A1 Refereed original research article in a scientific journal

EXISTENCE OF AN INFINITE TERNARY 64-ABELIAN SQUARE-FREE WORD




AuthorsMari Huova

PublisherEDP SCIENCES S A

Publication year2014

JournalRAIRO: Informatique Théorique et Applications / RAIRO: Theoretical Informatics and Applications

Journal name in sourceRAIRO-THEORETICAL INFORMATICS AND APPLICATIONS

Journal acronymRAIRO-THEOR INF APPL

Volume48

Issue3

First page 307

Last page314

Number of pages8

ISSN0988-3754

DOIhttps://doi.org/10.1051/ita/2014012


Abstract

We consider a recently defined notion of k-abelian equivalence of words by concentrating on avoidance problems. The equivalence class of a word depends on the numbers of occurrences of different factors of length k for a fixed natural number k and the prefix of the word. We have shown earlier that over a ternary alphabet k-abelian squares cannot be avoided in pure morphic words for any natural number k. Nevertheless, computational experiments support the conjecture that even 3-abelian squares can be avoided over ternary alphabets. In this paper we establish the first avoidance result showing that by choosing k to be large enough we have an infinite k-abelian square-free word over three letter alphabet. In addition, this word can be obtained as a morphic image of a pure morphic word.




Last updated on 2024-26-11 at 16:46