I'm a rising math major with a developing interest in General Relativity. I think the idea of studying Relativity from a mathematicians perspective sounds very appealing for graduate work. Besides differential geometry and partial differential equations, what are the most relevant pure math courses to this area of research? Also, how about applied courses as well as non-linear dynamics type stuff? Do this subjects find relevance in GR? One of the reasons I ask is because I'm trying to decide if I should continue on to graduate-level algebra courses, as well as topology, or if I should just stick with analysis and geometry. Thanks for any advice you may give.