Gromov-Witten invariants of the Hilbert scheme of points of a K3 surface (and more) -- Georg Oberdieck, November 20, 2015
A theorem of Maulik-Pandharipande-Thomas asserts that the Gromov-Witten theory of K3 surfaces is governed by quasi-modular forms. In this talk I will discuss a generalization of their result to the Hilbert scheme of 2 points of a K3 surface, the analog of a K3 surface in dimension 4, namely: The genus 0 Gromov Witten theory of Hilb2(K3) (in primitive classes) is governed by quasi-Jacobi forms. If time permits, I will explain how this leads to new curve-counting formulas on the K3 surface itself.