In mathematics, Fatou components are components of the Fatou set. They were named after Pierre Fatou.
If f is a rational function
defined in the extended complex plane, and if it is a nonlinear function (degree > 1)
then for a periodic component of the Fatou set, exactly one of the following holds:
The components of the map contain the attracting points that are the solutions to . This is because the map is the one to use for finding solutions to the equation by Newton–Raphson formula. The solutions must naturally be attracting fixed points.
The map
and t = 0.6151732... will produce a Herman ring. [2] It is shown by Shishikura that the degree of such map must be at least 3, as in this example.
If degree d is greater than 2 then there is more than one critical point and then can be more than one type of component
In case of transcendental functions there is another type of periodic Fatou components, called Baker domain: these are "domains on which the iterates tend to an essential singularity (not possible for polynomials and rational functions)" [3] [4] one example of such a function is: [5]
Transcendental maps may have wandering domains: these are Fatou components that are not eventually periodic.