A nonlinear system with weak dissipation under external force on   incommensurate frequency: coexistence of attractors
  The behaviour of the 2D model system - the Ikeda map - is investigated in the weakly dissipative regime under external forcing on the incommensurate frequency. Coexistence of a large number of stable invariant curves is shown. Dependence of the number of coexisting attractors on the external forcing amplitude and nonlinearity parameter is investigated. 
M.V. Pozdnyakov, A.V. Savin, D.V. Savin
nlin.CD