Ion tori around f(R)-Kerr black holes

Abstract

Black holes offer one of the best scenarios to explore deviations from General Relativity in the strong field regime. Alternative theories of gravity, in particular $f(R)$ theories, that have been extensively analyzed in cosmological contexts, could be tested through astrophysical models of accretion process around black holes. In this work we model a low accretion process onto an $f(R)$-Kerr black hole by an optically thin ion torus. We first compute the torus geometry by analyzing the particle motion in $f(R)$-Kerr spacetime. Assuming a two temperature plasma, we characterize the thermodynamics quantities of the torus and compare our results with those corresponding to General Relativity. We analyze the impact of the variation of the Ricci scalar on the synchrotron emission associated with a supermassive black hole.