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Related papers: Classification of sub-Cuntz states

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We consider bipartite exact entanglement embezzlement with a catalyst state vector $\psi$ in a Hilbert space $\mathcal{H}$ using unitaries (or more generally, contractions). If $\mathcal{M} \subseteq \mathcal{B}(\mathcal{H})$ is a von…

Operator Algebras · Mathematics 2026-05-22 Samuel J. Harris

In a number of recent papers, the idea of generalized boundaries has found use in fractal and in multiresolution analysis; many of the papers having a focus on specific examples. Parallel with this new insight, and motivated by quantum…

Functional Analysis · Mathematics 2018-05-17 Palle Jorgensen , Feng Tian

We show a correspondence between simple continued fraction expansions of irrational numbers and irreducible permutative representations of the Cuntz algebra ${\cal O}_{\infty}$. With respect to the correspondence, it is shown that the…

Operator Algebras · Mathematics 2009-01-16 Katsunori Kawamura , Yoshiki Hayashi , Dan Lascu

We study topological aspects of the category of abstract Cuntz semigroups, termed Cu. We provide a suitable setting in which we are able to uniformly control how to approach an element of a Cu-semigroup by a rapidly increasing sequence.…

Operator Algebras · Mathematics 2022-06-17 Laurent Cantier

In this paper, we extend Ocneanu's theory of connections on graphs to define a 2-category whose 0-cells are tracial Bratteli diagrams, and whose 1-cells are generalizations of unitary connections. We show that this 2-category admits an…

Quantum Algebra · Mathematics 2022-11-10 Paramita Das , Mainak Ghosh , Shamindra Ghosh , Corey Jones

We introduce a new invariant for C*-algebras of stable rank one that merges the Cuntz semigroup information together with the K$_1$-group information. This semigroup, termed the Cu$_1$-semigroup, is constructed as equivalence classes of…

Operator Algebras · Mathematics 2021-07-07 Laurent Cantier

The Cuntz algebra O_n is presented as a partial crossed product in which an amenable group partially acts on an abelian C*-algebra. The partial action is related to the Cuntz groupoid for O_n and connections are made with non-self-adjoint…

Operator Algebras · Mathematics 2007-05-23 Alan Hopenwasser

When two or more subsystems of a quantum system interact with each other they can become entangled. In this case the individual subsystems can no longer be described as pure quantum states. For systems with only 2 subsystems this…

Quantum Physics · Physics 2007-05-23 Rachel Parker , Chris Doran

We examine the ranks of operators in semi-finite C*-algebras as measured by their densely defined lower semicontinuous traces. We first prove that a unital simple C*-algebra whose extreme tracial boundary is nonempty and finite contains…

Operator Algebras · Mathematics 2015-06-01 Aaron Tikuisis , Andrew Toms

We prove a new kind of quantum de Finetti theorem for representations of the unitary group U(d). Consider a pure state that lies in the irreducible representation U_{mu+nu} for Young diagrams mu and nu. U_{mu+nu} is contained in the tensor…

Quantum Physics · Physics 2009-11-13 Matthias Christandl , Robert Koenig , Graeme Mitchison , Renato Renner

Tensor models are generalizations of matrix models, and are studied as discrete models of quantum gravity for arbitrary dimensions. Among them, the canonical tensor model (CTM for short) is a rank-three tensor model formulated as a totally…

High Energy Physics - Theory · Physics 2015-12-23 Gaurav Narain , Naoki Sasakura

We investigate subalgebras $A$ of the Cuntz algebra ${\mathcal O}_n$ that arise as finite direct sums of corners of the UHF-subalgebra ${\mathcal F}_n$. For such an $A$, we completely determine its normalizer group inside ${\mathcal O}_n$.

Operator Algebras · Mathematics 2015-01-20 Tomohiro Hayashi , Wojciech Szymanski

We study the Cuntz semigroup for non-simple $\text{C}^*$-algebras in this paper. In particular, we use the extended Elliott invariant to characterize the Cuntz comparison for $\text{C}^*$-algebras with the projection property which have…

Operator Algebras · Mathematics 2017-09-15 George Elliott , Kun Wang

We establish a crossed product decomposition theorem for stabilized Cuntz--Pimsner algebras. This result extends Cuntz's classical decomposition for the Cuntz algebras $\mathcal{O}_n$ and reveals an implicit symmetric structure within…

Operator Algebras · Mathematics 2026-05-21 Miho Mukohara , Yuhei Suzuki

We find the complete branching law for the restriction of certain unitary representations of $O(1,n+1)$ to the subgroups $O(1,m+1)\times O(n-m)$, $0\leq m\leq n$. The unitary representations we consider belong either to the unitary…

Representation Theory · Mathematics 2017-03-21 Jan Möllers , Yoshiki Oshima

A generalization of the canonical coherent states of a quantum harmonic oscillator has been performed by requiring the conditions of normalizability, continuity in the label and resolution of the identity operator with a positive weight…

Quantum Physics · Physics 2023-03-28 Filippo Giraldi , Francesco Mainardi

We study the properties of {\bf exact} (all level $k$) quantum coherent states in the context of string theory on a group manifold (WZWN models). Coherent states of WZWN models may help to solve the unitarity problem: Having positive norm,…

High Energy Physics - Theory · Physics 2016-08-16 A. L. Larsen , N. Sánchez

States which minimize the Schr\"odinger--Robertson uncertainty relation are constructed as eigenstates of an operator which is a element of the $h(1) \oplus \su(2)$ algebra. The relations with supercoherent and supersqueezed states of the…

Mathematical Physics · Physics 2007-05-23 Nibaldo Alvarez-Moraga , Veronique Hussin

Given an arbitrary infinite 0--1 matrix A having no identically zero rows, we define an algebra OA as the universal C*-algebra generated by partial isometries subject to conditions that generalize, to the infinite case, those introduced by…

funct-an · Mathematics 2007-05-23 Ruy Exel , Marcelo Laca

We develop new techniques for the construction and classification of representations of row-finite and locally convex higher-rank graph C*-algebras O. This class includes Cuntz--Krieger algebras associated to row-finite directed graphs. Our…

Operator Algebras · Mathematics 2026-04-20 Arnaud Brothier , Aidan Sims , Dilshan Wijesena