Generic vanishing index and the birationality of the bicanonical map of irregular varieties

Abstract

We prove that any smooth complex projective variety with generic vanishingindex bigger or equal than 2 has birational bicanonical map. Therefore, if $X$ is a smoothcomplex projective variety $\varphi$ with maximal Albanese dimension and non-birational bicanonical map, then the Albanese image of $X$ is fibred by subvarieties of codimension at most 1 of an abelian subvariety of Alb $X$.