Quantum gravity

A summary of the search for a quantum theory of gravity. Changes over the last few years have been due to the success of renormalized Yang-Mills gauge theory which has stimulated interest in quantum field theory. There has also been the development of supersymmetry and supergravity theories and the discovery by Hawking of the thermal radiation produced when a quantum field propagates in a black hole background. This leads to a synthesis of thermodynamics, quantum theory and general relativity. Traditionally the gravitational field has been quantized by 'canonical' and 'covariant' methods with a concentration on the covariant approach. (UK)