RANK ONE CONNECTIONS ON ABELIAN VARIETIES

Abstract

Let A be a complex abelian variety. The moduli space [Formula: see text] of rank one algebraic connections on A is a principal bundle over the dual abelian variety A∨ = Pic 0(A) for the group [Formula: see text]. Take any line bundle L on A∨; let [Formula: see text] be the algebraic principal [Formula: see text]-bundle over A∨ given by the sheaf of connections on L. The line bundle L produces a homomorphism [Formula: see text]. We prove that [Formula: see text] is isomorphic to the principal [Formula: see text]-bundle obtained by extending the structure group of the principal [Formula: see text]-bundle [Formula: see text] using this homomorphism given by L. We compute the ring of algebraic functions on [Formula: see text]. As an application of the above result, we show that [Formula: see text] does not admit any nonconstant algebraic function, despite the fact that it is biholomorphic to (ℂ*)2 dim A implying that it has many nonconstant holomorphic functions.