No-wandering-domain theorem
In mathematics, the no-wandering-domain theorem is a result on dynamical systems, proven by Dennis Sullivan in 1985.
The theorem states that a rational map f : Ĉ → Ĉ with deg(f) ≥ 2 does not have a wandering domain, where Ĉ denotes the Riemann sphere. More precisely, for every component U in the Fatou set of f, the sequence
will eventually become periodic. Here, f n denotes the n-fold iteration of f, that is,
![An image of the dynamical plane for f(z)=z+2\pi\sin(z).](http://up.wiki.x.io/wikipedia/commons/thumb/4/4f/Wandering_domains_for_the_entire_function_f%28z%29%3Dz%2B2%CF%80sin%28z%29.png/220px-Wandering_domains_for_the_entire_function_f%28z%29%3Dz%2B2%CF%80sin%28z%29.png)
The theorem does not hold for arbitrary maps; for example, the transcendental map has wandering domains. However, the result can be generalized to many situations where the functions naturally belong to a finite-dimensional parameter space, most notably to transcendental entire and meromorphic functions with a finite number of singular values.
References
[edit]- Lennart Carleson and Theodore W. Gamelin, Complex Dynamics, Universitext: Tracts in Mathematics, Springer-Verlag, New York, 1993, ISBN 0-387-97942-5 MR1230383
- Dennis Sullivan, Quasiconformal homeomorphisms and dynamics. I. Solution of the Fatou-Julia problem on wandering domains, Annals of Mathematics 122 (1985), no. 3, 401–18. MR0819553
- S. Zakeri, Sullivan's proof of Fatou's no wandering domain conjecture