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In this paper, we give Poisson and Cauchy representation theorems in Hardy-Orlicz spaces on the upper complex half-plane. We use these theorems for the construction of dual spaces of certain Hardy-Orlicz spaces and also for the…

泛函分析 · 数学 2023-08-04 Jean-Marcel Tanoh Dje , Justin Feuto

We use results on inclusions of free products and extensions of completely positive maps to determine the maximal $C^*$-envelope for upper triangular $3 \times 3$ matrices. We consider these same results in the context of larger upper…

算子代数 · 数学 2023-08-14 Benton L. Duncan

Enveloping $C^*$-algebras for some finitely generated $*$-algebras are considered. It is shown that all of the considered algebras are identically defined by their dual spaces. The description in terms of matrix-functions is given. Keywords…

算子代数 · 数学 2011-01-27 Yurii Savchuk

We develop several upper and lower bounds for the $A$-Euclidean operator radius of $2$-tuple operators admitting $A$-adjoint, and show that they refine the earlier related bounds. As an application of the bounds developed here, we obtain…

泛函分析 · 数学 2024-08-14 Suvendu Jana , Pintu Bhunia , Kallol Paul

In this article, we prove an inner product inequality for Hilbert space operators. This inequality, then, is utilized to present a general numerical radius inequality using convex functions. Applications of the new results include obtaining…

泛函分析 · 数学 2022-07-19 Zahra Heydarbeygi , Mohammad Sababheh , Hamid Reza Moradi

We study singular integral operators with variable Calder\'on--Zygmund kernels and their commutators with $VMO$ functions in the framework of Orlicz spaces. After revisiting the classical $L^p$ theory, we establish boundedness results in…

偏微分方程分析 · 数学 2026-05-26 Amiran Gogatishvili , Pia Salerno , Lubomira Softova

In this paper, we generalize the notion of the $C$-numerical range of a matrix to operators in arbitrary tracial von Neumann algebras. For each self-adjoint operator $C$, the $C$-numerical range of such an operator is defined; it is a…

算子代数 · 数学 2019-02-08 Ken Dykema , Paul Skoufranis

In the first two sections of this paper we provide a brief account of the Cayley-Dickson algebras and prove that the radius on these algebras is given by the Euclidean norm. With this observation we resort to three related topics: a variant…

环与代数 · 数学 2015-05-08 Moshe Goldberg , Thomas J. Laffey

We give upper and lower bounds on the spectral radius of a graph in terms of the number of walks. We generalize a number of known results.

组合数学 · 数学 2007-05-23 Vladimir Nikiforov

In the context of studying $C^*$-algebras generated by Toeplitz operators acting on the poly-Bergman space $\mathcal{A}^2_{n}(\Pi)$ of the upper half-plane $\Pi$, we introduce a system of all-but-one orthogonal projections in generic…

In this paper, we introduce a new semi-norm of operators on a semi-Hilbertian space, which generalizes the A-numerical radius and A-operator semi-norm. We study the basic properties of this semi-norm, including upper and lower bounds for…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Anirban Sen , Kallol Paul

For $\mathbb B^n$ the unit ball of $\mathbb C^n$, we consider Bergman-Orlicz spaces of holomorphic functions in $L^\Phi_\alpha$, which are generalizations of classical Bergman spaces. We characterize the dual space of large Bergman-Orlicz…

经典分析与常微分方程 · 数学 2015-01-15 Benoit F. Sehba , Edgar Tchoundja

In this paper we discuss the structure of Orlicz spaces and weak Orlicz spaces on $\mathbb{R}^n$. We obtain some necessary and sufficient conditions for the inclusion property of these spaces. One of the keys is to compute the norm of the…

泛函分析 · 数学 2016-07-13 Al Azhary Masta , Hendra Gunawan , Wono Setya Budhi

In this paper, we present a captivating construction by Grothendieck, originally formulated for algebraic varieties, and adapt it to the realm of C*-algebras. Our main objective is to investigate the conditions under which this particular…

算子代数 · 数学 2023-07-31 E. Ghamari , C. Ingalls , D. Kucerovsky

The weighted numerical radius of a Hilbert space operator has been defined recently. This article explores other properties and uses this newly defined numerical radius to obtain several new interesting inequalities for the weighted…

泛函分析 · 数学 2022-04-19 Cristian Conde , Mohammad Sababheh , Hamid Reza Moradi

This paper establishes new upper bounds for the $A$-numerical radius of operator matrices in semi-Hilbertian spaces by leveraging the $A$-Buzano inequality and developing refined techniques for operator matrices. We present several sharp…

泛函分析 · 数学 2025-07-08 M. H. M. Rashid

A new C*-enlargement of a C*-algebra $A$ nested between the local multiplier algebra $M_{\text{loc}}(A)$ of $A$ and its injective envelope $I(A)$ is introduced. Various aspects of this maximal C*-algebra of quotients, $Q_{\text{max}}(A)$,…

算子代数 · 数学 2007-05-23 Pere Ara , Martin Mathieu

To minimize or upper-bound the value of a function "robustly", we might instead minimize or upper-bound the "epsilon-robust regularization", defined as the map from a point to the maximum value of the function within an epsilon-radius. This…

最优化与控制 · 数学 2010-06-10 Adrian S. Lewis , C. H. Jeffrey Pang

In this paper, we derive the sharp bounds of Toeplitz determinants for a class of holomorphic mappings on the bounded starlike circular domain $\Omega$ in $\mathbb{C}^n$, which extend certain known bounds for various subclasses of…

复变函数 · 数学 2022-11-29 Surya Giri , S. Sivaprasad Kumar

C-holomorphic functions defined on algebraic sets and having algebraic graphs can be considered as a complex counterpart of regulous functions introduced recently in real geometry. This note is a part of our study on the subject; we prove…

代数几何 · 数学 2020-05-12 Adam Białożyt , Maciej P. Denkowski , Piotr Tworzewski