Solutions of the elliptic qKZB equations and Bethe ansatz I

We give an integral representation for solutions of the elliptic quantum Knizhnik-Zamolodchikov-Bernard difference equations, in the case of sl(2). The result is based on a geometric construction of highest weight representations of the elliptic quantum group associated to sl(2). We also obtain Bethe ansatz eigenfunctions for the corresponding integrable systems of difference operators, and prove their completeness in some cases.