A bit of background: I am currently a fifth year Mathematics and Chemistry double major with a minor in Physics. My interests (as well as my degree plan) has greatly evolved over the course of my undergraduate career, and I am in my final year with a great interest in furthering my knowledge of quantum mechanics and other subjects (like statistical mechanics) that will help me better understand the fundamental constituents of the Universe. I have also always been far more adept at theory than at experiment, and I do not 100% know what I want to do after I graduate, but I am currently in the process of applying for graduate schools to see where that will take me. My top choice for the graduate program I am hoping to get into is the Applied and Industrial Mathematics (AIM) program at the University of Michigan, which allows students to use applied mathematics to investigate a co-discipline, such as physics. I figure this would be a great route for me since it would allow me to use my undergraduate major towards a theoretical investigation into a subject in physics, such as quantum mechanics. However, I also want to apply to a Master's program as a back-up plan in case my application is rejected, and most applied mathematics graduate programs are not as closely tied to the other subject as the AIM program. So, my question is whether I would be better off applying for a Master's in Applied Math or a Master's in Physics? With my background, how likely is it that I could get accepted into a Physics Master's program since I did not major in physics? Also, if I went the route of the Applied Math Master's program, could I take physics graduate courses while working towards the Master's in Applied Math or are students usually not allowed to take graduate courses outside of their discipline? Thank you in advance for any help or suggestions on what to do. It is greatly appreciated!