English
Related papers

Related papers: Berezin number inequalities for Hilbert space oper…

200 papers

We extend a work of Pedersen and Takesaki by giving some equivalent conditions for the existence of a positive solution of the so-called Pedersen--Takesaki operator equation $XHX=K$ in the setting of Hilbert $C^*$-modules. It is known that…

Operator Algebras · Mathematics 2021-11-25 R. Eskandari , X. Fang , M. S. Moslehian , Q. Xu

Let $P(z)$ be a polynomial of degree $n\geq 1$. In this paper we define an operator $B$, as following, $$B[P(z)]:=\lambda_0 P(z)+\lambda_1 (\frac{nz}{2}) \frac{P'(z)}{1!}+\lambda_2 (\frac{nz}{2})^2 \frac{P''(z)}{2!},$$ where…

Complex Variables · Mathematics 2009-03-06 M. Ahmadi Baseri , M. Bidkham , M. Eshaghi Gordji

The consequences for Berezin's quantization on symmetric spaces of the identity of the set of coherent vectors orthogonal to a fixed one with the cut locus are stated precisely. It is shown that functions expressing the coherent states, the…

dg-ga · Mathematics 2009-10-30 S. Berceanu

Let $\mathcal{B}(\mathcal{H})$ be the algebra of all bounded linear operators on a complex Hilbert space $\mathcal{H}$. In this paper, we first establish several sharp improved and refined versions of the Bohr's inequality for the functions…

Functional Analysis · Mathematics 2026-04-15 Vasudevarao Allu , Himadri Halder

Given Hilbert space operators $A_i, B_i$, $i=1,2$, and $X$ such that $A_1$ commutes with $A_2$ and $B_!$ commutes with $B_2$, and integers $m, n\geq 1$, we say that the pairs of operators $(B_1,A_1)$ and $(B_2,A_2)$ are left-$(X,…

Functional Analysis · Mathematics 2020-10-30 B. P. Duggal , I. H. Kim

An improvement to a Berezin-Li-Yau type inequality for $(-\Delta)^{\alpha/2}|_{\Omega},$ the fractional Laplacian operators restriced to a bounded domain $\Omega\subset \mathbb{R}^d$ for $\alpha\in(0,2],$ $d\ge 2,$ is proved.

Spectral Theory · Mathematics 2013-12-18 Selma Yildirim Yolcu , Turkay Yolcu

We study various inequalities for numerical radius and Berezin number of a bounded linear operator on a Hilbert space. It is proved that the numerical radius of a pure two-isometry is 1 and the Crawford number of a pure two-isometry is 0.…

Functional Analysis · Mathematics 2022-07-05 Satyabrata Majee , Amit Maji , Atanu Manna

In this work, an improvement of H\"{o}lder-McCarty inequality is established. Based on that, several refinements of the generalized mixed Schwarz inequality are obtained. Consequently, some new numerical radius inequalities are proved. New…

Functional Analysis · Mathematics 2019-03-06 Mohammad W. Alomari

In this work, we improve and refine some numerical radius inequalities. In particular, for all Hilbert space operators $T$, the celebrated Kittaneh inequality reads: \begin{align*} \frac{1}{4}\left\| T^*T + TT^*\right\|\le w^{2 }\left(T…

Functional Analysis · Mathematics 2019-12-04 Mohammad W. Alomari

Several upper and lower bounds for the numerical radius of $2 \times 2$ operator matrices are developed which refine and generalize the earlier related bounds. In particular, we show that if $B,C$ are bounded linear operators on a complex…

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

In this paper, we give some refinements for the second inequality in $\frac{1}{2}\|A\| \leq w(A) \leq \|A\|$, where $A\in B(H)$. In particular, if $A$ is hyponormal by refining the Young inequality with the Kantorovich constant $K(\cdot,…

Functional Analysis · Mathematics 2020-10-13 Zahra Heydarbeygi , Maryam Amyari , Mahnaz Khanehgir

This is a sequel to a series of works, where we studied the local aspects of the asymptotic action of deformation quantization on the Hilbert spaces $H^0(X, L^{\otimes k})$ of geometric quantization for a K\"ahler manifold $X$; here $L$ is…

Differential Geometry · Mathematics 2025-11-24 Kwokwai Chan , Naichung Conan Leung , Qin Li , Yutung Yau

Multipartite nonlocality is of great fundamental interest and constitutes a useful resource for many quantum information protocols. However, demonstrating it in practice, by violating a Bell inequality, can be difficult. In particular,…

Quantum Physics · Physics 2015-06-25 Celal Furkan Senel , Thomas Lawson , Marc Kaplan , Damian Markham , Eleni Diamanti

We obtain new lower and upper bounds for the numerical radius of a bounded linear operator $A$ on a complex Hilbert space, which refine the existing ones. In particular, if $w(A)$ and $\|A\|$ denote the numerical radius and operator norm of…

Functional Analysis · Mathematics 2026-03-05 Pintu Bhunia , Rukaya Majeed

In respect of b-linear functional, Riesz representation theorem in n-Hilbert space have been proved. We define b-sesquilinear functional in n-Hilbert space and establish the polarization identities. A generalized form of the Schwarz…

Functional Analysis · Mathematics 2023-04-12 Prasenjit Ghosh , T. K. Samanta

We develope new lower bounds for the $A$-numerical radius of semi-Hilbertian space operators, and applying these bounds we obtain upper bounds for the $A$-numerical radius of the commutators of operators. The bounds obtained here improve on…

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

Bell's inequality plays an important role with respect to the Einsteinian question about the physical reality of quantum theory. While Bell's inequality is usually viewed within the geometric framework of a Hilbert space quantum model, the…

Quantum Physics · Physics 2023-04-26 Ulrich Faigle

In this paper, we achieve new and improved numerical radius inequalities of operators defined on a Hilbert space by using Orlicz function and Hermite-Hadamard inequality. The upper bounds of various inequalities involving numerical radii…

Functional Analysis · Mathematics 2024-04-08 Amit Maji , Atanu Manna , Ram Mohapatra

In this paper we consider the generalized little Hankel and Berezin type operators on Besov spaces of holomorphic functions on polydiscs and give results about the boundedness of these operators.

Functional Analysis · Mathematics 2016-09-20 Anahit V. Harutyunyan , George Marinescu

Some special Hilbert spaces are introduced to present the class of infinitesimal operators with complete minimal non-basis family of eigenvectors. The discrete Hardy inequality plays an important role in the proposed approach. The…

Spectral Theory · Mathematics 2016-08-25 Grigory M. Sklyar , Vitalii Marchenko