Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-28T14:22:03.030Z Has data issue: false hasContentIssue false

Maximal pattern complexity for Toeplitz words

Published online by Cambridge University Press:  10 July 2006

NERTILA GJINI
Affiliation:
University of New York, Tirana, Albania (e-mail: [email protected])
TETURO KAMAE
Affiliation:
Matsuyama University, 790-8578 Matsuyama, Japan (e-mail: [email protected])
TAN BO
Affiliation:
Department of Mathematics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China (e-mail: [email protected])
XUE YU-MEI
Affiliation:
Department of Mathematics, Tsinghua University, Beijing 100084, People's Republic of China (e-mail: [email protected])

Abstract

The notion of the maximal pattern complexity of words was introduced by Kamae and Zamboni. In this paper, we obtain an almost exact formula for the maximal pattern complexity $p^*_\alpha(k)$ of Toeplitz words $\alpha$ on an alphabet ${\mathbb A}$ defined by a sequence of coding words $(\eta^{(n)})^\infty\in({\mathbb A}\cup\{?\})^{\mathbb N}(n=1,2,\dotsc)$ including just one ‘?’ in their cycles $\eta^{(n)}$. Using this formula, we characterize pattern Sturmian words (i.e. $p^*_\alpha(k)=2k$ (for all $k$)) in this class. Moreover, we give a characterization of simple Toeplitz words in the sense of Kamae and Zamboni in terms of pattern complexity. In the case where $\eta^{(1)}=\eta^{(2)}=\dotsb$, we obtain the value $\lim_{k\to\infty}p_\alpha^*(k)/k$. We construct a Toeplitz word $\alpha\in{\mathbb A}^{\mathbb N}$ with $\#\A=2$ such that $p^*_\alpha(k)=2^k~(k=1,2,\dotsc)$, while Toeplitz words in our sense always have discrete spectra.

Type
Research Article
Copyright
2006 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.)