Universidade Federal de Santa Catarina

output

19952026

most citedOptimized delta expansion for relativistic nuclear models

651 citations

researchers with a paper here

Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.

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53 papers · 1 filter

math.OA2025

Bilinear maps having Jordan product property

Jorge J. Garcés, Mykola Khrypchenko

We study symmetric continuous bilinear maps $V$ on a C $^{*}$ -algebra $A$ that have the Jordan product property at a fixed element $z \in A$ . We show that, whenever $A$ is a finite dir…

math.OA2024

Deformation of Fell bundles

Alcides Buss, Siegfried Echterhoff

In this paper we study deformations of $C^{*}$ -algebras that are given as cross-sectional $C^{*}$ -algebras of Fell bundles over locally compact groups $G$ . Our deformation comes from a…

math.OA2022★ 2 cited

Étale categories, restriction semigroups, and their operator algebras

Natã Machado, Gilles G. de Castro

We define the full and reduced non-self-adjoint operator algebras associated with étale categories and restriction semigroups, answering a question posed by Kudryavtseva and Lawson…

math.OA2021

$$ -Lie-type maps on $C^{}$ -algebras

Ruth Nascimento Ferreira, Bruno Leonardo Macedo Ferreira, Henrique Guzzo Junior +1

Let $A$ and $A^{'}$ be two $C^{*}$ -algebras with identities $I_{A}$ and $I_{A^{'}}$ , respectively, and $P_{1}$ and $P_{2} = I_{A} - P_{1}$ …

math.OA2020

$$ -Jordan-type maps on $C^{}$ -algebras

Bruno Leonardo Macedo Ferreira, Bruno Tadeu Costa

Let $A$ and $A^{'}$ be two $C^{*}$ -algebras with identities $I_{A}$ and $I_{A^{'}}$ , respectively, and $P_{1}$ and $P_{2} = I_{A} - P_{1}$ …

math.OA2019★ 10 cited

Amenability and approximation properties for partial actions and Fell bundles

Fernando Abadie, Alcides Buss, Damián Ferraro

Building on previous papers by Anantharaman-Delaroche (AD) we introduce and study the notion of AD-amenability for partial actions and Fell bundles over discrete groups. We prove t…

math.OA2019★ 4 cited

Characterizing groupoid C*-algebras of non-Hausdorff étale groupoids

R. Exel, D. Pitts

Given a not-necessarily Hausdorff, topologically free, twisted étale groupoid $(G, L)$ , we consider its "essential groupoid C*-algebra", denoted $C_{ess}^{*} (G, L)$ , obtained by comp…

math.OA2018★ 13 cited

Homology of odometers

Eduardo Scarparo

We compute the homology groups of transformation groupoids associated with odometers and show that certain infinite dihedral group odometers give rise to counterexamples to the HK…

math.OA2018★ 2 cited

Quasi-invariant measures for generalized approximately proper equivalence relations

R. Bissacot, R. Exel, R. Frausino +1

We introduce a generalization of the notion of approximately proper equivalence relations studied by Renault and with it we build an étale groupoid. Choosing a suitable set of cont…

math.OA2018★ 2 cited

The maximal injective crossed product

Alcides Buss, Siegfried Echterhoff, Rufus Willett

A crossed product functor is said to be injective if it takes injective morphisms to injective morphisms. In this paper we show that every locally compact group $G$ admits a maxima…

math.OA2018

The orbit spaces of groupoids whose $C^{*}$ -algebras are CCR

Daniel W van Wyk

Let G be second countable locally compact Hausdorff groupoid with a continuous Haar system. We remove the assumption of amenability in a theorem of Clark about groupoids whose $C^*…

math.OA2018★ 11 cited

$C^{*}$ -algebras of self-similar graphs over arbitrary graphs

Ruy Exel, Enrique Pardo, Charles Starling

In this note we extend the construction of a $C^{*}$ -algebra associated to a self-similar graph to the case of arbitrary countable graphs. We reduce the problem to the row-finite cas…

math.OA2018★ 8 cited

$C^{*}$ -simplicity and representations of topological full groups of groupoids

Kevin Aguyar Brix, Eduardo Scarparo

Given an ample groupoid $G$ with compact unit space, we study the canonical representation of the topological full group $[[G]]$ in the full groupoid $C^{*}$ -algebra $C^{*} (G)$ . In par…

math.OA2017★ 6 cited

Morita enveloping Fell bundles

Fernando Abadie, Alcides Buss, Damián Ferraro

We introduce notions of weak and strong equivalence for non-saturated Fell bundles over locally compact groups and show that every Fell bundle is strongly (resp. weakly) equivalent…

math.OA2017★ 4 cited

KMS and ground states on ultragraph C*-algebras

Gilles Gonçalves de Castro, Daniel Gonçalves

We describe KMS and ground states arising from a generalized gauge action on ultragraph C*-algebras. We focus on ultragraphs that satisfy Condition~(RFUM), so that we can use the p…

math.OA2017★ 3 cited

On the $C^{*}$ -algebra generated by the Koopman representation of a topological full group

Eduardo Scarparo

Let $(X, T, μ)$ be a Cantor minimal sytem and $[[T]]$ the associated topological full group. We analyze $C_{π}^{*} ([[T]])$ , where $π$ is the Koopman representation attached to the action…

math.OA2016★ 7 cited

A universal property for groupoid C*-algebras. I

Alcides Buss, Rohit Holkar, Ralf Meyer

We describe representations of groupoid C*-algebras on Hilbert modules over arbitrary C*-algebras by a universal property. For Hilbert space representations, our universal property…

math.OA2016

The ideal structure of algebraic partial crossed products

M. Dokuchaev, R. Exel

Given a partial action of a discrete group $G$ on a Hausdorff, locally compact, totally disconnected topological space $X$ , we consider the correponding partial action of $G$ on th…

math.OA2016★ 1 cited

Branching Systems and General Cuntz-Krieger Uniqueness Theorem for Ultragraph C*-algebras

Daniel Gonçalves, Hui Li, Danilo Royer

We give a notion of branching systems on ultragraphs. From this we build concrete representations of ultragraph C*-algebras on the bounded linear operators of Hilbert spaces. To ea…

math.OA2015★ 12 cited

Reduced C*-algebras of Fell bundles over inverse semigroups

Alcides Buss, Ruy Exel, Ralf Meyer

We construct a weak conditional expectation from the section C*-algebra of a Fell bundle over a unital inverse semigroup to its unit fibre. We use this to define the reduced C*-alg…

math.OA2015

Exotic Crossed Products

Alcides Buss, Siegfried Echterhoff, Rufus Willett

An exotic crossed product is a way of associating a C*-algebra to each C*-dynamical system that generalizes the well-known universal and reduced crossed products. Exotic crossed pr…

math.OA2014★ 7 cited

Faithful representations of graph algebras via branching systems

Daniel Gonçalves, Hui Li, Danilo Royer

We continue to investigate branching systems of directed graphs and their connections with graph algebras. We give a sufficient condition under which the representation induced fro…

math.OA2014★ 6 cited

Amenable actions of inverse semigroups

Ruy Exel, Charles Starling

We say that an action of a countable discrete inverse semigroup on a locally compact Hausdorff space is amenable if its groupoid of germs is amenable in the sense of Anantharaman-D…

math.OA2013★ 4 cited

K-theory of crossed products of tiling C*-algebras by rotation groups

Charles Starling

Let $Ω$ be a tiling space and let $G$ be the maximal group of rotations which fixes $Ω$ . Then the cohomology of $Ω$ and $Ω/ G$ are both invariants which give useful geometric inform…