Cyclic complexity of words

Gabriele Fici, Marinella Sciortino, Julien Cassaigne, Luca Q. Zamboni

Risultato della ricerca: Articlepeer review

13 Citazioni (Scopus)


We introduce and study a complexity function on words cx(n), called cyclic complexity, which counts the number of conjugacy classes of factors of length n of an infinite word x. We extend the well-known Morse–Hedlund theorem to the setting of cyclic complexity by showing that a word is ultimately periodic if and only if it has bounded cyclic complexity. Unlike most complexity functions, cyclic complexity distinguishes between Sturmian words of different slopes. We prove that if x is a Sturmian word and y is a word having the same cyclic complexity of x, then up to renaming letters, x and y have the same set of factors. In particular, y is also Sturmian of slope equal to that of x. Since cx(n)=1 for some n≥1 implies x is periodic, it is natural to consider the quantity liminfn→∞cx(n). We show that if x is a Sturmian word, then liminfn→∞cx(n)=2. We prove however that this is not a characterization of Sturmian words by exhibiting a restricted class of Toeplitz words, including the period-doubling word, which also verify this same condition on the limit infimum. In contrast we show that, for the Thue–Morse word t, liminfn→∞ct(n)=+∞.
Lingua originaleEnglish
pagine (da-a)36-56
Numero di pagine21
Stato di pubblicazionePublished - 2017

All Science Journal Classification (ASJC) codes

  • ???subjectarea.asjc.2600.2614???
  • ???subjectarea.asjc.2600.2607???
  • ???subjectarea.asjc.1700.1703???


Entra nei temi di ricerca di 'Cyclic complexity of words'. Insieme formano una fingerprint unica.

Cita questo