Velocity-dependent KAM islands

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Processo FAPESP: 06/51653-0

Processo FAPESP: 07/57992

We revisit the non-dissipative time-dependent annular billiard and we consider the chaotic dynamics in two planes of conjugate variables in order to describe the behavior of the growth, or saturation, of the mean velocity of an ensemble of particles. We observed that the changes in the 4-d phase space occur without changing any parameter. They occur depending on where the initial conditions start. The emerging KAM islands interfere in the behavior of the particle dynamics especially in the Fermi acceleration mechanism. We show that Fermi acceleration can be suppressed, without dissipation, even considering the non-dissipative energy context. (C) 2011 Published by Elsevier Ltd.