Periodic Perturbations of a Nonconservative Center

Resumo

Small time-periodic perturbations of an oscillator whose restoring force has a conservative as well as a dissipative component are studied. The stability of the equilibrium and the bifurcation of an invariant two-dimensional torus from the equilibrium are considered. The focus quantity and the bifurcation equation determining the stability and branching character of the equilibrium are constructed.