Title: Local analytic classification of q-difference equations
Description: We essentially achieve Birkhoff's program for q-difference equations by giving three different descriptions of the moduli space of isoformal analytic classes. This involves an extension of Birkhoff-Guenther normal forms, q-analogues of the so-called Birkhoff-Malgrange--Sibuya theorems and a new theory of summation. The results were announced in various seminars and conferences between 2004 and 2006.
Subjects: Difference equations, Riemann-Hilbert problems