Modern General Relativity - Hardcoverby August Hall (Editor) The general theory of relativity, also called the Einstein's theory of gravity and the general relativity theory, is the geometric theory of gravitation. It provides the description of gravity as a geometric property of space and time. There are several astrophysical applications of the general theory of relativity including gravitational lensing, cosmology, gravitational wave astronomy, and black holes. The theory of general