I'm a second year undergrad, currently majoring both in mathematics and physics. However I've decided that the time has come where I should stop taking both classes evenly and start devoting more of my time to one field. However I'm unsure which field that should be if I'm interested primarily in theoretical/mathematical physics. To give you guys a better idea here's what I was thinking about taking in fall 2012. If I go math-heavy: Real analysis Topology Graduate Algebra 1 Graduate Quantum Mechanics 1 If I go physics-heavy: Either Topology or Analysis Elementary Lab 1 Graduate Quantum Mechanics 1 E&M II Statistical Mechanics. Which side should I focus on in your opinions? If I do decide to go math-heavy I probably won't be doing the 3 required lab semesters of the physics BS, and hence I won't have a formal degree in physics although I would have taken classes up til QFT by the time I graduate. How would physics schools view that if I decide to apply to them for theory? Similarly if I decide decide to focus on physics I won't be able to take a lot of math grad classes. How then would that be viewed by the math/mathematical physics graduate schools?