Rotation numbers and symbolic dynamics

David Bowman, Ross Flek, Gregory Tycho Markowsky

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2 Citations (Scopus)


A degree c rotation set in [0, 1] is an ordered set {t1, . . . , tq} such that there is a
positive integer p such that cti(mod 1) = ti+p(mod q) for i = 1, . . . , q. The rotation number of the set is defined to be p/q. Goldberg has shown that for any rational number p/q ∈ (0, 1) there is a unique quadratic rotation set with rotation number p/q. This result was used by Goldberg and Milnor to study Julia sets of quadratic polynomials [8]. In this work, we provide an alternate proof of Goldberg’s result which employs symbolic dynamics. We also deduce a number of additional results from our method, including a characterization of the values of the elements of the rotation sets.
Original languageEnglish
Pages (from-to)227-234
Number of pages8
JournalAnnales Academiae Scientiarum Fennicae Mathematica
Publication statusPublished - 2015


  • Symbolic dynamics
  • rotation sets
  • complex dynamics
  • doubling map
  • combinatorial dynamics

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