English

A theorem on meromorphic descent and the specialization of the pro-\'etale fundamental group

Algebraic Geometry 2022-02-08 v3 Algebraic Topology Category Theory Number Theory

Abstract

Given a Noetherian formal scheme X^\hat X over Spf(R){\rm Spf}(R), where RR is a complete DVR, we first prove a theorem of meromorphic descent along a possibly infinite cover of X^\hat{X}. Using this we construct a specialization functor from the category of continuous representations of the pro-\'etale fundamental group of the special fiber to the category of FF-divided sheaves on the generic fiber. This specialization functor partially recovers the specialization functor of the \'etale fundamental groups. We also express the pro-\'etale fundamental group of a connected scheme XX of finite type over a field as coproducts and quotients of the free group and the \'etale fundamental groups of the normalizations of the irreducible components of XX and those of its singular loci.

Keywords

Cite

@article{arxiv.2103.11543,
  title  = {A theorem on meromorphic descent and the specialization of the pro-\'etale fundamental group},
  author = {Marcin Lara and Jiu-Kang Yu and Lei Zhang},
  journal= {arXiv preprint arXiv:2103.11543},
  year   = {2022}
}