Timelike geodesics of a modified gravity black hole immersed in an axially symmetric magnetic field

Abstract

Abstract:We investigate the dynamics of a neutral and a charged particle around a black hole in modified gravity immersed in magnetic field. Our focus is on the scalar-tensor-vector theory as modified gravity. We are interested to explore the conditions on the energy of the particle under which it can escape to infinity after collision with another neutral particle in the vicinity of the black hole. We calculate escape velocity of particle orbiting in the innermost stable circular orbit (ISCO) after the collision. We study the effects of modified gravity on the dynamics of particles. Further we discuss how the presence of magnetic field in the vicinity of black hole, effects the motion of the orbiting particle. We show that the stability of ISCO increases due to presence of magnetic field. It is observed that a particle can go arbitrary close to the black hole due to presence of magnetic field. Furthermore ISCO for black hole is more stable as compared with Schwarzschild black hole. We also discuss the Lyapunov exponent and the effective force acting on the particle in the presence of magnetic field. * Electronic address: s

Modified gravity black hole lensing observables in weak and strong field of gravity

“…From the Eqs. (19)(20)(21)(22), it is seen that the MOG parameter α has invaded all quantities including ε and ϑ E so that they deviate from the fixed values of SGR (α = 0), hence the deviation is already liable to be observed. Note that for our chosen interval, −1 < α < 3, ε continues to remain small justifying the PPN expansion.…”

“…MOG has already been receiving attention among the astrophysics community since it successfully explains not only the local weak field tests, but also the rotation curves of nearby galaxies [10][11][12][13][14], the dynamics of globular clusters in the galactic halo [10,11,15,16], and cosmological observations [17] without requiring the dark matter paradigm of GR [12][13][14][18][19][20][21][22]. Properties of accretion disks around supermassive BHs in MOG and a detectable influence of the parameter α on the accretion charateristics of supermassive BH (SMBH) has been noted [13].…”

“…Properties of accretion disks around supermassive BHs in MOG and a detectable influence of the parameter α on the accretion charateristics of supermassive BH (SMBH) has been noted [13]. Stability of circular orbits around a SMOG in the ambience of a weak magnetic field has been studied [22]. The latest success of MOG [23] is that it can reproduce with reasonable accuracy the observed velocity dispersion in the ultra-diffuse galaxy N GC1052 − DF 2 that shows it to be devoid of dark matter [24].…”

Vacuum and nonvacuum black holes in a uniform magnetic field

“…Other applications will follow [29]. The generalization along with the corrections made to Wald's formulas are crucial for a consistent analysis of (un)charged-particle dynamics around black holes [4][5][6][35][36][37][38], to mention but a few. From this point of view, some particle-dynamics analyses made in the literature have relied on Wald's formulas in cases where they do not apply.…”

Exact cosmological black hole solutions in scalar tensor vector gravity

“…2 Different aspects of the STVG black hole solutions have been extensively studied in the literature: accretion disks around Schwarzschild and Kerr STVG black holes [22], shadows cast by near-extremal Kerr STVG black holes [23], black hole superradiance in STVG [24], quasinormal modes of Schwarzschild STVG black holes [25], the process of acceleration and collimation of relativistic jets in Kerr STVG black holes [26], dynamics of neutral and charged particles around a Schwarzschild STVG black hole immersed in a weak magnetic field [27], among others. 3 As suggested by Moffat and Rahvar [9] and Moffat and Toth [36], we dismiss the scalar field ω, and we treat it as a constant, ω = 1.…”