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Related papers: Crossed Products and MF algebras

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We prove that the crossed product A x G of a separable, unital, quasidiagonal C*- algebra A by a discrete, countable, amenable, maximally almost periodic group G is quasidiagonal, provided that the action is almost periodic.

Operator Algebras · Mathematics 2013-01-22 Stefanos Orfanos

We study the matricial field (MF) property for certain reduced crossed product C*-algebras and their traces. Using classification techniques and induced K-theoretic dynamics, we show that reduced crossed products of ASH-algebras of real…

Operator Algebras · Mathematics 2016-06-29 Timothy Rainone , Christopher Schafhauser

Let F be a finite subgroup of SL_2 (Z) (necessarily isomorphic to one of Z/2Z, Z/3Z, Z/4Z, or Z/6Z), and let F act on the irrational rotational algebra A_{\theta} via the restriction of the canonical action of SL_2 (Z). Then the crossed…

Operator Algebras · Mathematics 2007-05-23 Siegfried Echterhoff , Wolfgang Lueck , N. Christopher Phillips , Samuel Walters

In the paper, we provide some examples of MF algebras by considering minimal or maximal tensor products of MF algebras and crossed products of MF algebras by finite groups or an integer group. We also present some examples of…

Operator Algebras · Mathematics 2008-11-18 Don Hadwin , Junhao Shen

For a twisted partial action \Theta of a group G on an (associative non-necessarily unital) algebra A over a commutative unital ring k, the crossed product A X_\Theta G is proved to be associative. Given a G-graded k-algebra B =…

Rings and Algebras · Mathematics 2010-03-16 M. Dokuchaev , R. Exel , J. J. Simon

In this paper, we consider the question whether a unital full free product of MF algebras with amalgamation over a finite dimensional C*-algebra is an MF algebra. First, we show that, under a natural condition, a unital full free product of…

Operator Algebras · Mathematics 2010-06-15 Qihui Li , Junhao Shen

For any central simple algebra over a field F which contains a maximal subfield M with non-trivial F-automorphism group G, G is solvable if and only if the algebra contains a finite chain of subalgebras which are generalized cyclic algebras…

Rings and Algebras · Mathematics 2021-04-13 Christian Brown , Susanne Pumpluen

We study the space of irreducible representations of a crossed product C*-algebra AxG, where G is a finite group. We construct a space $\Gamma$ which consists of pairs of irreducible representations of A and irreducible projective…

Operator Algebras · Mathematics 2012-08-13 Firuz Kamalov

Given a partial action \alpha of a group G on an associative algebra A we consider the crossed product A x_\alpha G. Using the algebras of multipliers of ideals of A we prove that A x_\alpha G is associative, provided that all ideals of A…

Rings and Algebras · Mathematics 2010-03-16 M. Dokuchaev , R. Exel

The recently developed theory of partial actions of discrete groups on $C^*$-algebras is extended. A related concept of actions of inverse semigroups on $C^*$-algebras is defined, including covariant representations and crossed products.…

funct-an · Mathematics 2008-02-03 Nandor Sieben

Suppose that $G$ has a representation group $H$, that $G_{ab}:= G/\bar{[G,G]}$ is compactly generated, and that $A$ is a \cs-algebra for which the complete regularization of $\Prim(A)$ is a locally compact Hausdorff space $X$. In a previous…

funct-an · Mathematics 2008-02-03 Siegfried Echterhoff , Dana P. Williams

We describe the structure of the irreducible representations of crossed products of unital C*-algebras by actions of finite groups in terms of irreducible representations of the C*-algebras on which the groups act. We then apply this…

Operator Algebras · Mathematics 2011-10-10 Alvaro Arias , Frederic Latremoliere

We investigate crossed products of Cuntz algebras by quasi-free actions of abelian groups. We prove that our algebras are AF-embeddable when actions satisfy a certain condition. We also give a necessary and sufficient condition that our…

Operator Algebras · Mathematics 2007-05-23 Takeshi Katsura

We show every isometric action is quasidiagonal in a strong sense. This shows that reduced crossed products by such actions are quasidiagonal or MF whenever the reduced algebra of the acting group is quasidiagonal or MF.

Operator Algebras · Mathematics 2022-03-01 Samantha Pilgrim

We consider a family of dynamical systems (A,alpha,L) in which alpha is an endomorphism of a C*-algebra A and L is a transfer operator for \alpha. We extend Exel's construction of a crossed product to cover non-unital algebras A, and show…

Operator Algebras · Mathematics 2015-05-13 Nathan Brownlowe , Iain Raeburn , Sean T. Vittadello

Let $\Gamma^+$ be the positive cone in a totally ordered abelian group $\Gamma$, and let $\alpha$ be an action of $\Gamma^+$ by endomorphisms of a $C^*$-algebra $A$. We consider a new kind of crossed-product $C^*$-algebra…

Operator Algebras · Mathematics 2007-05-23 Janny Lindiarni , Iain Raeburn

The paper presents a construction of the crossed product of a C*-algebra by a semigroup of endomorphisms generated by partial isometries.

Operator Algebras · Mathematics 2014-11-27 B. K. Kwasniewski , A. V. Lebedev

We introduce the notion of a crossed product of an algebra by a coalgebra $C$, which generalises the notion of a crossed product by a bialgebra well-studied in the theory of Hopf algebras. The result of such a crossed product is an algebra…

q-alg · Mathematics 2008-02-03 Tomasz Brzezinski

Let G be a group and let P be a subsemigroup of G. In order to describe the crossed product of a C*-algebra A by an action of P by unital endomorphisms we find that we must extend the action to the whole group G. This extension fits into a…

Operator Algebras · Mathematics 2010-03-16 Ruy Exel

For a free partial action of a group in a set we realize the associated partial skew group ring as an algebra of functions with finite support over an equivalence relation and we use this result to characterize the ideals in the partial…

Rings and Algebras · Mathematics 2013-06-18 Viviane M. Beuter , Daniel Gonçalves
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