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ON VARIETIES WITH TRIVIAL TANGENT BUNDLE IN CHARACTERISTIC $p>0$

Published online by Cambridge University Press:  26 June 2019

KIRTI JOSHI*
Affiliation:
Math. Department, University of Arizona, 617 N Santa Rita, Tucson 85721-0089, USA email [email protected]

Abstract

In this article, I give a crystalline characterization of abelian varieties amongst the class of smooth projective varieties with trivial tangent bundles in characteristic $p>0$. Using my characterization, I show that a smooth, projective, ordinary variety with trivial tangent bundle is an abelian variety if and only if its second crystalline cohomology is torsion-free. I also show that a conjecture of KeZheng Li about smooth projective varieties with trivial tangent bundles in characteristic $p>0$ is true for smooth projective surfaces. I give a new proof of a result by Li and prove a refinement of it. Based on my characterization of abelian varieties, I propose modifications of Li’s conjecture, which I expect to be true.

Type
Article
Copyright
© 2019 Foundation Nagoya Mathematical Journal

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