An analogue of $Γ$-function for irreducible cuspidal representations of the group $\mathrm{GL}(2)$ over a two-dimensional local field

Abstract

Let $\mathbf F$ be a non-archimedian local field of odd residue characteristic, ${\mathcal O}={\mathbf F}[\![t]\!]\subset{\mathcal K}={\mathbf F}(\!(t)\!)$. We consider the subgroup $\widehat{\mathrm{GL}}(2,{\mathcal O})={\mathcal K}^\times\cdot{\mathrm{GL}}(2,{\mathcal O})\subset{\mathrm{GL}}(2,{\mathcal K})$, and the normalizer ${\mathrm{GL}}'(2,{\mathcal O})\subset{\mathrm GL}(2,{\mathcal K})$ of an Iwahori subgroup $I\subset{\mathrm{GL}}(2,{\mathcal K})$. We calculate the $Γ$-functions for irreducible special representations of $\widehat{\mathrm{GL}}(2,{\mathcal O})$ and ${\mathrm{GL}}'(2,{\mathcal O})$.