title: Covariant hydrodynamic Lyapunov modes and strong stochasticity threshold in Hamiltonian lattices.
abstract: We scrutinize the reliability of covariant and Gram-Schmidt Lyapunov vectors for capturing hydrodynamic Lyapunov modes (HLMs) in one-dimensional Hamiltonian lattices. We show that, in contrast with previous claims, HLMs do exist for any energy density, so that strong chaos is not essential for the appearance of genuine (covariant) HLMs. In contrast, Gram-Schmidt Lyapunov vectors lead to misleading results concerning the existence of HLMs in the case of weak chaos.
authors.affiliation: SEPI ESIME-Culhuacán, Instituto Politécnico Nacional, Distrito Federal 04430, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Romero-Bastida
authors.forename: Diego
authors.initials: D
authors.lastname: Pazó
authors.forename: Juan M
authors.initials: JM
authors.lastname: López