Abstract
This note answers a question of Kechris: if H < G is a normal subgroup of a countable group G, H has property MD and G/H is amenable and residually finite, then G also has property MD. Under the same hypothesis we prove that for any action a of G, if b is a free action of G/H, and b G is the induced action of G, then CInd G H (a|H) × b G weakly contains a. Moreover, if H < G is any subgroup of a countable group G, and the action of G on G/H is amenable, then CInd G H (a|H) weakly contains a whenever a is a Gaussian action.
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Bowen, L., Tucker-Drob, R.D. On a co-induction question of Kechris. Isr. J. Math. 194, 209–224 (2013). https://doi.org/10.1007/s11856-012-0071-7
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DOI: https://doi.org/10.1007/s11856-012-0071-7