Morse Predecomposition of an Invariant Set

• Published in: Qualitative theory of dynamical systems 2025, Vol.24 (1), p.5, Article 5
• Main Authors: Lipiński, Michał, Mischaikow, Konstantin, Mrozek, Marian
• Format: Article
• Language: English
• Subjects: Difference and Functional Equations; Dynamical Systems and Ergodic Theory; Mathematics; Mathematics and Statistics
• ISSN: 1575-5460; 1662-3592; 1662-3592
• DOI: 10.1007/s12346-024-01144-3

Motivated by the study of recurrent orbits and dynamics within a Morse set of a Morse decomposition we introduce the concept of Morse predecomposition of an isolated invariant set within the setting of both combinatorial and classical dynamical systems. While Morse decomposition summarizes solely the gradient part of a dynamical system, the developed generalization extends to the recurrent component as well. In particular, a chain recurrent set, which is indecomposable in terms of Morse decomposition, can be represented more finely in the Morse predecomposition framework. This generalization is achieved by forgoing the poset structure inherent to Morse decomposition and relaxing the notion of connection between Morse sets (elements of Morse decomposition) in favor of what we term ’links’. We prove that a Morse decomposition is a special case of Morse predecomposition indexed by a poset. Additionally, we show how a Morse predecomposition may be condensed back to retrieve a Morse decomposition.