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Exotic Torsion, Frobenius Splitting and the Slope Spectral Sequence

Published online by Cambridge University Press:  20 November 2018

Kirti Joshi*
Affiliation:
Mathematics Department, University of Arizona, 617 N. Santa Rita, Tucson, AZ 85721-0089, U.S.A. e-mail: [email protected]
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Abstract

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In this paper we show that any Frobenius split, smooth, projective threefold over a perfect field of characteristic $p\,>\,0$ is Hodge–Witt. This is proved by generalizing to the case of threefolds a well-known criterion due to $\text{N}$. Nygaard for surfaces to be Hodge-Witt. We also show that the second crystalline cohomology of any smooth, projective Frobenius split variety does not have any exotic torsion. In the last two sections we include some applications.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2007

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