Zobrazeno 1 - 10
of 219
pro vyhledávání: '"Exel, Ruy"'
For a uniformly locally finite metric space $(X, d)$, we investigate \emph{coarse} flows on its uniform Roe algebra $\mathrm{C}^*_u(X)$, defined as one-parameter groups of automorphisms whose differentiable elements include all partial isometries ari
Externí odkaz:
http://arxiv.org/abs/2411.06999
Autor:
Braga, Bruno de Mendonça, Exel, Ruy
We initiate the treatment of KMS states on uniform Roe algebras $\mathrm{C}^*_u(X)$ for a class of naturally occurring flows on these algebras. We show that KMS states on $\mathrm{C}^*_u(X)$ always factor through the diagonal operators $\ell_\infty(X
Externí odkaz:
http://arxiv.org/abs/2304.05873
Autor:
Exel, Ruy
The goal of this short note is to prove that when $A$ is a closed *-subalgebra of a C*-algebra $B$ satisfying the ideal intersection property plus a mild axiom (INV), then the map $J\mapsto J\cap A$ establishes an isomorphism from the boolean algebra
Externí odkaz:
http://arxiv.org/abs/2301.10073
Autor:
Exel, Ruy
We characterize exotic C*-algebras of twisted, principal \'etale groupoids, together with the abelian subalgebra associated to the unit space, as precisely being the inclusions "$A\subseteq B$" of C*-algebras in which $A$ is abelian, regular, and sat
Externí odkaz:
http://arxiv.org/abs/2110.09445
Let $\Gamma$ be a discrete group acting freely via homeomorphisms on the compact Hausdorff space $X$ and let $C(X) \rtimes_\eta \Gamma$ be the completion of the convolution algebra $C_c(\Gamma,C(X))$ with respect to a $C^*$-norm $\eta$. A non-zero id
Externí odkaz:
http://arxiv.org/abs/2109.06293
Let $A$ be a C$^*$-algebra and let $D$ be a Cartan subalgebra of $A$. We study the following question: if $B$ is a C$^*$-algebra such that $D \subseteq B \subseteq A$, is $D$ a Cartan subalgebra of $B$? We give a positive answer in two cases: the cas
Externí odkaz:
http://arxiv.org/abs/1912.03686
Autor:
Exel, Ruy
We discuss the relationship between tight and cover-to-join representations of semilattices and inverse semigroups, showing that a slight extension of the former, together with an appropriate selection of co-domains, makes the two notions equivalent.
Externí odkaz:
http://arxiv.org/abs/1903.02911
Given a 0-1 infinite matrix $A$ and its countable Markov shift $\Sigma_A$, one of the authors and M. Laca have introduced a kind of {\it generalized countable Markov shift} $X_A=\Sigma_A \cup Y_A$, where $Y_A$ is a special set of finite admissible wo
Externí odkaz:
http://arxiv.org/abs/1808.00765