Here are some notes which might be useful. Any typos/corrections is greatly appreciated. Please send them to ranveersfl@gmail.com.

1. Introduction to String Theory
2. Ideal Class Group
3. Projective Representations of the Poincare Group
4. Spinor-Helicity Formalism
5. Ramanujan’s Tau Function and Mock Modular Forms
6. The AdS-CFT Correspondence
7. Donaldson-Witten Theory