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Higher Kazhdan projections and delocalised $\ell^ 2$-Betti numbers
Published 6 May 2024 in math.OA, math.GR, and math.KT | (2405.03837v1)
Abstract: We provide an explicit description of the K-classes of higher Kazhdan projections in degrees greater than 0 for specific free product groups and Cartesian product groups. Employing this description, we obtain new calculations of Lott's delocalised $\ell2$-Betti numbers. Notably, we establish the first non-vanishing results for infinite groups.
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