Results 271 to 280 of about 4,538,824 (321)

New upper bounds for the numerical radius of Hilbert space operators

, 2021
In this paper we present new upper bounds for the numerical radius of bounded linear operators defined on a complex Hilbert space. Further we obtain estimations for upper bounds for the numerical radius of the sum of the product of bounded linear ...
Pintu Bhunia, K. Paul
semanticscholar   +1 more source

Development of inequalities and characterization of equality conditions for the numerical radius

, 2021
Let A be a bounded linear operator on a complex Hilbert space and ℜ ( A ) ( ℑ ( A ) ) denote the real part (imaginary part) of A. Among other refinements of the lower bounds for the numerical radius of A, we prove that w ( A ) ≥ 1 2 ‖ A ‖ + 1 2 | ‖ ℜ ( A
Pintu Bhunia, K. Paul
semanticscholar   +1 more source

Further inequalities for the 𝔸-numerical radius of certain 2 × 2 operator matrices

Georgian Mathematical Journal, 2022
Let 𝔸 = ( A O O A ) \mathbb{A}={\bigl{(}\begin{smallmatrix}A&O\\ O&A\\ \end{smallmatrix}\bigr{)}} be a 2 × 2 2\times 2 diagonal operator matrix whose each diagonal entry is a bounded positive (semi-definite) linear operator A acting on a complex Hilbert ...
Kais Feki, Satyajit Sahoo
semanticscholar   +1 more source

Power Inequalities for the Numerical Radius of a Product of Two Operators in Hilbert Spaces

Sarajevo Journal of Mathematics
Some power inequalities for the numerical radius of a product of two operators in Hilbert spaces with applications for commutators and self-commutators are given.   2000 Mathematics Subject Classification.
S. Dragomir
semanticscholar   +1 more source

Some numerical radius inequality for several semi-Hilbert space operators

Linear and multilinear algebra, 2022
The paper deals with the generalized numerical radius of linear operators acting on a complex Hilbert space , which are bounded with respect to the seminorm induced by a positive operator A on . Here A is not assumed to be invertible.
C. Conde, Kais Feki
semanticscholar   +1 more source

Some weighted numerical radius inequalities

Indian journal of pure and applied mathematics, 2022
The weighted numerical radius of a Hilbert space operator has been defined recently. This article explores other properties and uses this newly defined numerical radius to obtain several new interesting inequalities for the weighted numerical radius and ...
C. Conde, H. Moradi, M. Sababheh
semanticscholar   +1 more source

Berezin Number and Numerical Radius Inequalities

Vietnam Journal of Mathematics, 2023
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Anirban Sen, Kallol Paul
openaire   +1 more source

On p-numerical radius inequalities for commutators of operators

Quaestiones Mathematicae. Journal of the South African Mathematical Society
In this work, we give some p-numerical radius inequalities for operators as well as for commutators of operators. As applications, when p = ∞, we improve some earlier numerical radius inequalities for operators.
Abdelkader Frakis, F. Kıttaneh
semanticscholar   +1 more source

Subdifferential set of the joint numerical radius of a tuple of matrices

Linear and multilinear algebra, 2022
An expression for the subdifferential set of the joint numerical radius of a tuple of matrices is obtained. Its applications to the Birkhoff-James orthogonality in the space consisting of tuples of matrices equipped with the joint numerical radius norm ...
Priyanka Grover, Sushil Singla
semanticscholar   +1 more source

Improvements of $A$-numerical radius bounds

Hokkaido Mathematical Journal, 2023
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Nayak, Raj Kumar, Bhunia, Pintu, Paul, Kallol   +2 more
openaire   +2 more sources