A characterization of ordinary abelian varieties by the Frobenius push-forward of the structure sheaf

Abstract

For an ordinary abelian variety X, \(F^e_*\mathcal {O}_X\) is decomposed into line bundles for every positive integer e. Conversely, if a smooth projective variety X satisfies this property and the Kodaira dimension of X is non-negative, then X is an ordinary abelian variety.