On transfer of mass and angular momentum from accretion disk onto black hole

We study the properties of accretion tori orbiting Kerr black hole. Our approach to this problem comes from the solving of general relativistic magnetohydrodynamic equations, which follow from conservation of the energy-momentum tensor, the particle number and from Maxwell's equations. We solve these equations by numerical methods. We are interested in tori with constant density of angular momentum and those with radially increasing angular momentum density. We study accretion rates in these tori when the mass of black hole is increased suddenly and so the equilibrium in the torus is perturbed. We also study the influence of the presence of toroidal magnetic field on accretion rates