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Related papers: Dilation Theory for Rank 2 Graph Algebras

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We take a new look at dilation theory for nonself-adjoint operator algebras. Among the extremal (co)extensions of a representation, there is a special property of being fully extremal. This allows a refinement of some of the classical…

Operator Algebras · Mathematics 2011-09-02 Kenneth R. Davidson , Elias G. Katsoulis

Let E be a product system of C*-correspondences over N^r. Some sufficient conditions for the existence of a not necessarily regular isometric dilation of a completely contractive representation of E are established and difference between…

Operator Algebras · Mathematics 2009-01-05 Adam Skalski

We develop a dilation theory for row contractions subject to constraints determined by sets of noncommutative polynomials. Under natural conditions on the constraints, we have uniqueness for the minimal dilation. A characteristic function…

Operator Algebras · Mathematics 2007-05-23 Gelu Popescu

Higher-rank graph generalisations of the Popescu-Poisson transform are constructed, allowing us to develop a dilation theory for higher rank operator tuples. These dilations are joint dilations of the families of operators satisfying…

Operator Algebras · Mathematics 2008-06-16 Adam Skalski , Joachim Zacharias

Motivated by the harmonic analysis of self-affine measures, we introduce a class of representations of the Cuntz algebra associated to random walks on graphs. The representations are constructed using the dilation theory of row…

Operator Algebras · Mathematics 2021-04-29 Dorin Ervin Dutkay , Nicholas Christoffersen

We apply Arveson's non-commutative boundary theory to dilate every Toeplitz-Cuntz-Krieger family of a directed graph $G$ to a full Cuntz-Krieger family for $G$. We do this by describing all representations of the Toeplitz algebra…

Operator Algebras · Mathematics 2018-05-30 Adam Dor-On , Guy Salomon

Dilation theory is a paradigm for studying operators by way of exhibiting an operator as a compression of another operator which is in some sense well behaved. For example, every contraction can be dilated to (i.e., is a compression of) a…

Operator Algebras · Mathematics 2020-02-18 Orr Shalit

We extended the definition of regular dilation to graph products of $\mathbb{N}$, which is an important class of quasi-lattice ordered semigroups. Two important results in dilation theory are unified under our result: namely, Brehmer's…

Operator Algebras · Mathematics 2017-02-21 Boyu Li

We introduce a notion called `maximal commuting piece' for tuples of Hilbert space operators. Given a commuting tuple of operators forming a row contraction there are two commonly used dilations in multivariable operator theory. Firstly…

Operator Algebras · Mathematics 2014-05-16 B. V. Rajarama Bhat , Tirthankar Bhattacharyya , Santanu Dey

We study dilations of finite tuples of normal, completely positive and completely contractive maps (which we call CP-maps) acting on a von Neumann algebra, and commuting according to a graph G. We show that if G is acyclic, then a tuple…

Operator Algebras · Mathematics 2021-08-16 Alexander Vernik

Given a contractive tuple of Hilbert space operators satisfying certain $A$-relations we show that there exists a unique minimal dilation to generators of Cuntz-Krieger algebras or its extension by compact operators. This Cuntz-Krieger…

Operator Algebras · Mathematics 2007-05-23 B. V. Rajarama Bhat , Santanu Dey , Joachim Zacharias

A contractive $n$-tuple $A=(A_1,...,A_n)$ has a minimal joint isometric dilation $S=(S_1,...,S_n)$ where the $S_i$'s are isometries with pairwise orthogonal ranges. This determines a representation of the Cuntz-Toeplitz algebra. When $A$…

Operator Algebras · Mathematics 2007-05-23 Kenneth R. Davidson , David W. Kribs , Miron E. Shpigel

We obtain dilation results which simultaneously generalize Sz.-Nagy dilation theorem for contractions, Ando's dilation theorem for commuting contractions, Sz.-Nagy--Foias commutant lifting theorem, and Schur's representation for the unit…

Functional Analysis · Mathematics 2017-01-12 Gelu Popescu

We begin a study of torsion theories for representations of an important class of associative algebras over a field which includes all finite W-algebras of type A, in particular the universal enveloping algebra of gl(n) (or sl(n)) for all…

Representation Theory · Mathematics 2010-03-12 Vyacheslav Futorny , Serge Ovsienko , Manuel Saorin

We study completely contractive representations of product systems $X$ of correspondences over the semigroup $\mathbb{Z}_+^k$. We present a necessary and sufficient condition for such a representation to have a regular isometric dilation.…

Operator Algebras · Mathematics 2007-05-23 Baruch Solel

Given a row contraction of operators on Hilbert space and a family of projections on the space which stabilize the operators, we show there is a unique minimal joint dilation to a row contraction of partial isometries which satisfy natural…

Functional Analysis · Mathematics 2007-05-23 Michael T. Jury , David W. Kribs

This paper examines actions of right LCM semigroups by endomorphisms of C*-algebras that encode an additional structure of the right LCM semigroup. We define contractive covariant representations for these semigroup dynamical systems and…

Operator Algebras · Mathematics 2021-10-19 Marcelo Laca , Boyu Li

Ando's theorem states that any pair of commuting contractions on a Hilbert space can be dilated to a pair of commuting unitaries. Parrott presented an example showing that an analogous result does not hold for a triple of pairwise commuting…

Operator Algebras · Mathematics 2007-05-23 David Opela

The notion of permutative representation is generalized to the $2$-adic ring $C^*$-algebra $\mathcal{Q}_{2}$. Permutative representations of $\mathcal{Q}_2$ are then investigated with a particular focus on the inclusion of the Cuntz algebra…

Operator Algebras · Mathematics 2019-07-12 Valeriano Aiello , Roberto Conti , Stefano Rossi

The Lie algebra su(2) of the classical group SU(2) is built from two commuting quon algebras for which the deformation parameter is a common root of unity. This construction leads to (i) a not very well-known polar decomposition of the…

Quantum Physics · Physics 2007-05-23 M. R. Kibler
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