Axel Kleinschmidt (AEI, Potsdam)

Title:
Closed string amplitudes at one loop and iterated integrals

Abstract:
Closed string amplitudes at genus can be expressed as integrals over the moduli space of punctured torus world-sheets. After performing the integral over the punctures, the integrand is SL(2,Z)-invariant and can be expanded in a series in the characteristic string length, corresponding to an effective low-energy approximation. The integrands turn out to be closely related to (single-valued) iterated integrals that have been studied recently in the mathematics literature. I will review this correspondence and the perspective string theory provides for it.

This talk will be in hybrid mode via zoom, please contact the seminar organizers to obtain the password.