Hypergeometric decomposition of symmetric K3 quartic pencils

Res Math Sci. 2020;7(2):7. doi: 10.1007/s40687-020-0203-3. Epub 2020 Mar 16.

Abstract

We study the hypergeometric functions associated to five one-parameter deformations of Delsarte K3 quartic hypersurfaces in projective space. We compute all of their Picard-Fuchs differential equations; we count points using Gauss sums and rewrite this in terms of finite-field hypergeometric sums; then we match up each differential equation to a factor of the zeta function, and we write this in terms of global L-functions. This computation gives a complete, explicit description of the motives for these pencils in terms of hypergeometric motives.