DYNAMICS OF ROTATING AND MAGNETIZED PARTICLES IN THE SPACE-TIME OF MODIFIED BLACK HOLES

Source abstract

The paper studies the dynamics of rotating and magnetized particles in the spacetime of modified black holes within the framework of a combined model of f(R)-gravity with k-essence as a source of dark energy. The motion of particles with spin and magnetic moment is described by the Matisson–Papapetrou–Dixon equations in the background of a generalized spherically symmetric metric containing additional modification parameters. Analytical expressions are obtained for the effective potential, the conditions for the existence and stability of circular orbits, as well as the radius of the inner stable circular orbit (ISCR). It is shown that an increase in the parameters of gravity modification and the parameter b of magnetic interaction leads to a noticeable increase in the radius of the ISCR and a change in the profile of the effective potential. Special attention is paid to the collision energy of two particles in the center of mass. It is established that in the modified metric, as well as in the classical Schwarzschild metric, the collision energy can be arbitrarily large near the horizon for certain kinematic configurations of the trajectories. The results have direct application to the modeling of accretion processes and high-energy phenomena around neutron stars, intermediate-mass and supermassive black holes, as well as to the testing of alternative theories of gravity using future gravitational-wave and astrometric observations. Keywords: modified black holes, effective potential, magnetized particles, orbital stability, Lagrangian.