On irreps of a Hecke algebra of a non-reductive group

Abstract

We study irreducible representations of the Hecke algebra of the pair $({\rm PGL}_2 (F[\epsilon] / (\epsilon^2)) , {\rm PGL}_2 (\mathcal{O}[\epsilon] / (\epsilon^2)))$ where $F$ is a local non-Archimedean field of characteristic different than $2$ and $\mathcal{O} \subset F$ is its ring of integers. We expect to apply our analysis to the study of the spectrum of Hecke operators on the space of cuspidal functions on the space of principal ${\rm PGL}_2$-bundles on curves over rings $\mathbb{F}_q [\epsilon] / (\epsilon^2)$.