Rigid and Nonrigid Isotropic Nef Classes on K3 Surfaces
Let $X$ be a fixed complex K3 surface and let $0\ne\alpha\in\overline{Kah_X}$ be a $(1,1)$-class on the boundary of the K\"ahler cone with $\alpha^2=0$. We build a novel connection between two seemingly unrelated, intensively studied problems: the rigidity of a closed positive current in the class $\alpha$ and the coll...