2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/99129We show that Gopakumar-Vafa invariants can be expressed in terms of the cohomology ring of moduli space of D-branes without reference to the sl_2 \times sl_2 action. We also give a simple construction of this action.9 pages, some additions and clarifications, minor changesHigh Energy Physics - TheoryAlgebraic Geometrytext