Hello! I'm a European physics student with an interest in what I believe to be mathematical physics. I'm torn between going for a master in physics or one in mathematics as more and more it seems to me that the research areas I'm interest are often conducted in the mathematics department. While I'm about to complete a bachelor in physics I've also taken several extra courses in mathematics making me meet the requirements of a master in mathematics. To describe what I hope to be doing is to work on physics or physics related problems from a theorem proof perspective or at least involving interesting calculations in a mathematical framework. So is there any way to tell which department would be a better fit? Generally I enjoyed the core physics courses, CM,EM, QM, Stat.Mech. etc. while more specialised topics didn't seem to be my thing. I also had a lot of fun in pretty much all the math courses I've taken, Abstract algebra, Real analysis, Fourier analysis, Differential Geometry, Topology and the proof/theorem style really seemed to be my thing. Going for a physics master it seems to mainly contain courses that I'm very interested in and most likely would take either way. On the other hand the mathematics master allows me to take some of these physics courses while replacing the few more specialised/experimental courses with mathematics courses such a functional analysis, algebraic geometry etc. which all look very interesting. The main difference I think will be if it matters if I do my thesis in the physics or math department and which gives me a suitable background to be able to apply for phd positions in mathematical physics.