On transcendence of numbers related to Sturmian and Arnoux-Rauzy words
We consider numbers of the form S_β(u): = ∑_{n=0}^∞ (u_n)/(βⁿ), where u = ⟨u_n⟩_{n=0}^∞ is an infinite word over a finite alphabet and β ∈ ℂ satisfies |β| > 1. Our main contribution is to present a combinatorial criterion on u, called echoing, that implies that S_β(u) is transcendental whenever β...
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Format: | Conference item |
Language: | English |
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Schloss Dagstuhl – Leibniz-Zentrum für Informatik
2024
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author | Kebis, P Luca, F Ouaknine, J Scoones, A Worrell, J |
author_facet | Kebis, P Luca, F Ouaknine, J Scoones, A Worrell, J |
author_sort | Kebis, P |
collection | OXFORD |
description | We consider numbers of the form S_β(u): = ∑_{n=0}^∞ (u_n)/(βⁿ), where u = ⟨u_n⟩_{n=0}^∞ is an infinite word over a finite alphabet and β ∈ ℂ satisfies |β| > 1. Our main contribution is to present a combinatorial criterion on u, called echoing, that implies that S_β(u) is transcendental whenever β is algebraic. We show that every Sturmian word is echoing, as is the Tribonacci word, a leading example of an Arnoux-Rauzy word. We furthermore characterise ̅{ℚ}-linear independence of sets of the form {1, S_β(u₁),…,S_β(u_k)}, where u₁,…,u_k are Sturmian words having the same slope. Finally, we give an application of the above linear independence criterion to the theory of dynamical systems, showing that for a contracted rotation on the unit circle with algebraic slope, its limit set is either finite or consists exclusively of transcendental elements other than its endpoints 0 and 1. This confirms a conjecture of Bugeaud, Kim, Laurent, and Nogueira. |
first_indexed | 2024-09-25T04:16:12Z |
format | Conference item |
id | oxford-uuid:e2fa381d-fc43-420a-885c-3f594e3301ba |
institution | University of Oxford |
language | English |
last_indexed | 2024-09-25T04:16:12Z |
publishDate | 2024 |
publisher | Schloss Dagstuhl – Leibniz-Zentrum für Informatik |
record_format | dspace |
spelling | oxford-uuid:e2fa381d-fc43-420a-885c-3f594e3301ba2024-07-16T10:35:29ZOn transcendence of numbers related to Sturmian and Arnoux-Rauzy wordsConference itemhttp://purl.org/coar/resource_type/c_5794uuid:e2fa381d-fc43-420a-885c-3f594e3301baEnglishSymplectic ElementsSchloss Dagstuhl – Leibniz-Zentrum für Informatik2024Kebis, PLuca, FOuaknine, JScoones, AWorrell, JWe consider numbers of the form S_β(u): = ∑_{n=0}^∞ (u_n)/(βⁿ), where u = ⟨u_n⟩_{n=0}^∞ is an infinite word over a finite alphabet and β ∈ ℂ satisfies |β| > 1. Our main contribution is to present a combinatorial criterion on u, called echoing, that implies that S_β(u) is transcendental whenever β is algebraic. We show that every Sturmian word is echoing, as is the Tribonacci word, a leading example of an Arnoux-Rauzy word. We furthermore characterise ̅{ℚ}-linear independence of sets of the form {1, S_β(u₁),…,S_β(u_k)}, where u₁,…,u_k are Sturmian words having the same slope. Finally, we give an application of the above linear independence criterion to the theory of dynamical systems, showing that for a contracted rotation on the unit circle with algebraic slope, its limit set is either finite or consists exclusively of transcendental elements other than its endpoints 0 and 1. This confirms a conjecture of Bugeaud, Kim, Laurent, and Nogueira. |
spellingShingle | Kebis, P Luca, F Ouaknine, J Scoones, A Worrell, J On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title | On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title_full | On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title_fullStr | On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title_full_unstemmed | On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title_short | On transcendence of numbers related to Sturmian and Arnoux-Rauzy words |
title_sort | on transcendence of numbers related to sturmian and arnoux rauzy words |
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