English

Lifting Galois representations to ramified coefficient fields

Number Theory 2015-02-27 v2

Abstract

Let p>5p>5 be a prime integer and K/QpK/\mathbb{Q}_p a finite ramified extension with ring of integers O\mathcal{O} and uniformizer π\pi. Let n>1n>1 be a positive integer and ρn:GQGL2(O/πn)\rho_n:G_\mathbb{Q} \to \text{GL}_2(\mathcal{O}/\pi^n) be a continuous Galois representation. In this article we prove that under some technical hypotheses the representation ρn\rho_n can be lifted to a representation ρ:GQGL2(O)\rho:G_\mathbb{Q} \to \text{GL}_2(\mathcal{O}). Furthermore, we can pick the lift restriction to inertia at any finite set of primes (at the cost of allowing some extra ramification) and get a deformation problem whose universal ring is isomorphic to W(F)[[X]]W(\mathbb{F})[[X]]. The lifts constructed are "nearly ordinary" (not necessarily Hodge-Tate) but we can prove the existence of ordinary modular points (up to twist).

Keywords

Cite

@article{arxiv.1409.2211,
  title  = {Lifting Galois representations to ramified coefficient fields},
  author = {Maximiliano Camporino},
  journal= {arXiv preprint arXiv:1409.2211},
  year   = {2015}
}

Comments

16 pages

R2 v1 2026-06-22T05:50:52.352Z