This review covers the main aspects of black hole accretion disk theory. We begin with the
view that one of the main goals of the theory is to better understand the nature of black holes …

Black hole accretion flows can be divided into two broad classes: cold and hot. Whereas
cold accretion flows consist of cool optically thick gas and are found at relatively high mass …

The disc instability model which is supposed to describe outbursts of dwarf nova and low-
mass X-ray binary transient systems is presented and reviewed in detail. Various …

We model the broad-band (optical/UV and X-ray) continuum spectrum of the 'changing-
look'active galactic nucleus (AGN) Mrk 1018, as it fades from Seyfert 1 to 1.9 in∼ 8 years …

As the luminosity of an accreting black hole drops to a few percent of Eddington, the
spectrum switches from the familiar soft state to a hard state that is well-described by a …

We study the prospect of explaining the outbursts of Soft X-ray Transients (SXTs) by the
thermal-viscous instability in a thin disc. This instability is linked to hydrogen ionization and …

We present a model for the anomalous X-ray pulsars (AXPs) in which the emission is
powered by accretion from a fossil disk, established from matter falling back onto the neutron …

Recently, several ways of verifying the existence of black-hole horizons have been
proposed. We show here that most of these suggestions are irrelevant to the problem of the …

This paper reviews the current status of black hole (BH) astrophysics, focusing on topics of
interest to a physics audience. Astronomers have discovered dozens of compact objects …

The similarity of rotation periods of the anomalous X-ray pulsars (AXPs), the soft gamma-ray
repeaters (SGRs), and the dim isolated thermal neutron stars (DTNs) suggests a common …