2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107485We show that fiberwise stable vector bundles are preserved by relative Fourier-Mukai transforms between elliptic threefolds with relative Picard number one. Using these bundles we define new invariants of elliptic fibrations, and we relate the invariants of a space with those of a relative moduli space of stable sheaves on it. As a byproduct, we calculate the intersection form of a certain new example of an elliptic Calabi-Yau threefold.4 pages, non-standard format usedAlgebraic Geometry14D20, 14D22text