Group Actions, Cyclic Coverings and Families of K3-Surfaces

Abstract

AbstractIn this paper we describe six pencils of K3-surfaces which have large Picard number (ρ = 19, 20) and each contains precisely five special fibers: four have A-D-E singularities and one is non-reduced. In particular, we characterize these surfaces as cyclic coverings of some K3-surfaces described in a recent paper by Barth and the author. In many cases, using 3-divisible sets, resp., 2-divisible sets, of rational curves and lattice theory, we describe explicitly the Picard lattices.