TITLE:
Effective Stability in Reversible Systems

AUTHORS:
Amadeu Delshams(1) and Jose Tomas Lazaro(2)


(1) Dept. de Matematica Aplicada I (ETSEIB), Universitat Politecnica de
    Catalunya, Diagonal 647, 08028 Barcelona (Spain).
    E-mail: amadeu@ma1.upc.es

(2) Dept. de Matematica Aplicada i Telematica, Universitat Politecnica de
    Catalunya, Victor Balaguer s/n E-08800 Vilanova i la Geltru, Barcelona 
    (Spain).


ABSTRACT:
In this paper we present a procedure to put in normal form a
nearly-integrable reversible system, not necessarily a Hamiltonian
system. Furthermore, non-resonant stability estimates are obtained. As
an application we discuss the case of $n$ harmonic oscillators with
frequencies satisfying Diophantine conditions.