Instanton representation of Plebanski gravity. Gravitational instantons from the classical formalism

Abstract

We present a reformulation of general relativity as a `generalized' Yang--Mills theory of gravity, using a SO(3,C) gauge connection and the self-dual Weyl tensor as dynamical variables. This formulation uses Plebanski's theory as the starting point, and obtains a new action called the instanton representation (IRPG). This paper has yielded a collection of various new results, which show that the IRPG is indeed a fundamentally new approach to GR which should not be confused with existing approaches. Additionally, the IRPG appears to provide a realization of the relation amongst general relativity, Yang--Mills theory and instantons.