English

On the Frobenius stable part of Witt vector cohomology

Algebraic Geometry 2010-07-29 v1

Abstract

For a proper (not necessarily smooth) variety over a finite field with q elements, Berthelot-Bloch-Esnault proved a trace formula which computes the number of rational points modulo q in terms of the Witt vector cohomology. We show the analogous formula for Witt vector cohomology of finite length. In addition, we prove a vanishing result for the compactly supported \'etale cohomology of a constant p-torsion sheaf on an affine Cohen-Macaulay variety in positive characteristic p.

Keywords

Cite

@article{arxiv.1007.5000,
  title  = {On the Frobenius stable part of Witt vector cohomology},
  author = {Andre Chatzistamatiou},
  journal= {arXiv preprint arXiv:1007.5000},
  year   = {2010}
}