On Urabe's criteria of isochronicity
arXiv:nlin/0003065 · doi:10.1088/0305-4470/32/7/017
Abstract
We give a short proof of Urabe's criteria for the isochronicity of periodical solutions of the equation . We show that apart from the harmonic oscillator there exists a large family of isochronous potentials which must all be non-polynomial and not symmetric (an even function of the coordinate x).
arXiv comment8 pages