2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221995In this article we present infinitely many 3-manifolds admitting infinitely many universally tight contact structures each with trivial Ozsvath-Szabo contact invariants. By known properties of these invariants the contact structures constructed here are non weakly symplectically fillable.This is the version published by Geometry & Topology on 2 April 2006Geometric TopologySymplectic Geometry57R17, 57R57text