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 Tools annual

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 Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Hénon-Heiles (HH) systems are Hamiltonian systems in R4 endowed with the standard symplectic form dP1 ∧ dQ1 + dP2 ∧ dQ2. The Hamiltonian function has the form H = 1 2 (P1 + P2) + V(Q1,Q2) whereV is a polynomial function. There are four nontrivial integral cases with quartic potential whose name in the literature isHH4 followed by three numbers giving the ratios of the coefficients of the quartic monomials: 1:2:1, 1:6:1, 1:6:8 and 1:12:16. The generalized HH systems are obtained adding inverse terms to the potential V , without destroying the integrability of the system.

A New Case of Separability in a Quartic Hénon-Heiles System