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IkedaDelay

Systems / DDEs / Delayed systems

A delayed optical-cavity model — sinusoidal nonlinearity with memory, chaotic for modest delay.

delay · DDE1 dimensionchaotic

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Definition

\[ \begin{aligned} \dot{y_{0}} &= - c y_{0}{\left(t \right)} - \mu \sin{\left(x_{0} - y_{0}{\left(t - \tau \right)} \right)} \end{aligned} \]

Parameters

Symbol Default Role
c 1 linear relaxation (damping) rate of the cavity field
mu -20 feedback strength
tau 2 round-trip delay
x0 0 phase offset (detuning) of the nonlinear feedback

Properties

Lyapunov spectrum
TODO — DDE Lyapunov not computed at build time
Kaplan–Yorke dimension
TODO — requires a numeric Lyapunov spectrum
Divergence ∇·f
$\nabla\!\cdot f = 0$
constant
Equilibria
TODO — fixed_points failed: NotImplementedError

Define it in TSDynamics

import tsdynamics as ts

sys = ts.systems.IkedaDelay()
traj = sys.integrate(final_time=500.0, dt=0.5)

# DDE Lyapunov uses the infinite-dimensional-history estimator:
exps = sys.lyapunov_spectrum(n_exp=1, dt=0.5, ic=traj.y[-1])

Reference

Ikeda & Matsumoto (1987), Physica D 29, 223-235

BibTeX
@misc{ikedadelay,
  title = {IkedaDelay system},
  note = {Ikeda & Matsumoto (1987), Physica D 29, 223-235}
}