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The natural extension of the random beta-transformation

Published online by Cambridge University Press:  04 November 2022

YOUNÈS TIERCE*
Affiliation:
Univ. Rouen Normandie, CNRS, LMRS, UMR 6085, F-76000 Rouen, France

Abstract

We construct a geometrico-symbolic version of the natural extension of the random $\beta $-transformation introduced by Dajani and Kraaikamp [Random $\beta $-expansions. Ergod. Th. & Dynam. Sys. 23(2) (2003) 461–479]. This construction provides a new proof of the existence of a unique absolutely continuous invariant probability measure for the random $\beta $-transformation, and an expression for its density. We then prove that this natural extension is a Bernoulli automorphism, generalizing to the random case the result of Smorodinsky [$\beta $-automorphisms are Bernoulli shifts. Acta Math. Acad. Sci. Hungar. 24 (1973), 273–278] about the greedy transformation.

Type
Original Article
Copyright
© The Author(s), 2022. Published by Cambridge University Press

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