D\'ecomposition au-dessus des param\`etres de Langlands elliptiques

Abstract

We prove that, over any elliptic global Langlands parameter $\sigma$, the cuspidal cohomology groups of moduli stacks of shtukas are given by a formula involving a finite dimensional representation of the centralizer of $\sigma$. It is a first step in the direction of Arthur-Kottwitz conjectures.