Validated study of the existence of short cycles for chaotic systems using symbolic dynamics and interval tools

Zbigniew Galias, Warwick Tucker

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)


We show that, for a certain class of systems, the problem of establishing the existence of periodic orbits can be successfully studied by a symbolic dynamics approach combined with interval methods. Symbolic dynamics is used to find approximate positions of periodic points, and the existence of periodic orbits in a neighborhood of these approximations is proved using an interval operator. As an example, the Lorenz system is studied; a theoretical argument is used to prove that each periodic orbit has a distinct symbol sequence. All periodic orbits with the period p ≤ 16 of the Poincaré map associated with the Lorenz system are found. Estimates of the topological entropy of the Poincaré map and the flow, based on the number and flow-times of short periodic orbits, are calculated. Finally, we establish the existence of several long periodic orbits with specific symbol sequences.

Original languageEnglish
Pages (from-to)551-563
Number of pages13
JournalInternational Journal of Bifurcation and Chaos
Issue number2
Publication statusPublished - Feb 2011
Externally publishedYes


  • interval arithmetic
  • Lorenz system
  • Periodic orbit
  • symbolic dynamics

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