Title: Enumerative invariants of noncommutative Calabi-Yau threefolds
Abstract: In this talk, I consider a class of nodal Calabi-Yau threefolds X which do not admit Kahler small resolutions. Nevertheless, topological string amplitudes can be associated to analytic small resolutions of X with topologically nontrivial B-fields. These amplitudes can be computed by B-model techniques, leading to integer-valued enumerative invariants. These X also admit noncommutative resolutions. A theory of Gopakumar-Vafa invariants of a larger class of noncommutative Calabi-Yau threefolds is introduced, which are conjectured to agree with the enumerative invariants computed by the B-model techniques. This talk is based on arXiv:2212.08655, arXiv:2307.00047, and work in progress.