So I will soon be beginning an undergraduate degree in physics, going to a highly reputable university in Canada. My question is in regards to adding a second major in Math. I know that it's most likely to early for me to decide what area of physics I wan't to specialise in, but through lost of independent learning, and curiosity, I find my self interested in three main areas. High Energy Theory, Condensed Matter Theory, and Quantum Optics (particularly quantum information theory). Adding a second major means a slew of other courses, which I don't particularly mind, but I am concerned weather they will be of any use to me. I can definitely see courses like differential geometry, groups, rings, and complex analysis helping me out, but those are just a small number of courses that the second major would require. All of this got me thinking, so I checked the faculty website, and to my surprise, found that none of the professors in the High Energy theory area, had anything but the typical Bsc in physics. Most of the professors are older, so it could be that now one needs a more extensive background in order to enter those research areas, but I have been told that most if not all the mathematics required, is introduced in mathematical physics courses. What are your thoughts on this matter?