New upper bounds for the q-numerical radii of 2×2 operator matrices

IF 2.1 2区数学 Q1 MATHEMATICS, APPLIED

Journal of Computational and Applied Mathematics Pub Date : 2025-03-06 DOI:10.1016/j.cam.2025.116618

Fuad Kittaneh , M.H.M. Rashid

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引用次数: 0

Abstract

This article introduces several enhanced bounds for the

q

-numerical radius concerning the sum and product of bounded linear operators in complex Hilbert spaces. Our findings represent a significant advancement over existing bounds in the current literature. Notably, the

q

-numerical radius inequalities for operator products and commutators are particular cases of our broader results. Furthermore, we derive new inequalities specifically targeting the

q

-numerical radii of

2 \times 2

operator matrices. These contributions not only refine the understanding of

q

-numerical radius bounds but also extend their applicability in operator theory. Through these improvements, we provide a more comprehensive framework that can be utilized to analyze and estimate the numerical radius in various contexts involving bounded linear operators.

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来源期刊

Journal of Computational and Applied Mathematics 数学-应用数学

CiteScore

5.40

自引率

4.20%

发文量

437

审稿时长

3.0 months

期刊介绍： The Journal of Computational and Applied Mathematics publishes original papers of high scientific value in all areas of computational and applied mathematics. The main interest of the Journal is in papers that describe and analyze new computational techniques for solving scientific or engineering problems. Also the improved analysis, including the effectiveness and applicability, of existing methods and algorithms is of importance. The computational efficiency (e.g. the convergence, stability, accuracy, ...) should be proved and illustrated by nontrivial numerical examples. Papers describing only variants of existing methods, without adding significant new computational properties are not of interest. The audience consists of: applied mathematicians, numerical analysts, computational scientists and engineers.