2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107454A version of the Donaldson-Thomas invariants of a Calabi-Yau threefold is proposed as a conjectural mathematical definition of the Gopakumar-Vafa invariants. These invariants have a local version, which is verified to satisfy the required properties for contractible curves. This provides a new viewpoint on the computation of the local Gromov-Witten invariants of contractible curves by Bryan, Leung, and the author.Algebraic GeometryHigh Energy Physics - Theorytext