Hi everyone, I've been accepted to a graduate school that is good in gravitation, which is what I want to do. Here is the thing: lately I've been wondering if I should've become a mathematician instead of a physicist. I was a dual math/physics major for my undergrad. work, and loved the math side - mostly geometry, algebra, topology, etc. I did research in general relativity as an undergrad. and loved it, but my research was on the mathy side of things (finding isometry groups, classifying things, etc.). Now the grad program I'm heading to is good in gravity, but I think leans more toward the astrophysics approach - specifically a lot of data analysis, modeling binary coalescence, etc. The problem is I don't know what that really entails. Will there be any math in this stuff? I love my upper division physics courses, esp. quantum, but I can't imagine my life doing some kind of research without utilizing any pretty math (manifolds, groups, etc.). Have I made a huge mistake in choosing physics over math? What kind of math is typically employed for the average theoretical astrophysicist? How "mathy" can one make this stuff?