Hello all, I am currently an undergraduate in physics and have a significant amount of room in my schedule for classes. This is because I took mostly maths and general classes my freshman year, when deciding my major, and now will have to stay an extra half or full year to complete the core physics classes. My question is what classes outside of physics(if any) will advance my chances of getting accepted into graduate school. I am not interested in double majoring and a mathematics minor is basically contained within the physics major. I have a choice of classes from any other field and maths which aren't included in the physics degree, and I was just wondering what would be most helpful? Maybe just any maths which aren't required that you graduate students find yourself using on a regular basis that I could get a jump start on, or anything else that would make me a more well rounded physicist. Maths which are required: Obviously Calc I,II, and III, Differential equations, Partial Differential equations and linear algebra.(I noticed that absolutely no statistics is required, perhaps I am expected to pick that up in quantum?) If it helps my area of interest for graduate school is theory in either astrophysics or particle physics.