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Related papers: Further numerical radius inequalities

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In this paper, we present some upper bounds for unitarily invariant norms inequalities. Among other inequalities, we show some upper bounds for the Hilbert-Schmidt norm. In particular, we prove \begin{align*} \|f(A)Xg(B)\pm…

Functional Analysis · Mathematics 2018-01-10 Mojtaba Bakherad

In this paper, we develop several Euclidean operator radius inequalities of $d$-tuple operators, as well as the sum and the product of $d$-tuple operators. Also, we obtain a power inequality for the Euclidean operator radius. Further, we…

Functional Analysis · Mathematics 2023-04-18 Suvendu Jana , Pintu Bhunia , Kallol Paul

We get a new inequality on the Hodge number $h^{1,1}(S)$ of fibred algebraic complex surfaces $S$, which is a generalization of an inequality of Beauville. Our inequality implies the Arakelov type inequalities due to Arakelov, Faltings,…

Algebraic Geometry · Mathematics 2013-03-13 Jun Lu , Sheng-Li Tan , Fei Yu , Kang Zuo

Let $\mathcal{B}(\mathcal{H})$ denote the Banach algebra of all bounded linear operators acting on complex Hilbert spaces $\mathcal{H}$. In this paper, we first establish several sharply refined versions of Bohr's inequality analogues with…

Complex Variables · Mathematics 2024-11-05 Vasudevarao Allu , Raju Biswas , Rajib Mandal

We present new bounds for the numerical radius of bounded linear operators and $2\times 2$ operator matrices. We apply upper bounds for the numerical radius to the Frobenius companion matrix of a complex monic polynomial to obtain new…

Functional Analysis · Mathematics 2020-01-28 Pintu Bhunia , Santanu Bag , Raj Kumar Nayak , Kallol Paul

Some new trace inequalities for operators in Hilbert spaces are provided. The superadditivity and monotonicity of some associated functionals are investigated and applications for power series of such operators are given. Some trace…

Functional Analysis · Mathematics 2014-09-24 Silvestru Sever Dragomir

The numerical radius of a matrix is a scalar quantity that has many applications in the study of matrix analysis. Due to the difficulty in computing the numerical radius, inequalities bounding it have received a considerable attention in…

Functional Analysis · Mathematics 2020-07-20 Yassine Bedrani , Fuad Kittaneh , Mohammed Sababheh

We study a generalized spherical means operator, viz. generalized spherical mean Radon transform, acting on radial functions. As the main results, we find conditions for the associated maximal operator and its local variant to be bounded on…

Classical Analysis and ODEs · Mathematics 2020-10-22 Óscar Ciaurri , Adam Nowak , Luz Roncal

We give a lower bound on the Hodge number h^{2,0}(X), where X is an irregular compact K\"ahler (or smooth complex projective) variety, in terms of the minimal rank of an element in the kernel of the wedge product map \psi_2: \Lambda^2…

Algebraic Geometry · Mathematics 2012-11-13 Víctor González-Alonso

We present new bounds for the Berezin number inequalities which improve on the existing bounds. We also obtain bounds for the Berezin norm of operators as well as the sum of two operators.

Functional Analysis · Mathematics 2022-02-09 Pintu Bhunia , Anirban Sen , Kallol Paul

We describe all isometries of the $q$-numerical radius on the space ${\mathcal K}(\mathcal H)$ of compact operators on a (possibly infinite-dimensional) Hilbert space $\mathcal H$.

Functional Analysis · Mathematics 2021-02-18 Maria Inez Cardoso Gonçalves , Vladimir G. Pestov

We obtain several upper and lower bounds for the numerical radius of sectorial matrices. We also develop several numerical radius inequalities of the sum, product and commutator of sectorial matrices. The inequalities obtained here are…

Functional Analysis · Mathematics 2024-08-14 Pintu Bhunia , Kallol Paul , Anirban Sen

We present several sharp upper bounds and some extension for product operators. Among other inequalities, it is shown that if , , are non-negative continuous functions on such that , , then for all non-negative operator monotone decreasing…

Functional Analysis · Mathematics 2020-04-22 Hosna Jafarmanesh , Maryam Khosravi

Utilizing the linking algebra of a Hilbert $C^*$-module $\big(\mathscr{V}, {\|\!\cdot\!\|}\big)$, we introduce $\Omega(x)$ as a definition of numerical radius for an element $x\in\mathscr{V}$ and then show that $\Omega(\cdot)$ is a norm on…

Functional Analysis · Mathematics 2021-12-01 Ali Zamani

We prove new inequalities for the spectral radius, essential spectral radius, operator norm, measure of noncompactness and numerical radius of Hadamard weighted geometric means of positive kernel operators on Banach function and sequence…

Functional Analysis · Mathematics 2022-02-01 Katarina Bogdanović , Aljoša Peperko

Suppose $L(H)$ is the space of all bounded linear operators on a complex Hilbert space $H.$ This article deals with the problem of characterizing the extreme contractions of $L(H)$ with respect to the numerical radius norm on $L(H).$ In…

Functional Analysis · Mathematics 2022-10-19 Arpita Mal

We observe that the classical notion of numerical radius gives rise to a notion of smoothness in the space of bounded linear operators on certain Banach spaces, whenever the numerical radius is a norm. We demonstrate an important class of…

Functional Analysis · Mathematics 2021-07-09 Saikat Roy , Debmalya Sain

Lebesgue space inequalities are proved for a variant of the triangular Hilbert transform involving curvature. The analysis relies on a crucial trilinear smoothing inequality developed herein, and on bounds for an anisotropic variant of the…

Classical Analysis and ODEs · Mathematics 2021-08-04 Michael Christ , Polona Durcik , Joris Roos

New results related to the Bombieri generalisation of Bessel's inequality in inner product spaces are given.

Classical Analysis and ODEs · Mathematics 2007-05-23 Sever Silvestru Dragomir

We study Birkhoff-James orthogonality of compact (bounded) linear operators between Hilbert spaces and Banach spaces. Applying the notion of semi-inner-products in normed linear spaces and some related geometric ideas, we generalize and…

Functional Analysis · Mathematics 2018-10-12 Debmalya Sain , Kallol Paul , Arpita Mal