2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69173We compute the local Gromov-Witten invariants of the "closed vertex", that is, a configuration of three rational curves meeting in a single triple point in a Calabi-Yau threefold. The method is to express the local invariants of the vertex in terms of ordinary Gromov-Witten invariants of a certain blowup of CP^3 and then to compute those invariants via the geometry of the Cremona transformation.11 pagesAlgebraic GeometryHigh Energy Physics - Theory14J32,14N35text