Description
Chairman: Agnieszka Janiuk
In this talk we will introduce a new formalism to calculate nonlinear oscillations of fluids based on non-self-adjoint operators. The formalism is very intuitive, based on Eulerian description of perturbations and can be seen as an alternative to the standard Lagrangian approach used in the theory of nonlinear stellar pulsations. First we will review basic properties of nonlinear oscillations...
For a wide class of spherically symmetric naked singularities there is a sphere within which gravity is effectively repulsive. In such space-times accreting matter cannot reach the singularity and will instead form a levitating atmosphere, which is kept suspended by gravity alone. The density of the atmosphere has a maximum at a definite radius. In its properties the atmosphere is analogous to...
I will present results inferred from numerical study of geometrically thin accretion disk. The radiation-pressure dominated thin accretion disks undergo thermal instability which has been infamous for decades. We confirmed this instability in a 3D global radiative GRMHD simulation. In order to further understand thermal instability, we simulated GRHD models with \alpha-viscosity and concluded...