Abstract
The group Aff(ℚ) of affine transformations with rational coefficients acts naturally not only on the real line ℝ, but also on the p-adic fields ℚp. The aim of this note is to show that all these actions are necessary and sufficient to represent bounded μ-harmonic functions for a probability measure μ on Aff(ℚ) that is supported by a finitely generated subgroup, that is, to describe the Poisson boundary.
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Translated from Sovremennaya Matematika i Ee Prilozheniya (Contemporary Mathematics and Its Applications), Vol. 50, Functional Analysis, 2007.
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Brofferio, S. Poisson boundary for finitely generated groups of rational affinities. J Math Sci 156, 1–10 (2009). https://doi.org/10.1007/s10958-008-9253-6
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DOI: https://doi.org/10.1007/s10958-008-9253-6