Parabolic induction in the homotopy category of pro-$p$ Iwahori-Hecke modules

Abstract

Let $G$ be the group of rational points of a split connected reductive group over a non-archimedean local field of residue characteristic $p$, and let $\mathcal{H}$ denote the pro-$p$ Iwahori-Hecke algebra of $G$ over a field of characteristic $p$. We study the parabolic induction functor for $\mathcal{H}$-modules in terms of the Gorenstein projective model structures introduced by Hovey. Let $\text{Ho}(\mathcal{H})$ denote the associated homotopy category of this model structure. We show that $\text{Ho}(\mathcal{H})$ and its thick subcategory generated by the essential images of finitely many parabolic induction functors are related via a recollement of triangulated categories. We then investigate the isomorphism classes of simple $\mathcal{H}$-modules in $\text{Ho}(\mathcal{H})$ and give a complete classification for simple supersingulars when $G={\mathrm{GL}}_n$.

arXiv comment57 pages; a few minor changes based on a referee report; final version; to appear in Mathematische Zeitschrift