FM: 2005-19 (mp_arc 05-409; math.DS/0512026)

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

Guido Gentile
Dipartimento di Matematica, Università di Roma Tre
L. S. Leonardo Murialdo
00100 Roma, Italia
tel +39-06-54-888-226
e-mail: gentile@mat.uniroma3.it