Hypergeometric functions and a family of algebraic curves

Abstract

Let $\lambda \in \mathbb{Q}\setminus \{0,1\}$ and $l\ge 2$, and denote by $C_{l,\lambda }$ the nonsingular projective algebraic curve over $\mathbb{Q}$ with affine equation given by $$y^l=x(x-1)(x-\lambda ).$$ In this paper we define $\Omega (C_{l,\lambda })$ analogous to the real periods of elliptic curves and find a relation with ordinary hypergeometric series. We also give a relation between the number of points on $C_{l,\lambda }$ over a finite field and Gaussian hypergeometric series. Finally we give an alternate proof of a result of \cite{rouse}.

10 pages