Euclidean quantum gravity

Euclidean quantum gravity is a version of quantum gravity. 

Euclidean quantum gravity uses the Wick rotation to describe gravity according to quantum mechanics. The Wick rotation is named after the Italian physicist Gian Carlo Wick, as a method of solving a problem in Minkowski space from a solution to a similar problem in Euclidean space. 

The Wick rotation trades one dimension of space for one dimension of time. 

The Wick rotation substitutes a problem in Minkowski space into a related problem in Euclidean space. This transformation substitutes an imaginary number variable for a real number variable. 

Euclidean quantum gravity refers to a Wick rotated version of quantum gravity formulated as a quantum field theory. The manifolds used are 4-dimensional Riemannian manifolds, which are compact, connected and boundaryless or without singularities.