Hey u guys. Say I'm an undergraduate wanting to be a physicist. Not just any physicist, but a theoretical physicist. Say that I'm already planning on taking all of the "Mathematical methods for Physics" courses offered at my university, but now I want more of some math action. Which subjects of upper div math classes do you think are the most important for physicists to learn? Also, as a second question: Would double-majoring in mathematics (or maybe just minoring in it) greatly help?