EVENT DETAILS AND ABSTRACT

Title: Dehn twists and free subgroups of the symplectic mapping class group
Speaker: Ailsa Keating
Speaker Info: MIT
Brief Description:
Special Note:
Abstract:

Given two Lagrangian spheres in an exact symplectic manifold, we present conditions under which the Dehn twists about them generate a free non-abelian subgroup of the symplectic mapping class group. This extends a result of Ishida for Riemann surfaces. The proof generalises the categorical version of Seidel’s long exact sequence to arbitrary powers of a fixed Dehn twist. Time allowing, we construct families of examples containing such spheres.