%0 Journal Article %T Variational approach to a class of nonlinear oscillators with several limit cycles %A M. C. Depassier %A J. Mura %J Physics %D 2001 %I arXiv %R 10.1103/PhysRevE.64.056217 %X We study limit cycles of nonlinear oscillators described by the equation $\ddot x + \nu F(\dot x) + x =0$. Depending on the nonlinearity this equation may exhibit different number of limit cycles. We show that limit cycles correspond to relative extrema of a certain functional. Analytical results in the limits $\nu ->0$ and $\nu -> \infty$ are in agreement with previously known criteria. For intermediate $\nu$ numerical determination of the limit cycles can be obtained. %U http://arxiv.org/abs/nlin/0103034v1