Maths for Postgraduate String Theory: Analysis, Algebra, or Topology?

[mitcho]

I admit I don't know anything about string theory (nobody really does at an undergraduate level) but it sounds interesting and seems like something challenging. I am majoring in physics and maths but I am getting to the point in my undergraduate studies where I can begin to specialize more in my maths subjects. So my question is, what area of maths is the most beneficial to peruse this, analysis, algebra or something else? I hear topology is fairly important but that begs the same question, differential or algebraic?

On a related note, would I be better to have an official qualification in "mathematical physics" or "theoretical physic"?

Thanks

 

[mathman]

http://en.wikipedia.org/wiki/Calabi–Yau_space

Whatever field of mathematics which will include the above.