title: Chaos in two-loop negative feedback systems.
abstract: Multiloop delayed negative feedback systems, with each feedback loop having its own characteristic time lag (delay), are used to describe a great variety of systems: optical systems, neural networks, physiological control systems, etc. Previous investigations have shown that if the number of delayed feedback loops is greater than two, the system can exhibit complex dynamics and chaos, but in the case of two delayed loops only periodic solutions were found. Here we show that a period-doubling cascade and chaotic dynamics are also found in systems with two coupled delayed negative feedback loops.
authors.affiliation: Instituto do Coração, Universidade de São Paulo, Avenida Dr. Eneas de Carvalho Aguiar, 44, 05403-000 São Paulo, São Paulo, Brazil.
authors.forename: J C
authors.initials: JC
authors.lastname: Bastos de Figueiredo
authors.forename: L
authors.initials: L
authors.lastname: Diambra
authors.forename: Leon
authors.initials: L
authors.lastname: Glass
authors.forename: C P
authors.initials: CP
authors.lastname: Malta
mesh_terms: D001703:Biophysics / Q000379:methods*; D015233:Models, Statistical; D008962:Models, Theoretical; D017711:Nonlinear Dynamics