On the period function of planar systems with unknown normalizers
Authors:
M. Sabatini
Affiliation:
Department of Mathematics, University of Trento, via Sommarive 14, I-38050, Povo, Italy
Abstract:
A necessary and sufficient condition for the period function's monotonicity on a period annulus is given. The approach is based on the theory of normalizers, but is applicable without actually knowing a normalizer. Some applications to polynomial and Hamiltonian systems are presented.