We present detailed calculations of the structure and the spectrum of massive, geometrically
thin,'bare'accretion discs. The calculations are for an α-disc, with various assumptions about …

During recent years my research on the primitive solar nebular has followed two main
themes:(1) Very early in the development of the nebula conditions probably favored the …

We study the vertical structure of a radiation-pressure-dominated disc with a hot corona. We
include all the relevant processes like bound-free opacity and convection. We show that the …

We present angular momentum transport (torque) measurements in two recent experimental
studies of the turbulent flow between independently rotating cylinders. In addition to these …

We consider the twisted accretion disc around a Kerr black hole and derive the stationary
twist equation in the leading order on small parameters of relative thickness δ, viscosity α …

The theoretical framework for modeling the primordial solar nebula is presented in which
convection is assumed to be the sole source of turbulence that causes the nebula to evolve …

One of the major challenges in modern astrophysics is the unexplained turbulence of gas-
dynamic (nonmagnetic) accretion disks. Since they are stable, such disks should not …

We derive the system of equations describing the time dependent twisted accretion disc
around a Kerr black hole (twist equations). The post-Newtonian corrections to the equations …

We review some aspects of a major unsolved problem in understanding astrophysical (in
particular, accretion) disks: whether the disk interiors can be effectively viscous in spite of the …

A model for stationary, fully developed turbulence is presented. The physical model used to
describe the nonlinear interactions provides an equation for the turbulent spectral energy …