2002/10/28 by Jacques Sauloy, Sauloy, Jacques
Mathematics · #05A30 - 12H10 - 39A13 #FOS: Mathematics #Quantum Algebra (math.QA) #math.QA #msc:05A30 #msc:12H10 #msc:39A13
paper · pdf · doi:10.48550/arxiv.math/0210430
47 pages. Prepublication du Laboratoire Emile Picard n.249. See also http://picard.ups-tlse.fr
arxiv created 2002/10/28 · arxiv updated 2009/11/30
We show that the Newton polygon of a linear q-difference equation depends only on the corresponding q-difference module. We interpret the classical results of convergent factorisation of Adams-Birkhoff-Guenther in terms of the existence of a canonical filtration. Moreover, the associated graded module has excellent functorial (resp. tensorial) properties, whence its interest for classification (resp. for Galois theory).