Author : Guido Gentile
Title: Resummation of perturbation series and reducibility for Bryuno skew-product flows
Abstract: We consider skew-product systems on T^d x SL(2,R) for Bryuno base flows close to constant coefficients, depending on a parameter, in any dimension d, and we prove reducibility for a large measure set of values of the parameter. The proof is based on a resummation procedure of the formal power series for the conjugation, and uses techniques of renormalisation group in quantum field theory.
Keywords: Skew-product, Schroedinger equation, Reducibility, Perturbation Series, Cancellations, Bryuno condition, Multiscale analysis, Renormalisation Group, Quantum Field Theory
Dipartimento di Matematica, Università di Roma Tre
L. S. Leonardo Murialdo
00100 Roma, Italia