ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)


Nonlinear modes

Mode localization in Fermi-Pasta-Ulam chains with arbitrary degree of nonlinearity

q-Breathers are exact periodic solutions of nonlinear acoustic chain systems, exponentially localized in the space of normal modes. Their presence determines the energy localization in initially excited modes, the absence of thermalization and persistence of quasi-linear spectrum. In the present paper we study the influence of the order of nonlinearity γ on the localization length in the q-space, delocalization threshold and scaling of these properties with the system size.

q-­breathers: from the fermi–pasta–ulam paradox to anomalous conductivity

The paper reviews the modern problems of nonlinear physics, where q-breathers theory finds its applications.