General Properties of Black Holes

Abstract

So far we have restricted the description of the properties of black holes to an analysis of the Schwarzschild and Kerr metrics and their perturbations. Both Schwarzschild and Kerr spacetimes are stationary and possess certain symmetries. A study of geodesies (corresponding to the motion of test particles and light rays) and wave fields in these metrics enabled us to describe a number of interesting and important features of physical effects in the field of such black holes. It is natural to ask: Are there black holes that differ from those already described? What are their properties? In order to answer these questions, the definition must first of all be extended to the general case of non-stationary spacetime. This generalization is obvious. It is reasonable to define the black hole in general as the region of spacetime from which no information-carrying signals are allowed to escape to a distant observer.