So, as I kind of expected, after not studying much for the physics subject GRE I did very badly, ~20th percentile. I'm still applying to some schools, but with limited hope. I now have to decide - I can do a year-long MS in physics or math, then retake the subject GRE. I'm thinking about changing to math (not sure yet), because I'm slightly better at it, but have some questions: 1) will it hurt to have bombed the physics GRE if I do okay on the math GRE in a year? or, since it was physics, will it not really matter at all? 2) how different is mathematical physics for a mathematician than it is for a physicist? I was planning to to gravitational physics, but it's specifically the math in GR that excites and drives me, so I am pretty sure I'd be happy doing math. But I'm not sure how different the emphasis is, and also, all my research has been more from the physics side, so I'm not sure what research in math is like or if I'd be good at it. I think I can handle math classes; I have taken some graduate math classes as an undergrad and immensely enjoyed them. And also, I don't need any responses telling me to give up because I'm not smart enough. There is a tendency for people to do that on these forums. I am quite smart enough, just didn't spend the time necessary to prepare. (And I hadn't taken several core classes when I took the physics GRE, so I think that's part of the score as well).