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Ordered orbits of the shift, square roots, and the devil's staircase

Published online by Cambridge University Press:  24 October 2008

Shaun Bullett
Affiliation:
School of Mathematical Sciences, Queen Mary and Westfield College, Mile End Road, LondonE1 4NS
Pierrette Sentenac
Affiliation:
Mathématique, Bâtiment 425, Université de Paris-Sud, 91405 Orsay, France

Abstract

An orbit of the shift σ: t ↦ 2t on the circle = ℝ/ℤ is ordered if and only if it is contained in a semi-circle Cμ = [μ, μ+½]. We investigate the ‘devil's staircase’ associating to each μ ε the rotation number ν of the unique minimal closed σ-invariant set contained in Cμ; we present algorithms for μ in terms of ν, and we prove (after Douady) that if ν is irrational then μ is transcendental. We apply some of this analysis to questions concerning the square root map, and mode-locking for families of circle maps, we generalize our algorithms to orbits of the shift having ‘sequences of rotation numbers’, and we conclude with a characterization of all orders of points around realizable by orbits of σ.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1994

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References

REFERENCES

[1]Arnol'd, V. I.. Small denominators. I. Mapping the circle onto itself. Akad. Nauk. SSSR, Ser. Math. 25 (1961), 2186, and Geometrical methods in the theory of ordinary differential equations (Springer-Verlag, 1983).Google Scholar
[2]Atela, P.. Bifurcations of dynamic rays in complex polynomials of degree two. Erg. Th. Dyn. Syst. 12 (1992), 401423.CrossRefGoogle Scholar
[3]Bandt, C. and Keller, K.. Symbolic dynamics for angle-doubling on the circle. I. The topology of locally connected Julia sets. In Lecture Notes in Mathematics 1514 (Springer Verlag, 1992), 123.Google Scholar
[4]Bandt, C. and Keller, K.. Symbolic dynamics for angle-doubling on the circle. II. Symbolic dynamics of the abstract Mandelbrot set, preprint.Google Scholar
[5]Bandt, C. and Keller, K.. Symbolic dynamics for angle-doubling on the circle. III. Sturmian sequences and the quadratic map, preprint.Google Scholar
[6]Branner, B.. The Mandelbrot set. In Proceedings of Symposia in Applied Mathematics 39 (1989) (AMS Providence, Rhode Island).Google Scholar
[7]Douady, A.. Algorithm for computing angles in the Mandelbrot set. In Chaotic Dynamics and Fractals (Academic Press, 1986).Google Scholar
[8]Douady, A. and Hubbard, J. H.. Itération des polynomes quadratiques complexes. C.R. Acad. Sci. Paris, t294, Seri. I (1982), 123126.Google Scholar
[9]Douady, A. and Hubbard, J. H.. Etude dynamique des polynomes complexes. (Publ. Math. Orsay I 1984, II, 1985).Google Scholar
[10]Douady, A. and Hubbard, J. H.. On the dynamics of polynomial-like mappings. Ann. Sci. Ec. Norm. Sup. (Paris) 18 (1985), 287343.Google Scholar
[11]Gambaudo, J. M., Lanford, O. and Tresser, C.. Dynamique symbolique des rotations. C.R. Acad. Sci. Paris, t299 (1984), 823825.Google Scholar
[12]Glendinning, P. A. and Sparrow, C. T.. Prime and renormalisable kneading invariants and the dynamics of expanding Lorenz maps. Physic 62D (1993), 2250.Google Scholar
[13]Goldberg, L. R.. Fixed points of polynomial maps I. Ann Ec. Norm. Sup. 25 (1992), 679685.CrossRefGoogle Scholar
[14]Goldberg, L. R. and Milnor, J.. Fixed points of polynomial maps II. Ann. Ec. Norm. Sup. 26 (1993), 5198.Google Scholar
[15]Hubbard, J. H. and Sparrow, C. T.. The classification of topologically expansive Lorenz maps. Comm. Pure App. Math. 43 (1990), 431444.CrossRefGoogle Scholar
[16]Lavaurs, P.. Une description combinatoire de l'involution definie par M sur les rationnels a denominateur impair. C.R. Acad. Sci. Paris, t303 (1986), 143146.Google Scholar
[17]Morse, M. and Hedlund, G. A.. Symbolic Dynamics II. Sturmian Trajectories, Am. J. Math. 62 (1940), 142.CrossRefGoogle Scholar
[18]Roth, K. F.. Rational approximations to algebraic numbers. Mathematika 2 (1955), 120Google Scholar
Roth, K. F.. corrigendum, Mathematika 2 (1955), 168.CrossRefGoogle Scholar
[19]Veerman, J. J. P.. Symbolic dynamics and rotation numbers. Physica 134A (1986), 543576.Google Scholar
[20]Veerman, J. J. P.. Symbolic dynamics of order-preserving orbits. Physica 29D (1987), 191201.Google Scholar