Speaker
Oliver Schlotterer
Description
This talk is dedicated to one-loop amplitudes in open, closed and heterotic string theories
and aims to illustrate connections between their low-energy expansions. For open strings,
the coefficients in the one-loop alpha’-expansion are elliptic multiple zeta values which arise
from moduli-space integrals over punctured cylinders. Closed and heterotic strings in turn
introduce moduli-space integrals over punctured tori which evaluate to so-called modular
graph forms. These modular forms are observed to exhibit striking parallels to the elliptic
multiple zeta values in open-string expansions which should generalize the single-valued
projection of multiple zeta values known from genus zero.
