Einstein's equations stem from General Relativity. In the context of
Riemannian manifolds, an independent mathematical theory has developed
around them. This is the first book which presents an overview of
several striking results ensuing from the examination of Einstein's
equations in the context of Riemannian manifolds. Parts of the text can
be used as an introduction to modern Riemannian geometry through topics
like homogeneous spaces, submersions, or Riemannian functionals.