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Lamplighter groups, median spaces and Hilbertian geometry

Part of: Special aspects of infinite or finite groups

Published online by Cambridge University Press:  09 June 2022

Anthony Genevois
Anthony Genevois*
Affiliation:
Institut Montpellierain Alexander Grothendieck, 499-554 Rue du Truel, 34090 Montpellier, France (anthony.genevois@umontpellier.fr)
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Abstract

From any two median spaces $X$ and $Y$, we construct a new median space $X \circledast Y$, referred to as the diadem product of $X$ and $Y$, and we show that this construction is compatible with wreath products in the following sense: given two finitely generated groups $G,\,H$ and two (equivariant) coarse embeddings into median spaces $X,\,Y$, there exist a(n equivariant) coarse embedding $G\wr H \to X \circledast Y$. The construction offers a unified point of view on various questions related to the Hilbertian geometry of wreath products of groups.

Keywords

Wreath productsmedian spacesCAT(0) cube complexescompressionHaagerup propertyKazhdan property (T)

MSC classification

Primary: 20F65: Geometric group theory
Secondary: 20F67: Hyperbolic groups and nonpositively curved groups
Type
Research Article
Information
Proceedings of the Edinburgh Mathematical Society , Volume 65 , Issue 2 , May 2022 , pp. 500 - 529
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Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on Behalf of The Edinburgh Mathematical Society

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