1,755 research outputs found
On coarse embeddability into -spaces and a conjecture of Dranishnikov
We show that the Hilbert space is coarsely embeddable into any for
. In particular, this yields new characterizations of
embeddability of separable metric spaces into the Hilbert space.Comment: 5 page
Controlled coarse homology and isoperimetric inequalities
We study a coarse homology theory with prescribed growth conditions. For a
finitely generated group G with the word length metric this homology theory
turns out to be related to amenability of G. We characterize vanishing of a
certain fundamental class in our homology in terms of an isoperimetric
inequality on G and show that on any group at most linear control is needed for
this class to vanish. The latter is a homological version of the classical
Burnside problem for infinite groups, with a positive solution. As applications
we characterize existence of primitives of the volume form with prescribed
growth and show that coarse homology classes obstruct weighted Poincare
inequalities.Comment: Final version, to appear in the Journal of Topolog
Aperiodic tilings of manifolds of intermediate growth
We give a homological construction of aperiodic tiles for certain open
Riemannian surfaces admitting actions of Grigorchuk groups of intermediate
growth.Comment: Accepted for publication in Groups, Geometry and Dynamic
Eilenberg swindles and higher large scale homology of products of trees
We show that uniformly finite homology of products of trees vanishes in
all degrees except degree , where it is infinite dimensional. Our method is
geometric and applies to several large scale homology theories, including
almost equivariant homology and controlled coarse homology. As an application
we determine group homology with -coefficients of lattices in
products of trees. We also show a characterization of amenability in terms of
1-homology and construct aperiodic tilings using higher homology.Comment: Final version, to appear in Groups, Geometry & Dynamic
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