Lagrangian spheres, symplectic surfaces and the symplectic mapping class group

Tian-Jun Li, Weiwei Wu

Given a Lagrangian sphere in a symplectic 4-manifold $(M,\omega )$ with $b^{+}=1$, we find embedded symplectic surfaces intersecting it minimally. When the Kodaira dimension $\kappa$ of $(M, ω…