English

Modular supercuspidal lifts of weight $2$

Number Theory 2024-07-01 v2

Abstract

Let F/QF/\mathbb{Q} be any totally real number field and N\frak{N} an ideal of its ring of integers of norm NN and define, for every even nn, the [F:Q][F:\mathbb{Q}]-dimensional multiweight n=(n,...,n)\textbf{n}=(n,...,n). We prove that for a non CM Hilbert cuspidal Hecke eigenform for FF, say fSk(Γ0(N))f\in S_{\textbf{k}}(\Gamma_0(\frak{N})) with k>2k>2 even, and a prime p>max{k+1,6}p>\max\{k+1,6\} totally split in FF such that pNp\nmid N and such that the residual mod pp representation ρf\overline{\rho}_f satisfies that SL2(Fp)Im(ρf)\mathrm{SL}_2(\mathbb{F}_p)\subseteq \mathrm{Im}(\overline{\rho}_f), there exists a lift ρg\rho_g associated to a Hilbert modular cuspform for FF, say gS2(Np2,ϵ)g\in S_{\textbf{2}}(\frak{N}p^2,\epsilon) for some Nebentypus character ϵ\epsilon which is supercuspidal at each prime of FF over pp. We also observe that our techniques provide an alternative proof to the corresponding statement for classical Hecke cuspforms already proved by Khare \cite{khare} with classical techniques. Finally, we take the opportunity to include a corrigenda for \cite{dieulefait} which follows from our main result, which provides a congruence that puts the micro good dihedral prime in the level.

Keywords

Cite

@article{arxiv.2310.11522,
  title  = {Modular supercuspidal lifts of weight $2$},
  author = {Iván Blanco-Chacón and Luis Dieulefait},
  journal= {arXiv preprint arXiv:2310.11522},
  year   = {2024}
}

Comments

This is a generalisation of main result in our the former version to Hilbert modular forms of parallel weight to (with p totally split in F)

R2 v1 2026-06-28T12:53:45.349Z