Perspective on geometric analysis S. T. Yau's 2006 survey paper. On page 2, we find his Basic Philosophy: Functions, tensors and subvarieties governed by natural differential equations provide deep insight into geometric structures. Information about these objects will give a way to construct a geometric structure. They also provide important information for physics, algebraic geometry and topology. Conversely it is vital to learn ideas from these fields.
Geometric Analysis Introductory Articles
in general relativity Mihalis Dafermos's article in the Proceedings of ICM 2014.