Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

Abstract

We present a review of the influence of cosmic repulsion and external magnetic fields on accretion disks rotating around rotating black holes and on jets associated with these rotating configurations. We consider both geometrically thin and thick disks. We show that the vacuum energy represented by the relic cosmological constant strongly limits extension of the accretion disks that is for supermassive black holes comparable to extension of largest galaxies, and supports collimation of jets at large distances from the black hole. We further demonstrate that an external magnetic field crucially influences the fate of ionized Keplerian disks causing creation of winds and jets, enabling simultaneously acceleration of ultra-high energy particles with energy up to 10 21 eV around supermassive black holes with M ∼ 10 10 M ⊙ surrounded by sufficiently strong magnetic field with B ∼ 10 4 G. We also show that the external magnetic fields enable existence of “levitating” off-equatorial clouds or tori, along with the standard equatorial toroidal structures, if these carry a non-vanishing, appropriately distributed electric charge.

Cosmic Ray Extremely Distributed Observatory

“…It is interesting to note that the black hole located at the centre of our Galaxy can accelerate particles up to the energies corresponding to the knee of the cosmic ray spectrum. On the right side of Figure 2 we demonstrate the results of numerical simulation of the magnetic Penrose process [for details, see 100,101,104]. Remarkably, the mechanism operates in viable physical conditions for typical SMBHs, without the need for a large acceleration zone or exotic assumptions for black holes.…”

Magnetized Particle Motion in γ-Spacetime in a Magnetic Field

“…We will consider the magnetized-magnetized, magnetized-neutral, and magnetized-charged particles collisions. The expression for the center-of-mass energy for two particles can be found as the sum of twomomenta [93,97,98]…”

“…On the other hand, the stability of the magnetized particle orbits depends on the parameters of the considered theory of gravity. However, the dynamics of the test of magnetized particles around compact objects leading to the degeneracy between the parameters of alternate theories of gravity and spin parameter of Kerr BH through the innermost stable circular orbit (ISCO) measurements are studied in [79][80][81]92,93].…”

Motion of spinning particles in non asymptotically flat spacetimes

“…All the theoretical models used to describe the observables obtained from accretion disks rely on the mathematical description of the motion of test particles and viscous plasma fluid in the surroundings of the black hole candidate. However, the motion of test particles may be influenced by a e-mail: bobir.toshmatov@nu.edu.kz (corresponding author) b e-mail: rahimov@astrin.uz c e-mail: ahmedov@astrin.uz d e-mail: daniele.malafarina@nu.edu.kz a large number of factors, including, for example, the geometry [5][6][7][8], the presence of external fields [9,10], the spin of the particles [11][12][13][14][15] and possible deviations from classical general relativity [16,17].…”