Dynamics of a class of 3-dimensional Lotka-Volterra Systems

We provide the complete dynamics of the Lotka-Volterra differential system x˙ = x(ay - cz), y˙ = y(bz - ax), z˙ = z(cx - by), where a, b, c are positive parameters and x, y, z are in the positive octant of R3. In particular we show that this system is completely integrable, i.e. it has two independe...

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Bibliographic Details
Authors: Llibre, Jaume|||0000-0002-9511-5999; Valls, Clàudia|||0000-0001-8279-1229
Format: Article
Publication date:2023
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:301150
Online Access:https://ddd.uab.cat/record/301150
Access Level:Open access
Keyword:Lotka-Volterra system
Invariant
Global dynamics
Phase portrait
Description
Summary:We provide the complete dynamics of the Lotka-Volterra differential system x˙ = x(ay - cz), y˙ = y(bz - ax), z˙ = z(cx - by), where a, b, c are positive parameters and x, y, z are in the positive octant of R3. In particular we show that this system is completely integrable, i.e. it has two independent first integrals. Fixing one of these first integrals we obtain invariant triangles in the positive octant of R3. The dynamics of the system on each one of these invariant triangles is given by an equilibrium point surrounded by periodic orbits, i.e. by a center. In short all the orbits of these system are either equilibrium points, or periodic orbits. This nonlinear differential system models, under the conservation of mass, a cycle ofirreversible autocatalytic reactions between the different states of three macromolecules and allows to describe stable chemical oscillations.