New Estimates on Numerical Radius and Operator Norm of Hilbert Space Operators

被引：12

作者：

Hassani, Mahmoud ^{[1
]}

Omidvar, Mohsen Erfanian ^{[1
]}

Moradi, Hamid Reza ^{[1
]}

机构：

[1] Islamic Azad Univ, Dept Math, Mashhad Branch, Mashhad, Razavi Khorasan, Iran

来源：

TOKYO JOURNAL OF MATHEMATICS | 2021年 / 44卷 / 02期

关键词：

Numerical radius; operator norm; operator convex function; Hermite-Hadamard inequality; INEQUALITIES;

D O I：

10.3836/tjm/1502179337

中图分类号：

O1 [数学];

学科分类号：

0701 ; 070101 ;

摘要：

The main goal of this article is to present a new approach, made up of integrals, to refine some numerical radius inequalities. Let A be a bounded linear operator on a complex Hilbert space. If 1 <= r <= 2, it is shown that omega(2r) (A) <= parallel to integral(1)(0) ((1-t) (vertical bar A vertical bar(2) + vertical bar A*vertical bar(2)/2) + t omega (A(2))I)(r) dt parallel to. Here omega (.),parallel to.parallel to are the numerical radius and the usual operator norm, vertical bar A vertical bar = (A * A)(1/2) , and I is the identity operator.

引用

页码：439 / 449

页数：11

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