Results 21 to 30 of about 4,538,824 (321)
A refinement of the Cauchy-Schwarz inequality accompanied by new numerical radius upper bounds
Filomat, 2023 This present work aims to ameliorate the celebrated Cauchy-Schwarz inequality and provide several new consequences associated with the numerical radius upper bounds of Hilbert space operators. More precisely, for arbitrary a, b ? H and ? ?
Mohammed Al-Dolat, Imad Jaradat
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Algorithms, 2022 In this work, some new inequalities for the numerical radius of block n-by-n matrices are presented. As an application, the bounding of zeros of polynomials using the Frobenius companion matrix partitioned by the Cartesian decomposition method is proved.
Mohammad W. Alomari, Christophe Chesneau
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An extension of the a-numerical radius on $$C^*$$-algebras [PDF]
Banach Journal of Mathematical Analysis, 2022 Let $a$ be a positive element in a unital $C^*$-algebra $\mathfrak{A}$. We define a semi-norm on $\mathfrak{A}$, which generalizes the $a$-operator semi-norm and the $a$-numerical radius.
M. Mabrouk, A. Zamani
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NUMERICAL RADIUS NORMS ON OPERATOR SPACES [PDF]
Journal of the London Mathematical Society, 2006 We introduce a numerical radius operator space $(X, \mathcal{W}_n)$. The conditions to be a numerical radius operator space are weaker than the Ruan's axiom for an operator space $(X, \mathcal{O}_n)$. Let $w(\cdot)$ be the numerical radius norm on $\mathbb{B}(\mathcal{H})$.
Itoh, T., Nagisa, M.
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Some Results on Polynomial Numerical Hulls of Perturbed Matrices [PDF]
Sahand Communications in Mathematical Analysis, 2019 In this paper, the behavior of the pseudopolynomial numerical hull of a square complex matrix with respect to structured perturbations and its radius is investigated.
Madjid Khakshour, Gholamreza Aghamollaei
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Further refinements of some numerical radius inequalities for operators
Operators and Matrices, 2023 . In this work, we give re fi nements of some well-known numerical radius inequalities. Also, we present an improvement of the triangle inequality for the operator norm. Mathematics subject classi fi cation (2020): 47A12, 47A30, 47B15.
Soumia Soltani, Abdelkader Frakis
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Gap Between Operator Norm and Spectral Radius for the Square of Antidiagonal Block Operator Matrices
Communications in Advanced Mathematical Sciences, 2022 In this work, the gap between operator norm and spectral radius for the square of antidiagonal block operator matrices in the direct sum of Banach spaces has been investigated, and also the gap between operator norm and numerical radius for the square of
Elif Otkun Çevik
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Numerical radius in Hilbert C✻-modules [PDF]
Mathematical Inequalities & Applications, 2021 Utilizing the linking algebra of a Hilbert $C^*$-module $\big(\mathscr{V}, {\|\!\cdot\!\|}\big)$, we introduce $ (x)$ as a definition of numerical radius for an element $x\in\mathscr{V}$ and then show that $ (\cdot)$ is a norm on $\mathscr{V}$ such that $\frac{1}{2}{\|x\|} \leq (x) \leq {\|x\|}$. In addition, we obtain an equivalent condition for $
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Generalized numerical radius and related inequalities [PDF]
Operators and Matrices, 2021 They proved several properties and introduced some inequalities. We continue with the study of this generalized numerical radius and we develop diverse inequalities involving w_N. We also study particular cases with a fixed N(.), for instance the p-Schatten norms. In ["A generalization of the numerical radius". Linear Algebra Appl.
Bottazzi, Tamara Paula +1 more
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Journal of Mathematical Inequalities, 2023 . In this article, we give new upper and lower bounds of numerical radius and Hilbert-Schmidt numerical radius inequalities for Hilbert space operators.
Chao un Yang, Ming ua Xu
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