How much mathematics must a theoretical physicist know?/Alternatives to string theory

Philosopher_k

Ok, i have come to a realisation that my interests revolve not around pure mathematics (as i once thought) and more around theoretical physics, some people would claim that they merge into one at times, and that leads on to my question. If i wanted to be a theoretical physicist (rather than an experimental physicist), but am not keen on string theory, are there any other fields of theoretical physicis which i could focus on in grad school? Why am i not keen on string theory? well the answer is twofold, one i doubt i could match the contributions of the likes of witten and greene and secondly, i am slightly dubious of the credibility and goals of string theory.

My second Question is, how much mathematics must i complete to become a theoretical physicist? (i use this parameter loosly as i am aware you never stop learning mathematics) say i want to learn quantum field theory or Paticle theory in grad school, will mathematics up to complex analysis/fluid dynamics/advanced PDEs (the applied side) suffice, or will i need to learn topology, representation theory, functional analyisis (the pure side) as well?

Klockan3

Most physicists never even learns string theory so this is a really strange comment.

xGAME-OVERx

There's all sorts of work going on in all kinds of directions. It's not all strings! Condensed Matter Theory is probably the most obvious one. Google some theoretical physics departments and see what kind of research they're doing - that'll give you a pretty decent idea.

twofish-quant

The undergraduate physics program is intentionally designed to give you the minimal set of mathematics so that you can do physics research in graduate school.

Yes. But a lot of this will be on demand learning, which is to say that you learn the math at the same time you learn the physics. Also, you'll invariably find in learning any area of physics that you will need to learn new math, and what math you learn is field dependent. For example, if you do any sort of physical cosmology you'll find that you'll need need a lot of statistics that you didn't cover as an undergraduate. If you do computational work, there is a ton of math that you need to learn on the side to do that work.