Plectic structures in p-adic de Rham cohomology
Abstract
Given a Hilbert modular form for a totally real field , and a prime split completely in , the -eigenspace in -adic de Rham cohomology of the Hilbert modular variety has a family of partial filtrations and partial Frobenius maps, indexed by the primes of above . The general plectic conjectures of Nekovar and Scholl suggest a "plectic comparison isomorphism" comparing these structures to etale cohomology. We prove this conjecture in the case under some mild assumptions; and for general we prove a weaker statement which is strong evidence for the conjecture, showing that plectic Hodge filtration has a canonical splitting given by intersecting with simultaneous eigenspaces for the partial Frobenii. (In memory of Jan Nekovar)
Cite
@article{arxiv.2211.12078,
title = {Plectic structures in p-adic de Rham cohomology},
author = {David Loeffler and Sarah Livia Zerbes},
journal= {arXiv preprint arXiv:2211.12078},
year = {2025}
}
Comments
Revised version with minor corrections. To appear in Journal of Number Theory