Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-19T15:21:32.863Z Has data issue: false hasContentIssue false

Cubic critical portraits and polynomials with wandering gaps

Published online by Cambridge University Press:  31 August 2012

ALEXANDER BLOKH
Affiliation:
Department of Mathematics, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA (email: ablokh@math.uab.edu, ccurry@huntingdon.edu, overstee@math.uab.edu)
CLINTON CURRY
Affiliation:
Department of Mathematics, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA (email: ablokh@math.uab.edu, ccurry@huntingdon.edu, overstee@math.uab.edu)
LEX OVERSTEEGEN
Affiliation:
Department of Mathematics, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA (email: ablokh@math.uab.edu, ccurry@huntingdon.edu, overstee@math.uab.edu)

Abstract

Thurston introduced $\sigma _d$-invariant laminations (where $\sigma _d(z)$ coincides with $z^d:\mathbb S ^1\to \mathbb S ^1$, $d\ge 2$) and defined wandering $k$-gons as sets ${\mathbf {T}}\subset \mathbb S ^1$ such that $\sigma _d^n({\mathbf {T}})$ consists of $k\ge 3$ distinct points for all $n\ge 0$ and the convex hulls of all the sets $\sigma _d^n({\mathbf {T}})$ in the plane are pairwise disjoint. He proved that $\sigma _2$ has no wandering $k$-gons. Call a lamination with wandering $k$-gons a WT-lamination. In a recent paper, it was shown that uncountably many cubic WT-laminations, with pairwise non-conjugate induced maps on the corresponding quotient spaces $J$, are realizable as cubic polynomials on their (locally connected) Julia sets. Here we use a new approach to construct cubic WT-laminations with the above properties so that any wandering branch point of $J$ has a dense orbit in each subarc of $J$ (we call such orbits condense), and show that critical portraits corresponding to such laminations are dense in the space ${\mathcal A}_3$of all cubic critical portraits.

Type
Research Article
Copyright
Copyright © 2012 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Bielefield, B., Fisher, Y. and Hubbard, J. H.. The classification of critically preperiodic polynomials as dynamical systems. J. Amer. Math. Soc. 5 (1992), 721762.Google Scholar
[2]Blokh, A. and Levin, G.. An inequality for laminations, Julia sets and ‘growing trees’. Ergod. Th. & Dynam. Sys. 22 (2002), 6397.Google Scholar
[3]Blokh, A. and Oversteegen, L.. Wandering gaps for weakly hyperbolic polynomials. Complex Dynamics: Families and Friends. Ed. Schleicher, D.. A. K. Peters, Wellesley, MA, 2008, pp. 139168.Google Scholar
[4]Blokh, A., Curry, C. and Oversteegen, L.. Density of orbits in laminations and the space of critical portraits. Discrete Contin. Dyn. Syst. 32(6) (2012), 20272039.Google Scholar
[5]Branner, B. and Hubbard, J. H.. The iteration of cubic polynomials. Part I: The global topology of parameter space. Acta Math. 160 (1988), 143206.Google Scholar
[6]Fisher, Y.. The classification of critically preperiodic polynomials. PhD Thesis, Cornell University, 1989.Google Scholar
[7]Goldberg, L. and Milnor, J.. Fixed points of polynomial maps II: fixed point portraits. Ann. Sci. Éc. Norm. Supér. (4) 26 (1993), 5198.CrossRefGoogle Scholar
[8]Kiwi, J.. Wandering orbit portraits. Trans. Amer. Math. Soc. 354 (2002), 14731485.CrossRefGoogle Scholar
[9]Kiwi, J.. Real laminations and the topological dynamics of complex polynomials. Adv. Math. 184 (2004), 207267.Google Scholar
[10]Kiwi, J.. Combinatorial continuity in complex polynomial dynamics. Proc. Lond. Math. Soc. 91 (2005), 215248.Google Scholar
[11]Lavaurs, P.. Systèmes dynamiques holomorphes: explosion de points périodiques. PhD Thesis, Université Paris-Sud, 1989.Google Scholar
[12]Milnor, J.. Dynamics in One Complex Variable, 3rd edn. Princeton University Press, Princeton, NJ, 2006.Google Scholar
[13]Poirier, A.. On postcritically finite polynomials, parts I, II. Stony Brook IMS Preprints 1993–5 and 1993–7, 1993.Google Scholar
[14]Poirier, A.. Critical portraits for postcritically finite polynomials. Fund. Math. 203(2) (2009), 107163.CrossRefGoogle Scholar
[15]Thurston, W.. The combinatorics of iterated rational maps (1985). Complex Dynamics: Families and Friends. Ed. Schleicher, D.. A. K. Peters, Wellesley, MA, 2008, pp. 3137.Google Scholar