English

Lubin-Tate and multivariable $(\varphi,\mathcal{O}_K^{\times})$-modules in dimension 2

Number Theory 2024-04-02 v1

Abstract

Let pp be a prime number, KK a finite unramified extension of Qp\mathbb{Q}_p and F\mathbb{F} a finite extension of Fp\mathbb{F}_p. For ρ\overline{\rho} any reducible two-dimensional representation of Gal(K/K)\operatorname{Gal}(\overline{K}/K) over F\mathbb{F}, we compute explicitly the associated \'etale (φ,OK×)(\varphi,\mathcal{O}_K^{\times})-module DA(ρ)D_A^{\otimes}(\overline{\rho}) defined by Breuil-Herzig-Hu-Morra-Schraen. Then we let π\pi be an admissible smooth representation of GL2(K)\operatorname{GL}_2(K) over F\mathbb{F} occurring in some Hecke eigenspaces of the mod pp cohomology and ρ\overline{\rho} be its underlying two-dimensional representation of Gal(K/K)\operatorname{Gal}(\overline{K}/K) over F\mathbb{F}. Assuming that ρ\overline{\rho} is maximally non-split, we prove under some genericity assumption that the associated \'etale (φ,OK×)(\varphi,\mathcal{O}_K^{\times})-module DA(π)D_A(\pi) defined by Breuil-Herzig-Hu-Morra-Schraen is isomorphic to DA(ρ)D_A^{\otimes}(\overline{\rho}). This extends the results of Breuil-Herzig-Hu-Morra-Schraen, where ρ\overline{\rho} was assumed to be semisimple.

Keywords

Cite

@article{arxiv.2404.00396,
  title  = {Lubin-Tate and multivariable $(\varphi,\mathcal{O}_K^{\times})$-modules in dimension 2},
  author = {Yitong Wang},
  journal= {arXiv preprint arXiv:2404.00396},
  year   = {2024}
}

Comments

43 pages

R2 v1 2026-06-28T15:39:09.568Z