85,917 research outputs found
A Characterization of BLD-Mappings Between Metric Spaces
We prove a characterization theorem for BLD-mappings between complete locally compact path-metric spaces. As a corollary, we obtain a sharp limit theorem for BLD-mappings.Peer reviewe
On Path Integral Localization and the Laplacian
We introduce a new localization principle which is a generalized canonical
transformation. It unifies BRST localization, the non-abelian localization
principle and a special case of the conformal Duistermaat-Heckman integration
formula of Paniak, Semenoff and Szabo. The heat kernel on compact Lie groups is
localized in two ways. First using a non-abelian generalization of the
derivative expansion localization of Palo and Niemi and secondly using the BRST
localization principle and a configuration space path integral. In addition we
present some new formulas on homogeneous spaces which might be useful in a
possible localization of Selberg's trace formula on locally homogeneous spaces.Comment: 30 pages LaTeX, 1 figure; published versio
Topological Full Groups of Ample Groupoids with Applications to Graph Algebras
We study the topological full group of ample groupoids over locally compact
spaces. We extend Matui's definition of the topological full group from the
compact, to the locally compact case. We provide two general classes of
groupoids for which the topological full group, as an abstract group, is a
complete isomorphism invariant. Hereby extending Matui's Isomorphism Theorem.
As an application, we study graph groupoids and their topological full groups,
and obtain sharper results for this class. The machinery developed in this
process is used to prove an embedding theorem for ample groupoids, akin to
Kirchberg's Embedding Theorem for -algebras. Consequences for graph
-algebras and Leavitt path algebras are also spelled out. In particular,
we improve on a recent embedding theorem of Brownlowe and S{\o}rensen for
Leavitt path algebras.Comment: 58 pages. V4: Deleted an obsolete reference. Updated Journal
reference. Minor typographical changes. (V3: Rewritten the "Our results" and
"Pr\'ecis" part of the Introduction. Added Remark 6.20 and Definition 7.8.
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