Symmetry of hypergeometric functions over finite fields and geometric interpretation

Abstract: We begin by defining general hypergeometric functions over finite fields and proving a finite field analogue of a classical symmetry in their complex counterparts. Next, we up grade this symmetry to explicit isomorphisms between algebraic varieties defined by products of Fermat hypersurfaces and Artin-Schreier curves. The numbers of rational points on these varieties are hypergeometric functions over finite fields.