Symplectic $(-2)$-spheres and the symplectomorphism group of small rational 4-manifolds, II

Jun Li, Tian-Jun Li, Weiwei Wu

For $(\mathbb{C}{P}^2\#5\overline{\mathbb{C}{P}^2},\omega )$, let $N_{\omega }$ be the number of $(-2)$-symplectic spherical homology classes.We completely determine the Torelli symplectic ma…