Hyperplane sections of abelian surfaces

Elisabetta Colombo, Paola Frediani, Giuseppe Pareschi

Published 2009-03-16, updated 2010-01-28Version 2

By a theorem of Wahl, the canonically embedded curves which are hyperplane section of K3 surfaces are distinguished by the non-surjectivity of their Wahl map. In this paper we address the problem of distinguishing hyperplane sections of abelian surfaces. The somewhat surprising result is that the Wahl map of such curves is (tendentially) surjective, but their second Wahl map has corank at least 2 (in fact a more precise result is proved).