English

Multivariable $(\varphi,\Gamma)$-modules and locally analytic vectors

Number Theory 2017-02-22 v8 Representation Theory

Abstract

Let KK be a finite extension of Qp\mathbf{Q}_p and let GK=Gal(Qˉp/K)G_K = \mathrm{Gal}(\bar{\mathbf{Q}}_p/K). There is a very useful classification of pp-adic representations of GKG_K in terms of cyclotomic (φ,Γ)(\varphi,\Gamma)-modules (cyclotomic means that Γ=Gal(K/K)\Gamma={\rm Gal}(K_\infty/K) where KK_\infty is the cyclotomic extension of KK). One particularly convenient feature of the cyclotomic theory is the fact that any (φ,Γ)(\varphi,\Gamma)-module is overconvergent. Questions pertaining to the pp-adic local Langlands correspondence lead us to ask for a generalization of the theory of (φ,Γ)(\varphi,\Gamma)-modules, with the cyclotomic extension replaced by an infinitely ramified pp-adic Lie extension K/KK_\infty / K. It is not clear what shape such a generalization should have in general. Even in the case where we have such a generalization, namely the case of a Lubin-Tate extension, most (φ,Γ)(\varphi,\Gamma)-modules fail to be overconvergent. In this article, we develop an approach that gives a solution to both problems at the same time, by considering the locally analytic vectors for the action of Γ\Gamma inside some big modules defined using Fontaine's rings of periods. We show that, in the cyclotomic case, we recover the ususal overconvergent (φ,Γ)(\varphi,\Gamma)-modules. In the Lubin-Tate case, we can prove, as an application of our theory, a folklore conjecture in the field stating that (φ,Γ)(\varphi,\Gamma)-modules attached to FF-analytic representations are overconvergent.

Keywords

Cite

@article{arxiv.1312.4753,
  title  = {Multivariable $(\varphi,\Gamma)$-modules and locally analytic vectors},
  author = {Laurent Berger},
  journal= {arXiv preprint arXiv:1312.4753},
  year   = {2017}
}

Comments

v8: final version, to appear in the Duke Math Journal. (In v2, the monodromy conjecture from v1 has been proved. In v3 and then v4, the restriction on ramification has been completely removed. In v5 the introduction has been rewritten. In v6 and v7 there are some improvements)

R2 v1 2026-06-22T02:29:24.395Z