关于ρ算子半径的透视

IF 1.2 3区 数学 Q1 MATHEMATICS
Pintu Bhunia , Mohammad Sal Moslehian , Ali Zamani
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Using techniques involving the Kronecker product, it is shown that<span><span><span><math><mrow><mfrac><mrow><mn>1</mn><mo>+</mo><mo>|</mo><mn>1</mn><mo>−</mo><mi>ρ</mi><mo>|</mo></mrow><mrow><mi>ρ</mi></mrow></mfrac><mi>w</mi><mo>(</mo><mi>X</mi><mo>)</mo><mo>≤</mo><msub><mrow><mi>w</mi></mrow><mrow><mi>ρ</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo><mo>≤</mo><mfrac><mrow><mn>2</mn></mrow><mrow><mi>ρ</mi></mrow></mfrac><mi>w</mi><mo>(</mo><mi>X</mi><mo>)</mo><mo>,</mo></mrow></math></span></span></span> where <span><math><mi>w</mi><mo>(</mo><mi>X</mi><mo>)</mo></math></span> is the numerical radius of <em>X</em>. These bounds for <span><math><msub><mrow><mi>w</mi></mrow><mrow><mi>ρ</mi></mrow></msub><mo>(</mo><mi>X</mi><mo>)</mo></math></span> are sharper than those presented by J. A. R. Holbrook. Furthermore, the cases of equality are investigated. We prove that the <em>ρ</em>-operator radius exposes certain operators as projections. 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We establish new inequalities for the <em>ρ</em>-operator radius, focusing on the sum and product of operators. 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引用次数: 0

摘要

设ρ∈(0,2),设wρ(X)为Hilbert空间算子X的ρ算子半径。利用涉及Kronecker积的技术,证明了1+|1−ρ|ρw(X)≤wρ(X)≤2ρw(X),其中w(X)为X的数值半径。这些wρ(X)的界比J. a . R. Holbrook给出的界更清晰。此外,还研究了相等的情况。我们证明了ρ算子半径将某些算子暴露为投影。建立了关于ρ算子半径的新不等式,重点讨论了算子的和与积。对于算子X的广义Aluthge变换X ~ t,证明了不等式wρ(X)≤12wρ(X ~ t)+1ρ‖X‖,对于所有∈[0,1]。所导出的不等式推广和推广了经典算子范数和数值半径的几个著名结果。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Perspectives on the ρ-operator radius
Let ρ(0,2] and let wρ(X) be the ρ-operator radius of a Hilbert space operator X. Using techniques involving the Kronecker product, it is shown that1+|1ρ|ρw(X)wρ(X)2ρw(X), where w(X) is the numerical radius of X. These bounds for wρ(X) are sharper than those presented by J. A. R. Holbrook. Furthermore, the cases of equality are investigated. We prove that the ρ-operator radius exposes certain operators as projections. We establish new inequalities for the ρ-operator radius, focusing on the sum and product of operators. For the generalized Aluthge transform X˜t of an operator X, we prove the inequality:wρ(X)12wρ(X˜t)+1ρX,for allt[0,1]. The derived inequalities extend and generalize several well-known results for the classical operator norm and numerical radius.
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来源期刊
CiteScore
2.50
自引率
7.70%
发文量
790
审稿时长
6 months
期刊介绍: The Journal of Mathematical Analysis and Applications presents papers that treat mathematical analysis and its numerous applications. The journal emphasizes articles devoted to the mathematical treatment of questions arising in physics, chemistry, biology, and engineering, particularly those that stress analytical aspects and novel problems and their solutions. Papers are sought which employ one or more of the following areas of classical analysis: • Analytic number theory • Functional analysis and operator theory • Real and harmonic analysis • Complex analysis • Numerical analysis • Applied mathematics • Partial differential equations • Dynamical systems • Control and Optimization • Probability • Mathematical biology • Combinatorics • Mathematical physics.
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