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Words avoiding 7/3-powers and the Thue-Morse morphism

Narad Rampersad
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Abstract

In 1982, Seebold showed that the only overlap-free binary words that are the fixed points of non-identity morphisms are the Thue-Morse word and its complement. We strengthen Seebold's result by showing that the same result holds if the term 'overlap-free' is replaced with '7/3-power-free'. Furthermore, the number 7/3 is best possible.

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Narad Rampersad. 2003-08-21. Words avoiding 7/3-powers and the Thue-Morse morphism. https://arxiv.org/abs/math/0307401

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