2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/62131We investigate the bounded cohomology of Lefschetz fibrations. If a Lefschetz fibration has regular fiber of genus at least 2 and it has at least two distinct vanishing cycles, we show that its Euler class is not bounded. As a consequence, we exclude the existence of negatively curved metrics on Lefschetz fibrations with more than one singular fiber.8 pages, submitted to NYJMGeometric TopologyAlgebraic TopologySymplectic Geometry57N65text