Groups with the Haagerup Property
A locally compact group has the Haagerup property, or is a-T-menable in the sense of Gromov, if it admits a proper isometric action on some affine Hilbert space. As Gromov''s pun is trying to indicate, this definition is designed as a strong negation to Kazhdan''s property (T), characterized by the fact that every isometric action on some affine Hilbert space has a fixed point.
The aim of this book...
A locally compact group has the Haagerup property, or is a-T-menable in the sense of Gromov, if it admits a proper isometric action on some affine Hilbert space. As Gromov''s pun is trying to indicate, this definition is designed as a strong negation to Kazhdan''s property (T), characterized by the fact that every isometric action on some affine Hilbert space has a fixed point.
The aim of this book...
