Description:

This talk aims to give a gentle introduction to the effective-field-theory viewpoint on tree-level scattering amplitudes in superstring theories. Their low-energy expansion around the point-particle limit signals infinite towers of higher-derivative interactions of non-abelian gauge fields and gravitational states. The coefficients at arbitrary derivative orders are explicitly  known combinations of multiple zeta values — certain generalizations of the Riemann zeta function at integer values. The appearance of multiple zeta values in open- and closed-string tree amplitudes follows elegant patterns of common interest in string theory, particle physics and number theory: The higher-derivative interactions of open strings are intertwined through the so-called ``Galois coaction'' of (motivic) multiple zeta values and determine those of closed strings through their ``single-valued map’’.

Oliver Schlotterer, Associate Professor, Uppsala University

Host: John Joseph Carrasco