Un autre calcul des fonctions inversibles sur l'espace sym\'etrique de Drinfeld

Abstract

In this article, we give an explicit description of the invertible functions on the Drinfeld symmetric space over $K$ a finite extension of $\mathbb{Q}_p$. We identify them with some distribution spaces over the profinite set of $K$-rationnal points of the projective space. The strategy consists of constructing a map from these distributions to the invertible functions following the methods of Schneider-Stuhler, Iovita-Spiess, de Shalit. We show that it is compatible with the isomorphisms they constructed to compute \'etale and de Rham cohomology in degree $1$ and that this property forces our desired map to be an isomorphism. In particular, we get a $\mathbb{Z}$-structure on these cohomology groups.