2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/166738Let $M$ be a compact orientable Seifered fibered 3-manifold without a boundary, and $α$ an $S^1$-invariant contact form on $M$. In a suitable adapted Riemannian metric to $α$, we provide a bound for the volume $\text{Vol}(M)$ and the curvature, which implies the universal tightness of the contact structure $ξ=\kerα$.26 pagesDifferential GeometrySymplectic Geometrytext