Undergraduate on Physics or Maths for Theor.Phys aspirants?

[Calabi_Yau]

I have done some research about the maths and physics behind theoretical physics (i.e. string theory, which was mentioned in this forum earlier today) and it seems to me that in the cutting edge fields of study, like M-Theory, pure mathematics is as important as background knowledge in physics (am I wrong?). So my question is, is it more advisable to get to theoretical physics by a career path in mathematics or physics?

Is it important to choose physics first, but not that relevant whether we choose maths or physics in grad school?

I would like to hear your insights about this. Thanks in advance.

 

[SophusLies]

I did a double major in physics and math and I'm currently doing a PhD in physics (theoretical side of AMO). A large chunk of pure math classes didn't help directly to my physics ability because those classes view math for math's sake not applications. I went the algebra/analysis route for the math classes I picked and I took several at the graduate level during my undergrad years. The "applications" were only applications to different problems in pure math which was fine by me because I enjoy pure math but others thought it was dumb and served no purpose for their work.

I've found that the secret is to find a professor that has dabbled in physics or is an actual physicist teaching a pure math class. This is pretty rare to find someone like this but my school had a handful and these few classes were breathtaking to say the least and really made me want to get into mathematical physics for my PhD.

The biggest problem with mathematical physics is finding an adviser (and a job.. because that's a very specialized area with not a lot of opportunity) that can satisfy both subjects without getting buried into one or the other. I searched for an adviser, through emails mostly, and the ones I wanted to study with weren't taking on new students. So, I applied to schools that had other math-physics type professors and it turned out that their students weren't getting jobs afterwards so I said forget it and turned to something that can reasonably satisfy my needs and that has a lot of connections with industry (and funding).

All in all, choose what you like the most now and decide later on which to pursue more.

 

[Mépris]

I think John Baez, at UC Riverside, does that kind of mathematical physics? I wouldn't know for sure; I'm only going by what I remember reading on his website.

 

[ahsanxr]

I was asking myself a similar question and still don't have the exact details of what formal degrees I will be getting. But what I am making sure though is that I take advanced classes in both math and physics. So if you're interested in the "cutting-edge" fields of theoretical physics these days regardless of what you major in, you need to try your best to take as much advanced math and physics classes as possible. Here's what you should take beyond the intro-level:

Physics: A year of undergraduate Quantum Mechanics followed by a year of more advanced/graduate-level QM and then a year of Quantum Field Theory (you should start undergrad QM your second year if you want to do this), a year of E&M, at least a semester of advanced Classical Mechanics, Statistical Mechanics and General Relativity each.

Mathematics: ODEs/PDEs of course, Complex Analysis, Advanced Linear Algebra, Abstract Algebra, Real Analysis, General Topology, Algebraic and Differential Topology. Classes on Differential Geometry and Lie Algebras/Representation Theory would also be nice.

So with this rather ambitious list one will no doubt be able to get a Mathematics degree, however for a Physics major most places would require at least 2-3 semesters of lab. So with these if you have time to fit labs in as well, get a Physics degree too. I personally haven't had time to fit in those labs yet and I only have 3 more semesters left and a whole bunch of other classes I would rather take, so I may not get a BS in Physics. Regardless class-wise this should be excellent preparation for graduate school in theoretical physics.

As far as what to apply for in grad school, I'll just say that I've seen quite some people with physics backgrounds who work in mathematics departments but none the other way around.