11,893 research outputs found
A cohomological characterisation of Yu's Property A for metric spaces
No full textWe introduce the notion of an asymptotically invariant mean as a coarse averaging operator for a metric space and show that the existence of such an operator is equivalent to Yu’s property A. As an application we obtain a positive answer to Higson’s question concerning the existence of a cohomological characterisation of property A. Specifically we provide coarse analogues of group cohomology and bounded cohomology (controlled cohomology and asymptotically invariant cohomology, respectively) for a metric space X, and provide a cohomological characterisation of property A which generalises the results of Johnson and Ringrose describing amenability in terms of bounded cohomology. These results amplify Guentner’s observation that property A should be viewed as coarse amenability for a metric space. We further provide a generalisation of Guentner’s result that box spaces of a finitely generated group have property A if and only if the group is amenable. This is used to derive Nowak’s theorem that the union of finite cubes of all dimensions does not have property A
Marriage record of Wright, George W. and Graham, Flora
No full textMarriage license for George W. Wright and Flora Graham. W.K. Piner was the officiant
W. M. Wright and Odie Graham Wearing Bonnets
No full textHead-and-shoulders portrait of W. M. Wright and Odie Graham (who is who is not identified) wearing bonnets
Replication Data for: The Political Implications of American Concerns about Economic Inequality
No full textReplication Data for: "The Political Implications of American Concerns about Economic Inequality," published in Political Behavio
A homological characterization of topological amenability
No full textGeneralizing Block and Weinberger’s characterization of amenability we introduce the notion of uniformly finite homology for a group action on a compact space and use it to give a homological characterization of topological amenability for actions. By considering the case of the natural action of G on its Stone-Cech compactification we obtain a homological characterisation of exactness of the group
Population ageing and immigration policy
No full textIn its simplest interpretation, population ageing is the increase in the average or median age of a population. It is the process by which there is a redistribution of relative population shares away from the younger to the older age groups
Amenable actions, invariant means and bounded cohomology
No full textWe show that topological amenability of an action of a countable discrete group on a compact spaceis equivalent to the existence of an invariant mean for the action. We prove also that this is equivalent to vanishing ofbounded cohomology for a class of Banach G-modules associated to the action, as well as to vanishing of a specific cohomology class. In the case when the compact space is a point our result reduces to a classic theorem of B.E.~Johnson characterising amenability of groups. In the case when the compactspace is the Stone-\v{C}ech compactification of the group we obtain a cohomological characterisation of exactness for the group, answering a question of Higson
Interview with Richard Wright and Graham Harwood of Mongrel
No full textThis interview features Richard Wright and Graham Harwood of Mongrel, a digital artist group known for working with marginalized communities. They talk about their creative process, including how they collaborate with groups like Irish Travelers and Congolese immigrants, and how those communities use digital technology in unique and meaningful ways
Pairings, duality, amenability and bounded cohomology
No full textWe give a new perspective on the homological characterisations of amenability given by Johnson and Ringrose in the context of bounded cohomology and by Block and Weinberger in the context of uniformly finite homology. We examine the interaction between their theories and explain the relationship between these characterisations. We apply these ideas to give a new proof of non- vanishing for the bounded cohomology of a free group
- …
