/ Marcy Robertson: Automorphisms of seamed surfaces, modular operads and Galois actions

Marcy Robertson: Automorphisms of seamed surfaces, modular operads and Galois actions

March 8, 2022
4:30 pm - 5:30 pm

Abstract: The idea behind Grothendieck-Teichmüller theory is to study the absolute Galois group via its actions on (the collection of all) moduli spaces of genus g curves. In practice, this is often done by studying an intermediate object: The Grothendieck-Teichmüler group, GT. In this talk, I’ll describe an algebraic gadget built from simple decomposition data of Riemann surfaces. This gadget, called an infinity modular operad, provides a model for the collection of all moduli spaces of genus g curves with n boundaries, which we justify by showing that the automorphisms of this algebraic object is isomorphic to a subgroup of Grothendieck-Teichmüller group.