English

Tame class field theory over local fields

Algebraic Geometry 2026-01-21 v2

Abstract

For a quasi-projective scheme XX admitting a smooth compactification over a local field of residue characteristic p>0p > 0, we construct a continuous reciprocity homomorphism from a tame class group to the abelian tame etale fundamental group of XX. We describe the prime-to-pp parts of its kernel and cokernel. This generalizes the higher dimensional unramified class field theory over local fields by Jannsen-Saito and Forre. We also prove a finiteness theorem for the geometric part of the abelian tame etale fundamental group, generalizing the results of Grothendieck and Yoshida for the unramified fundamental group.

Keywords

Cite

@article{arxiv.2209.02953,
  title  = {Tame class field theory over local fields},
  author = {Rahul Gupta and Amalendu Krishna and Jitendra Rathore},
  journal= {arXiv preprint arXiv:2209.02953},
  year   = {2026}
}

Comments

Substantial revision, 68 pages. A version of this paper is accepted to appear in Amer. J. Math

R2 v1 2026-06-28T00:51:21.437Z