Title: The Large Scale Structure of α′ Effects in String Theory

Abstract:

The main open technical problem to extract EFTs for string compactifications is deriving corrections to the tree level supergravity actions. In this talk, I summarise three attempts to systematically analyse α′-effects in string theory and its compactifications by utilising the impressive machinery of string dualities. First, I show how to derive kinematical structures in the 10-dimensional type IIB action from 1-loop amplitudes in the 11d superparticle calculus. I argue that this approach can compete with the results obtained from string scattering amplitudes. Secondly, applying an approach based on a dimensional analysis, I claim that conventional Kaluza-Klein reductions of M-theory on elliptically fibered Calabi-Yau fourfolds can only give rise to (α′)even-corrections in the 4d F-theory effective action. In a final attempt, I use constraints from supersymmetry in 4 dimensions to determine SL(2,Z)-completed index structures of 8-derivative terms in the bulk action of type IIB.