charged regular black hole

2017 ◽  
Vol 14 (09) ◽  
pp. 1750120 ◽  
Author(s):  
Muhammad Azam ◽  
Ghulam Abbas ◽  
Syeda Sumera ◽  
Abdul Rauf Nizami
Keyword(s):  
Black Hole ◽  
Effective Potential ◽  
Proper Time ◽  
Massive Particle ◽  
Circular Motion ◽  
Geodesic Path ◽  
Timelike Geodesic ◽  
Null Geodesics ◽  
Regular Black Hole ◽  
Geodesic Structure

The purpose of this paper is to study the geodesic structure of magnetically charged regular black hole (MCRBH). The behavior of timelike and null geodesics of MCRBH is investigated. The graphs have been plotted to show the relation between distance versus time and proper time for photon-like and massive particle. For radial and circular motion, the effective potential has been plotted with different parameters of BH. We conclude that massive particles move around the BH in timelike geodesic path.

scholarly journals Geodesic motion near self-gravitating scalar field configurations

2019 ◽  
Vol 27 (3) ◽  
pp. 231-241
Author(s):  
Ivan M. Potashov ◽  
Julia V. Tchemarina ◽  
Alexander N. Tsirulev
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Circular Orbit ◽  
Naked Singularity ◽  
Schwarzschild Black Hole ◽  
Null Geodesics ◽  
Naked Singularities ◽  
Test Particles ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

We study the geodesics motion of neutral test particles in the static spherically symmetric spacetimes of black holes and naked singularities supported by a selfgravitating real scalar field. The scalar field is supposed to model dark matter surrounding some strongly gravitating object such as the centre of our Galaxy. The behaviour of timelike and null geodesics very close to the centre of such a configuration crucially depends on the type of spacetime. It turns out that a scalar field black hole, analogously to a Schwarzschild black hole, has the innermost stable circular orbit and the (unstable) photon sphere, but their radii are always less than the corresponding ones for the Schwarzschild black hole of the same mass; moreover, these radii can be arbitrarily small. In contrast, a scalar field naked singularity has neither the innermost stable circular orbit nor the photon sphere. Instead, such a configuration has a spherical shell of test particles surrounding its origin and remaining in quasistatic equilibrium all the time. We also show that the characteristic properties of null geodesics near the centres of a scalar field naked singularity and a scalar field black hole of the same mass are qualitatively different.

scholarly journals Photon Spheres, ISCOs, and OSCOs: Astrophysical Observables for Regular Black Holes with Asymptotically Minkowski Cores

Universe ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 2
Author(s):  
Thomas Berry ◽  
Alex Simpson ◽  
Matt Visser
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Circular Orbit ◽  
Schwarzschild Black Hole ◽  
Circular Orbits ◽  
Regular Black Hole ◽  
Astrophysical Interest ◽  
Regular Black Holes ◽  
Recent Advances ◽  
Classical Black Holes

Classical black holes contain a singularity at their core. This has prompted various researchers to propose a multitude of modified spacetimes that mimic the physically observable characteristics of classical black holes as best as possible, but that crucially do not contain singularities at their cores. Due to recent advances in near-horizon astronomy, the ability to observationally distinguish between a classical black hole and a potential black hole mimicker is becoming increasingly feasible. Herein, we calculate some physically observable quantities for a recently proposed regular black hole with an asymptotically Minkowski core—the radius of the photon sphere and the extremal stable timelike circular orbit (ESCO). The manner in which the photon sphere and ESCO relate to the presence (or absence) of horizons is much more complex than for the Schwarzschild black hole. We find situations in which photon spheres can approach arbitrarily close to (near extremal) horizons, situations in which some photon spheres become stable, and situations in which the locations of both photon spheres and ESCOs become multi-valued, with both ISCOs (innermost stable circular orbits) and OSCOs (outermost stable circular orbits). This provides an extremely rich phenomenology of potential astrophysical interest.

scholarly journals Self-force of a scalar field for circular orbits about a Schwarzschild black hole

2003 ◽  
Vol 67 (10) ◽  
Author(s):  
Steven Detweiler ◽  
Eirini Messaritaki ◽  
Bernard F. Whiting
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Schwarzschild Black Hole ◽  
Circular Orbits ◽  
Self Force

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.

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