Hi guys... I'm just wondering, I'm taking this course about group theory in physics. The lecture sometimes really goes berserk.. by berserk i mean the professor starts talking about cohomology, complex manifolds... Sometimes he says somethings that I've never heard about (for instance, Young—Baxter equations, torsors and fibrations). The prerequisites for that class is merely a year of graduate quantum mechanics (no QFT). In that class I can really feel that sometimes... pretty much only one or two people are really following... So, my question is, what exactly is generally expected from a grad students (specially the ones going in theory)? should he/she know a good deal of differential geometry and topology? Where do they generally learn those things? just reading books? Or do they just dive right into crazy ideas and try to understanding the most complicated stuffs without any background (like in this class)?