Abstract
Let H 3(ℝ) be the 3-dimensional real Heisenberg group. Given a family of lattices Γ1 ⊃ Γ2 ⊃ … ⊂ H 3(ℝ), let T be the associated uniquely ergodic H 3(ℝ)-odometer, i.e., the inverse limit of the H 3(ℝ)-actions by rotations on the homogeneous spaces H 3(ℝ)/Γ j , j ∈ ℕ. We describe explicitly the decomposition of the underlying Koopman unitary representation of H 3(ℝ) into a countable direct sum of irreducible components and find the ergodic 2-fold self-joinings of T. We show that in general, the H 3(ℝ)-odometers are neither isospectral nor spectrally determined.
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The second named author was supported in part by Narodowe Centrum Nauki grant DEC-2011/03/B/ST1/00407.
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Danilenko, A.I., Lemańczyk, M. Odometer actions of the Heisenberg group. JAMA 128, 107–157 (2016). https://doi.org/10.1007/s11854-016-0003-2
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DOI: https://doi.org/10.1007/s11854-016-0003-2