Results 1 to 10 of about 768,175 (328)
Generalized Cauchy–Schwarz Inequalities and A-Numerical Radius Applications [PDF]
Axioms, 2023 The purpose of this research paper is to introduce new Cauchy–Schwarz inequalities that are valid in semi-Hilbert spaces, which are generalizations of Hilbert spaces.
Najla Altwaijry +2 more
doaj +2 more sources
The Upper Bounds of the Numerical Radius on Hilbert C*-Modules [PDF]
AxiomsIn this paper, we give the generalized Cauchy–Schwarz inequality and an extension of Buzano inequality on quasi-Hilbert C*-modules. Additionally, the upper bounds of the numerical radius of bounded adjointable operators on Hilbert C*-modules are improved.
Jing Liu, Deyu Wu, Alatancang Chen
doaj +2 more sources
On the Bishop-Phelps-Bollobás Property for Numerical Radius [PDF]
Abstract and Applied Analysis, 2014 We study the Bishop-Phelps-Bollobás property for numerical radius (in short, BPBp-nu) and find sufficient conditions for Banach spaces to ensure the BPBp-nu. Among other results, we show that L1μ-spaces have this property for every measure μ.
Sun Kwang Kim +2 more
doaj +2 more sources
Numerical radius inequalities for Hilbert $C^*$-modules [PDF]
Mathematica Bohemica, 2022 We present a new method for studying the numerical radius of bounded operators on Hilbert $C^*$-modules. Our method enables us to obtain some new results and generalize some known theorems for bounded operators on Hilbert spaces to bounded adjointable ...
Sadaf Fakri Moghaddam +1 more
doaj +1 more source
Betterment for estimates of the numerical radii of Hilbert space operators [PDF]
AUT Journal of Mathematics and Computing, 2023 We give several inequalities involving numerical radii $\omega \left( \cdot \right)$ and the usual operator norm $\|\cdot\|$ of Hilbert space operators. These inequalities lead to a considerable improvement in the well-known inequalities\begin{equation*}\
Mohammad Davarpanah, Hamid Moradi
doaj +1 more source
Some class of numerical radius peak $n$-linear mappings on $l_p$-spaces
Математичні Студії, 2022 For $n\geq 2$ and a real Banach space $E,$ ${\mathcal L}(^n E:E)$ denotes the space of all continuous $n$-linear mappings from $E$ to itself. Let $$\Pi(E)=\Big\{[x^*, (x_1, \ldots, x_n)]: x^{*}(x_j)=\|x^{*}\|=\|x_j\|=1~\mbox{for}~{j=1, \ldots, n}\Big\}.$$
S. G. Kim
doaj +1 more source
Further Accurate Numerical Radius Inequalities
Axioms, 2023 The goal of this study is to refine some numerical radius inequalities in a novel way. The new improvements and refinements purify some famous inequalities pertaining to Hilbert space operators numerical radii.
Tariq Qawasmeh +4 more
doaj +1 more source
AIMS Mathematics, 2023 We provide a number of sharp inequalities involving the usual operator norms of Hilbert space operators and powers of the numerical radii. Based on the traditional convexity inequalities for nonnegative real numbers and some generalize earlier numerical ...
Mohammad H. M. Rashid , Feras Bani-Ahmad
doaj +1 more source
Some Generalized Euclidean Operator Radius Inequalities
Axioms, 2022 In this work, some generalized Euclidean operator radius inequalities are established. Refinements of some well-known results are provided. Among others, some bounds in terms of the Cartesian decomposition of a given Hilbert space operator are proven.
Mohammad W. Alomari +2 more
doaj +1 more source
Schur multiplier operator and matrix inequalities [PDF]
Journal of Mahani Mathematical Research, 2023 In this note we obtain a reverse version of the Haagerup Theorem. In particular, if $ A \in \mathbb{M}_{n}$ has a $ 2\times2- $ principal submatrix as $ \left[ \begin{array}{cc}1& \alpha \\\beta & 1\\\end{array}\right]$ with $ \beta \neq \bar{\alpha ...
Alemeh Sheikhhosseini
doaj +1 more source