Roadmap for learning String Theory?

[patrik1982]

One of my goals in life is to get a reasonable understanding of string theory. This is done as a hobby of mine so I will not have a professor to ask.

My question is: which route would you recommend for learning this?

My thoughts:

I understand many people think highly of "A First Course in String Theory" by Zwiebach so this is probably the path I will take - unless you guys would recommend another path.
But I cannot find any info on the prerequisites for this book.

I have an understanding of quantum mechanics at the level of Shankar (up to, and including, the chapter on addition of angular momentum).
Is this enough or do I need to learn the rest of that book?

Do I need QFT? If so - what is a good book for me?

Do I need GR? I do have the books by Carroll and Schutz but I haven't read them yet. Do I have to? (I do have a firm understanding of SR)

 

[Physics Monkey]

Hi patrik1982,

Welcome to PF!

I would say it depends on your detailed goals. Zwiebach is, in my opininon, a very fun book, but it spends a lot of time on classical physics. If for you a "reasonable understanding" includes the ability to do some calculations in the quantum theory, then zwiebach may move a bit slowly. However, I would heartily recommend the earlier chapters regardless of your goals, and I think its a good book to look back to later on for a simpler conceptual take.

In my experience, QFT and GR are what most string theorists do on a daily basis. But again, it depends on what you really want to achieve. To have some flavor of holographic duality, for example, you will need some of both QFT and GR. I really don't know how much of a real picture one can have, beyond some inspired metaphors, for holographic duality without knowing a bit of QFT and GR. On the other hand, one can actually understand much of the basic physics without more technical things like supersymmetry.

A reasonable conceptual picture could be built from studying Zee's QFT in a nutshell and Zwiebach's string theory. Perhaps the most important thing is that Zee teaches you to think about QFT in the correct "wilsonian" way. These two might be a bit of stretch from where you are now, but I'm sure you would enjoy it.

With some feedback from you about your expectations, I'm sure we could narrow things down even more.