Wandering Domains, Hyperbolicity, and Thurston Algorithms
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Definitions and mathematical statement
For a transcendental entire map $f$, its Fatou set is the normality locus of the iterates. A wandering domain is a Fatou component whose successive forward Fatou components are distinct. Limit functions of $\{f^n|_U\}$ mean subsequential locally uniform limits in the intended, usually spherical, topology. The postsingular set is conventionally \[ P(f)=\overline{\bigcup_{m\geq0}f^m(S(f))}, \] where $S(f)$ is the closed set of finite critical and asymptotic values. Nonrecurrence of a critical point ordinarily means that it does not belong to the omega-limit set of its forward orbit; the source's full nonrecurrence hypotheses are not supplied.The record bundles these questions:
- If $f$ has a wandering domain $U$, can its limit functions there be bounded? It is unspecified whether bounded means individually bounded, finite rather than infinite, or uniformly bounded as a collection.
- If $P(f)$ is bounded, can $f$ have wandering domains? Ask also for the stated variant in which all critical points are nonrecurrent; no assumption excluding asymptotic values is added.
- For $f_{\lambda,k}(z)=\lambda z e^z+k$, with $\lambda=e^{2\pi i\theta}$ and the required nonrecurrence assumptions, can $f_{\lambda,k}$ have a Siegel disk, that is, a maximal domain on which an iterate is conformally an irrational rotation? The assumptions are referred to but not actually stated, and the parameter ranges are incomplete.
- Is the complement of the hyperbolicity locus precompact in $\operatorname{Rat}_d$ modulo Möbius conjugacy? Here $\operatorname{Rat}_d$ denotes degree-$d$ rational maps; under the usual degree-$d\geq2$ convention hyperbolicity means that every critical orbit converges to an attracting cycle. Precompactness asks for compact closure in the intended moduli space, not automatically in an added compactification.
- For $f_\lambda(z)=\lambda e^z$, characterize parameters for which the nonescaping set is connected, and separately those for which that set together with $\{\infty\}$ is connected. Under the usual convention the escaping set is $I(f)=\{z:|f^m(z)|\to\infty\}$, and nonescaping is its complement, not necessarily the bounded-orbit set. The second topology is that of the Riemann sphere.
- Can Thurston's algorithm be implemented in \[ O\left((\deg(f)+|\Omega_f|)^n\right) \] iterations, producing either a point sufficiently close to a fixed point of the pullback map or a Thurston obstruction? The input class, $\Omega_f$, exponent parameter $n$, closeness tolerance, metric, and meaning of algorithmic cost are unspecified. The printed iteration bound is retained without replacing it by a newly chosen complexity model.
Short English statement
The source groups questions about wandering domains, bounded postsingular sets, Siegel disks in an explicit entire family, rational-map moduli, exponential connectivity and the complexity of Thurston's algorithm. Every clause is retained with its source-specific gaps.Sources
- Local UnsolvedMath registry, permanent ID $30001091$, source code
catalogue entry, "Wandering Domains, Hyperbolicity, and Thurston Algorithms." Registry curation: Ulam AI / UnsolvedMath Contributors, CC BY 4.0; underlying sources retain their supplied provenance. - Trends and Developments in Complex Dynamics (2009), Oberwolfach Reports, pp. 2703--2762, DOI https://doi.org/10.4171/owr/2008/48.
- Supplied literature triage,
literature_checked_at: 2026-08-21: labeled open; says the entry is a bundle of transcendental and rational dynamics questions rather than a single resolved assertion, and the listed parameter-space and algorithmic questions remain an open research bundle. This is supplied dated curation, not independently verified, and gives no precise per-clause status.
Statement licence: CC-BY-SA-4.0 · Source file
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