IkedaDelay¶
Systems / DDEs / Delayed systems
A delayed optical-cavity model — sinusoidal nonlinearity with memory, chaotic for modest delay.
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
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