Mode Locking
A phenomenon in which a system being forced at an irrational period undergoes rational, periodic motion which persists for a finite range of forcing values. It may occur for strong couplings between natural and forcing oscillation frequencies.
The phenomenon can be exemplified in the circle map when, after q iterations of the map, the new angle differs from the initial value by a rational number
This is the form of the unperturbed circle map with the map winding number
For Omega not a rational number, the trajectory is quasiperiodic.
See also
ChaosExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Mode Locking." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ModeLocking.html