English

Revisiting the de Rham-Witt complex

Algebraic Geometry 2020-02-20 v3

Abstract

The goal of this paper is to offer a new construction of the de Rham-Witt complex of smooth varieties over perfect fields of characteristic p>0p>0. We introduce a category of cochain complexes equipped with an endomorphism FF of underlying graded abelian groups satisfying dF=pFddF = pFd, whose homological algebra we study in detail. To any such object satisfying an abstract analog of the Cartier isomorphism, an elementary homological process associates a generalization of the de Rham-Witt construction. Abstractly, the homological algebra can be viewed as a calculation of the fixed points of the Berthelot-Ogus operator LηpL \eta_p on the pp-complete derived category. We give various applications of this approach, including a simplification of the crystalline comparison for the AΩA \Omega-cohomology theory introduced in [BMS18].

Keywords

Cite

@article{arxiv.1805.05501,
  title  = {Revisiting the de Rham-Witt complex},
  author = {Bhargav Bhatt and Jacob Lurie and Akhil Mathew},
  journal= {arXiv preprint arXiv:1805.05501},
  year   = {2020}
}

Comments

158 pages. Final version. Contains a new section on the comparison with crystalline cohomology

R2 v1 2026-06-23T01:55:01.526Z