String topology and the geometric decomposition of three manifolds

Moira Chas (SUNY Stony Brook)

Abstract: In the late nineties, in joint work with Dennis Sullivan, we generalized Goldman's Lie algebra structure to a graded Lie algebra on families of loops (defining the equivariant homology of the free loop space of a manifold of any dimension). This graded Lie algebra, together with other operations in spaces of loops is known now as String Topology. We will describe the String topology bracket on the free loop space of three manifolds and how this structure can be used to recognize hyperbolic and Seifert vertices and the gluing graph in the geometrization of three manifolds. Time permits, we will discuss other applications of String Topology to three manifolds (These are different works of Abbaspour, Basu, Gadgil, McGibbon, D. Sullivan, M. Sullivan and myself).