Seminarium Teorii Względności i Grawitacji

I will discuss recent results in modeling of self-gravitating stationarydisks (tori) around black holes. These models include both magnetized andunmagnetized disks with polytropic or realistic equations of state. From thetechnical point of view, modeling of black hole-disk systems amounts to solving a set of Einstein equations coupled with the equations of general-relativistic (magneto)hydrodynamics. There is an interesting structure of the space of solutions, revealing classic nonlinear phenomena---nonuniqueness of solutions and bifurcations. In some cases, these phenomena can be explained as related to the changes in the spacetime geometry. The talk will be based on series of works, including: PRD 99, 104063 (2019), PRD 101, 044036 (2020), PRD 104, 024005 (2021), and PRD 104, 044058 (2021).