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Related papers: Monotone operator functions on $C^*$-algebra

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We present some general theorems about operator algebras that are algebras of functions on sets, including theories of local algebras, residually finite dimensional operator algebras and algebras that can be represented as the scalar…

Operator Algebras · Mathematics 2009-07-30 Meghna Mittal , Vern Paulsen

Let $\gamma = (\gamma_1,...,\gamma_N)$, $N \geq 2$, be a system of proper contractions on a complete metric space. Then there exists a unique self-similar non-empty compact subset $K$. We consider the union ${\mathcal G} = \cup_{i=1}^N…

Operator Algebras · Mathematics 2007-05-23 Tsuyoshi Kajiwara , Yasuo Watatani

This paper studies Rota-Baxter operators on the matrix $C^*$-algebra $M_n(\mathbb{C})$, motivated by the discrete Toeplitz algebra (whose role is purely heuristic; see Remark~\ref{rem:toeplitz_scope}). We provide a structural classification…

Rings and Algebras · Mathematics 2026-05-12 Marwa Ennaceur

In this article we give a short and informal overview of some aspects of the theory of C*- and von Neumann algebras. We also mention some classical results and applications of these families of operator algebras.

Operator Algebras · Mathematics 2013-04-12 Fernando Lledó

We survey the model theory of operator systems and C$^*$-algebras.

Operator Algebras · Mathematics 2022-10-11 Thomas Sinclair

In this paper it is shown that the lattice of C*-covers of an operator algebra does not contain enough information to distinguish operator algebras up to completely isometric isomorphism. In addition, four natural equivalences of the…

Operator Algebras · Mathematics 2025-01-16 Adam Humeniuk , Christopher Ramsey

Analogues for Hilbert C*-modules of classical results of Fourier series theory in Hilbert spaces are considered. Relations between different properties of orthogonal and orthonormal systems for Hilbert C*-modules are studied with special…

Operator Algebras · Mathematics 2009-06-05 Giovanni Landi , Alexander Pavlov

We introduce a classification of locally compact Hausdorff topological spaces with respect to the behavior of $\sigma$-compact subsets, and relying on this classification we study properties of corresponding $C^*$-algebras in terms of frame…

Operator Algebras · Mathematics 2022-06-22 Denis Fufaev

We investigate relations on elements in C*-algebras, including *-polynomial relations, order relations and all relations that correspond to universal C*-algebras. We call these C*-relations and define them axiomatically. Within these are…

Operator Algebras · Mathematics 2010-12-30 Terry A. Loring

In recent work of the second author, a technical result was proved establishing a bijective correspondence between certain open projections in a C*-algebra containing an operator algebra A, and certain one-sided ideals of A. Here we give…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Damon M. Hay , Matthew Neal

We study the general and connected stable ranks for C*-algebras. We estimate these ranks for pullbacks of C*-algebras, and for tensor products by commutative C*-algebras. Finally, we apply these results to determine these ranks for certain…

Operator Algebras · Mathematics 2018-06-26 Prahlad Vaidyanathan

This paper addresses the isomorphism problem for the universal (nonself-adjoint) operator algebras generated by a row contraction subject to homogeneous polynomial relations. We find that two such algebras are isometrically isomorphic if…

Operator Algebras · Mathematics 2011-07-15 Kenneth R. Davidson , Christopher Ramsey , Orr Shalit

We consider the question of when the multiplier algebra $M(\mathcal{A})$ of a $C^*$-algebra $\mathcal{A}$ is a $ W^*$-algebra, and show that it holds for a stable $C^*$-algebra exactly when it is a $C^*$-algebra of compact operators. This…

Operator Algebras · Mathematics 2013-04-30 Charles A. Akemann , Massoud Amini , Mohammad B. Asadi

We investigate monotone operator functions of several variables under a trace or a trace-like functional. In particular, we prove the inequality \tau(x_1... x_n)\le\tau(y_1... y_n) for a trace \tau on a C^*-algebra and abelian n-tuples…

Operator Algebras · Mathematics 2007-05-23 Frank Hansen

In this paper we study some fundamental algebraic properties of slice functions and slice regular functions over an alternative $^*$-algebra $A$ over $\mathbb{R}$. These recently introduced function theories generalize to higher dimensions…

Complex Variables · Mathematics 2017-11-20 Riccardo Ghiloni , Alessandro Perotti , Caterina Stoppato

From a planar algebra, we give a functorial construction to produce numerous associated $C^*$-algebras. Our main construction is a Hilbert $C^*$-bimodule with a canonical real subspace which produces Pimsner-Toeplitz, Cuntz-Pimsner, and…

Operator Algebras · Mathematics 2014-01-14 Michael Hartglass , David Penneys

We study C*-algebras generated by two partitions of unity with orthogonality relations governed by hypercubes $Q_n$ for $n \in \mathbb{N} \setminus \{0\}$. These "hypercube C*-algebras'' are special cases of bipartite graph C*-algebras…

Operator Algebras · Mathematics 2025-10-20 Björn Schäfer

In this paper, we investigate certain submodules in C*-algebras associated to effective \'etale groupoids. First, we show that a submodule generated by normalizers is a closure of the set of compactly supported continuous functions on some…

Operator Algebras · Mathematics 2024-04-12 Fuyuta Komura

In this paper, we introduce and study a new class of bounded linear operators on complex Hilbert spaces, which we call 2-C-normal operators. This class is inspired by and closely related to the notion of 2-normal operators, with additional…

Functional Analysis · Mathematics 2025-10-09 Messaoud Guesba , Ismail Lakehal , Sid Ahmed Ould Ahmed Mahmoud

This paper concerns three classes of real-valued functions on intervals, operator monotone functions, operator convex functions, and strongly operator convex functions. Strongly operator convex functions were previously treated in [3] and…

Functional Analysis · Mathematics 2018-05-29 Lawrence G. Brown , Mitsuru Uchiyama