English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Upon initial excitation of a few normal modes the energy distribution amongall modes of a nonlinear atomic chain (the Fermi-Pasta-Ulam model) exhibitsexponential localization on large time scales. At the same time resonantanomalies (peaks) are observed in its weakly excited tail for long timespreceding equipartition. We observe a similar resonant tail structure also forexact time-periodic Lyapunov orbits, coined q-breathers due to theirexponential localization in modal space. We give a simple explanation for thisstructure in terms of superharmonic resonances. The resonance analysis agreesvery well with numerical results and has predictive power. We extend apreviously developed perturbation method, based essentially on aPoincare-Lindstedt scheme, in order to account for these resonances, and inorder to treat more general model cases, including truncated Toda potentials.Our results give qualitative and semiquantitative account for the superharmonicresonances of q-breathers and natural packets

Tail resonances of Fermi-Pasta-Ulam q-breathers and their impact on the pathway to equipartition