Action dimension and L^2 Cohomology

Duration: 52 mins 56 secs
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Description: Schreve, K
Friday 23rd June 2017 - 10:00 to 11:00
 
Created: 2017-07-19 16:20
Collection: Non-Positive Curvature Group Actions and Cohomology
Publisher: Isaac Newton Institute
Copyright: Schreve, K
Language: eng (English)
Distribution: World     (downloadable)
Explicit content: No
Aspect Ratio: 16:9
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: Co-authors: Michael Davis (Ohio State University), Giang Le ()

The action dimension of a group G is the minimal dimension of contractible manifold that G acts on properly discontinuously. Conjecturally, if a group has nontrivial cohomology in dimension n, the action dimension of G is bounded below by 2n. I will describe examples where this conjecture holds, including lattices in Euclidean buildings, graph products, and fundamental groups of some complex hyperplane complements. This will involve joint work with Mike Davis and Giang Le, as well as Grigori Avramidi, Mike Davis, and Boris Okun.
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