Ruben Minasian - CEA, Saclay: A general formalism for incorporating the string corrections in generalised geometry will be discussed. A particular example of this construction yields  the corrections linear in alpha' in heterotic strings. I’ll explain why a single order alpha’ term in the Bianchi Identity leads to corrections all order in alpha’s in the effective action, and will discuss terms up to order (alpha’)^4. I will also discuss what this construction cannot do and why. I’ll also discuss the fermionic condensates in heterotic strings. 3 Febbraio 2016.

DATA: 03-02-2016