A $p$-adic de Rham complex
Abstract
This is the second in a sequence of three articles exploring the relationship between commutative algebras and -algebras in characteristic and mixed characteristic. Given a topological space we construct, in a manner analogous to Sullivan's -functor, a strictly commutative algebra over which we call the de Rham forms on . We show this complex computes the singular cohomology ring of . We prove that it is quasi-isomorphic as an -algebra to the Berthelot-Ogus-Deligne \emph{d\'ecalage} of the singular cochains complex with respect to the -adic filtration. We show that one can extract concrete invariants from our model, including Massey products which live in the torsion part of the cohomology. We show that if is formal then, except at possibly finitely many primes, the -adic de Rham forms on are also formal. We conclude by showing that the -adic de Rham forms provide, in a certain sense, the "best functorial strictly commutative approximation" to the singular cochains complex.
Cite
@article{arxiv.2501.10164,
title = {A $p$-adic de Rham complex},
author = {Oisín Flynn-Connolly},
journal= {arXiv preprint arXiv:2501.10164},
year = {2025}
}
Comments
22 pages. Comments are welcome