Université de Versailles-St Quentin, Laboratoire de Mathématiques, 45 avenue des États-Unis 78035 Versailles cedex, France
e-mail: divizio[at]math.cnrs.fr          Office: bâtiment Fermat, office 3305

with Charlotte Hardouin, with a preface to Part IV by Anne Granier. To appear in Memoirs of the American Methematical Society. 77 pages.  


We give a complete answer to the analogue of Grothendieck conjecture on p-curvatures for q-difference equations defined over K(x), where K is any finitely generated extension of Q and q\in K can be either a transcendental or an algebraic number. This generalizes the results in [DV02], proved under the assumption that K is a number field and q an algebraic number. The results also hold for a field K which is a finite extension of a purely transcendental extension k(q) of a perfect field k. In Part 3, we consider two Galois groups attached to a q-difference module M over K(x): (1) the intrinsic Galois group Gal(M), in the sense of [Kat82]; (2) if char K=0, the intrinsic differential Galois group Gal^D(M), which is a Kolchin differential algebraic group. We deduce an arithmetic description of Gal(M) (resp. Gal^D(M)). In Part 4, we show that the Galois D-groupoid [Gra09] of a nonlinear q-difference system generalizes Gal^D(M).

ArXiv:1002.4839. (This article also contains the results of the unpublished preprints ArXiv: 1205.16941205.1692.)