English

Pro-$p$ Iwahori-Hecke modules in semisimple rank one and singularity categories

Representation Theory 2026-05-01 v3 Number Theory

Abstract

Let F\mathfrak{F} be a non-archimedean local field of residue characteristic pp and GG be one of the groups GL2(F)\mathrm{GL}_2(\mathfrak{F}), SL2(F)\mathrm{SL}_2(\mathfrak{F}) or PGL2(F)\mathrm{PGL}_2(\mathfrak{F}). Let HG\mathcal{H}_G denote the pro-pp Iwahori-Hecke algebra of GG over Fp\overline{\mathbb{F}}_p. We study the homotopy category Ho(HG)\mathrm{Ho}(\mathcal{H}_G) of Hovey's Gorenstein projective model structure on the category of HG\mathcal{H}_G-modules and relate it to the singularity category Sing(Xq,G)\mathrm{Sing}(X_{q,\mathbf{G}}) of an explicit scheme. When G=GL2(F)G=\mathrm{GL}_2(\mathfrak{F}), this scheme was first introduced by Dotto-Emerton-Gee \cite{DEG22}. We obtain in that case an equivalence Ho(HGL2)Sing(Xq,GL2)\mathrm{Ho}(\mathcal{H}_{\mathrm{GL}_2})\simeq \mathrm{Sing}(X_{q,\mathrm{GL}_2}) and recover from this Grosse-Kl\"onne's mod-pp Langlands correspondence for Hecke modules \cite{GK20}, building on work of P\'epin-Schmidt \cite{PeSch25_2}. We furthermore describe Ho(HG)\mathrm{Ho}(\mathcal{H}_G) completely explicitly when G=SL2(F)G=\mathrm{SL}_2(\mathfrak{F}) or PGL2(F)\mathrm{PGL}_2(\mathfrak{F}), and make additional computations in the GL2\mathrm{GL}_2 case.

Keywords

Cite

@article{arxiv.2604.11235,
  title  = {Pro-$p$ Iwahori-Hecke modules in semisimple rank one and singularity categories},
  author = {Nicolas Dupré},
  journal= {arXiv preprint arXiv:2604.11235},
  year   = {2026}
}

Comments

31 pages; minor revisons, some references added; comments welcome