The integral geometric Satake equivalence in mixed characteristic

Abstract

Let $k$ be an algebraically closed field of characteristic $p$. Denote by $W(k)$ the ring of Witt vectors of $k$. Let $F$ denote a totally ramified finite extension of $W(k)[1/p]$ and $\mathcal{O}$ the its ring of integers. For a connected reductive group scheme $G$ over $\mathcal{O}$, we study the category $P_{L^{+}G}(G{r}_G,\Lambda )$ of $L^{+}G$-equivariant perverse sheaves in $\Lambda$-coefficient on the affine Grassmannian $G{r}_G$ where $\Lambda ={\mathbb{Z}}_{\ell }$ and ${\mathbb{F}}_{\ell }$ and prove it is equivalent as a tensor category to the category of finitely generated $\Lambda$-representations of the Langlands dual group of $G$.