Extensions of line bundles and Brill--Noether loci of rank-two vector bundles on a general curve

Abstract

In this paper we study Brill-Noether loci for rank-two vector bundles and describe the general member of some components as suitable extensions of line bundles.Comment: 31 pages; revised version after referees' comments; to appear in Revue Roumaine de Math\'ematiques Pures et Appliqu\'ee