# Simple calculation of Compton scattering in string theory

1. Dec 4, 2015

### Strum

Hallo.
So the other day I reviewed a bit of quantum field theory and went through the Compton scattering calculation. To no ones surprise it was fairly simpel if you have a nice list of identities for rewriting the base results from the Feynman diagrams. See for exaxmple section 5.3 in http://arxiv.org/pdf/hep-th/0510040v4.pdf.

Is it possible to do something similar in string theory? That is, a really simple scattering amplitude calculated in a pedestrian way such that we can all understand it?

I searched a bit the other day but only found things which was way beyond what I could figure out in a short time. I've taken 1 course in bosonic string theory years ago but do not remember really trying to calculate anything explicitly( besides some 20 dimensions, unstable vacuum and a massless spin 2 excitation).

(BTW now I picked the graduate prefix but I really hope somebody can answer such that an undergrad can understand it. )

2. Dec 4, 2015

### MacRudi

Scattering calculation was the very first beginning of stringtheory and can be calculated by the veneziano amplitude. We have similar calculations as in conformal field theory.
https://en.wikipedia.org/wiki/Veneziano_amplitude

Because of the different stringtheories we have many different methods to calculate and can compare now a lot, what could be more realistic and what not.

By comparing all the different views on strings, we get more and more a hint what is more matching with the real world and what not.
Witten produced a lot of methods with others how to calculate scattering for different stringtheories.

But the veneziano amplitude is the mainframe of all calculations. The advanced and easier solution than hundreds of feynmann calculations, we are used to.

T Duality is something important in this idea too. But you should have learned in your bosonic course of string theory because it is the very beginning of string theory.

3. Dec 9, 2015

### Strum

Thanks for the answer. I do remember the T duality but I can not remember actually deriving the Veneziano amplitude. I will see if I can find my old lecture notes. From your answer I gather that there exists lots of different amplitudes. Any clear reference where some examples are calculated?