General upper bounds for the numerical radius on complex Hilbert space

Author:

Al-Dolat Mohammed,Al-Zoubi Khaldoun

Abstract

In this work, we show that if {Ai}mi=1 and {Xi}mi=1  are two sets of bounded linear operators on the complex Hilbert space H, then for every n ∈ ℕ  and m > 2,  we have w(A1n–1 (Si=0 m–1 Am–i Xm–i A*i+1)(A*1)n–1) ≤ ||A1||2n–2 (2||A1|| ||Am|| + Sj=2m–1||Aj||2)w(E), and w(A1n–1A2X2(A*1)n ± A1nX1A*2(A*1)n–1) = 2||A1||2n–1 ||A2||w([0 X2 X1 0]), where w(.)  is the numerical radius and E = [0  Xm  .... X1 0].  This provides an improvement of Theorem 3 by Fong and Holbrook [3] and a generalization of Theorem 3 by Hirzallah et al. [6]. Moreover, we provide some new upper bounds for the numerical radius of off-diagonal operator matrices and provide a generalization of the main result by Abu-Omar and Kittaneh [17].

Publisher

Taru Publications

Subject

Applied Mathematics,Analysis

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. On the combinatorial identities using the nth power of square matrix;Journal of Interdisciplinary Mathematics;2024

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3