This book highlights selected topics of standard and modern theory of accretion onto black holes and magnetized neutron stars. The structure of stationary standard discs and non-stationary viscous processes in accretion discs are discussed to the highest degree of accuracy analytic theory can provide, including relativistic effects in flat and warped discs around black holes. A special chapter is dedicated to a new theory of subsonic settling accretion onto a rotating magnetized neutron star. The book also describes supercritical accretion in quasars and its manifestation in lensing events. Several chapters cover the underlying physics of viscosity in astrophysical discs with some important aspects of turbulent viscosity generation. The book is aimed at specialists as well as graduate students interested in the field of theoretical astrophysics.

The editor, Nikolai Shakura (b. 1945), is the head of the Relativistic Astrophysics Department of the Sternberg Astronomical Institute, where he has also been working all his life after graduating from the Lomonosov Moscow State University. In the early 70-s N.I.Shakura in collaboration with R.A.Sunyaev developed the fundamental theory of disc accretion onto relativistic compact stars. Even before the era of systematic X-ray observations of the sky, these authors predicted almost all observational manifestations of accreting neutron stars and black holes, which were later brilliantly confirmed by observations. Their work has been cited more than 8000 times. Overall, Nikolai Shakura is the author of more than 200 publications on accretion discs and considered a well acknowledged authority in the field.