The Coble-Mukai lattice from $\mathbb Q$-Gorenstein deformations

Abstract

We show some geometric properties of Enriques surfaces via $\mathbb Q$-Gorenstein smoothings of Coble surfaces. In particular, we explicitly identify the Enriques lattice of the general fiber with the Coble-Mukai lattice. At the end, we discuss applications to Gorenstein $\mathbb Q$-Homology projective planes with trivial canonical class.