$D$-modules arithm\'etiques, distributions et localisation

Let $p$ be a prime number, $V$ a discrete valuation ring of unequal caracteristics $(0,p)$, $G$ a smooth affine algebraic group over $Spec \,V$. Using partial divided powers techniques of Berthelot, we construct arithmetic distribution algebras, with level $m$, generalizing the classical construction of the distribution algebra. We also construct the weak completion of the classical distribution algebra. We then show that these distribution algebras can be identified with invariant arithmetic differential operators over $G$. We finally apply these constructions in the case of a reductive group and obtain a localization theorem for the sheaf of arithmetic differential operators on the formal flag variety obtained by $p$-adic completion, generalizing a previous result of Ardakov-Wadsley (for the level 0 and with some condition on $p$).