title: Variational approach to a class of nonlinear oscillators with several limit cycles.
abstract: We study limit cycles of nonlinear oscillators described by the equation x + nuF(x) + x = 0 with F an odd function. Depending on the nonlinearity, this equation may exhibit one or more limit cycles. We show that limit cycles correspond to relative extrema of a certain functional. Analytical results in the limits nu-->0 and nu-->infinity are in agreement with previously known criteria. For intermediate nu, numerical determination of the limit cycles can be obtained.
authors.affiliation: Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile.
authors.forename: M C
authors.initials: MC
authors.lastname: Depassier
authors.forename: J
authors.initials: J
authors.lastname: Mura