Refined Gromov-Witten invariants

Seminar: 
Geometry, Symmetry and Physics
Event time: 
Thursday, October 23, 2025 - 4:30pm
Location: 
KT 801
Speaker: 
Yannik Schuler
Speaker affiliation: 
ETH Zurich
Event description: 

Abstract: Gromov–Witten invariants enumerate curves in a variety X via stable maps. In practise, degenerate contributions lead to substantial overcounting which makes these invariants far from being optimal. When X is a Calabi–Yau threefold, a set of more fundamental curve counting invariants is provided by Gopakumar–Vafa invariants. In this talk, I will propose a refined correspondence conjecture between Gromov–Witten and Gopakumar–Vafa invariants when X carries a non-trivial torus action. This refinement mathematically realises and generalises features which were expected from the so called refined topological string in physics literature. I will present evidence for the conjecture in case X is the local projective plane. This is based on joint work with Andrea Brini.