Uniqueness of symplectic canonical class, surface cone and symplectic cone of 4-manifolds with b^+=1

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60523Let M be a closed oriented smooth 4-manifold admitting symplectic structures. If M is minimal and has b^+=1, we prove that there is a unique symplectic canonical class up to sign, and any real second cohomology class of positive square is represented by symplectic forms. Similar results hold when M is not minimal.36 pages, typos corrected, references added, improved expositionsSymplectic GeometryAlgebraic GeometryGeometric TopologyUniqueness of symplectic canonical class, surface cone and symplectic cone of 4-manifolds with b^+=1text