Two-block substitutions and morphic words

Advances in Applied Mathematics, vol. 148, pp. 102536

Abstract

We consider in general two-block substitutions and their fixed points. We prove that some of them have a simple structure: their fixed points are morphic sequences. Others are intrinsically more complex, such as the Kolakoski sequence. We prove this for the Thue-Morse sequence in base 3/2.

Authors 2

1. Michel Dekking corresponding

   Delft University of Technology · Centrum Wiskunde & Informatica

   Affiliation as printed

   3TU Applied Mathematics Institute and Delft University of Technology, Faculty EWI, P.O. Box 5031, 2600 GA Delft, the Netherlands

   CWI, Amsterdam, the Netherlands

2. Michael P. Keane Aachen Mathematical Institute

   Leiden University · Delft University of Technology

   Affiliation as printed

   3TU Applied Mathematics Institute and Delft University of Technology, Faculty EWI, the Netherlands

   Mathematical Institute, University of Leiden, Niels Bohrweg 1, 2333 CA Leiden, the Netherlands