Topological constraints and their breakdown in dynamical evolution

• Published in: Nonlinearity Vol. 25; no. 10; pp. R85 - R98
• Main Authors: Goldstein, Raymond E, Moffatt, H Keith, Pesci, Adriana I
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.10.2012; Institute of Physics
• Subjects: Biological; Dynamical systems; Dynamics; Evolution; Exact sciences and technology; General topology; Global analysis, analysis on manifolds; Invariance; Knots; Mathematical methods in physics; Mathematics; Nonlinear dynamics; Other topics in mathematical methods in physics; Physics; Sciences and techniques of general use; Topology; Topology. Manifolds and cell complexes. Global analysis and analysis on manifolds; Singularity; Topological dynamics; Deformation; Constraint; Nonlinear analysis; Invariance principle; Injection; Invariance; Knot; Dynamical system; Biological system; Breakdown; Minimum energy; Variety; Mathematical physics
• ISSN: 0951-7715; 1361-6544
• DOI: 10.1088/0951-7715/25/10/R85

A variety of physical and biological systems exhibit dynamical behaviour that has some explicit or implicit topological features. Here, the term 'topological' is meant to convey the idea of structures, e.g. physical knots, links or braids, that have some measure of invariance under continuous deformation. Dynamical evolution is then subject to the topological constraints that express this invariance. The simplest problem arising in these systems is the determination of minimum-energy structures (and routes towards these structures) permitted by such constraints, and elucidation of mechanisms by which the constraints may be broken. In more complex nonequilibrium cases there can be recurring singularities associated with topological rearrangements driven by continuous injection of energy. In this brief overview, motivated by an upcoming program on 'Topological Dynamics in the Physical and Biological Sciences' at the Isaac Newton Institute for Mathematical Sciences, we present a summary of this class of dynamical systems and discuss examples of important open problems.