Some remarks concerning weakly disconjugate
linear Hamiltonian systems,
with Roberta Fabbri, Russell
Johnson and Sylvia Novo,
J.
Math. Anal. Appl. 380
(2011), 853-864.
We study properties of weakly disconjugate
linear Hamiltonian systems. We characterize
this concept in terms of a nonoscillation condition.
We then show how to approximate a
weakly disconjugate system by one with an exponential
dichotomy.