English
Related papers

Related papers: Operator Jensen's inequality for operator superqua…

200 papers

The main target of this paper is to discuss operator Hermite--Hadamard inequality for convex functions, without appealing to operator convexity. Several forms of this inequality will be presented and some applications including norm and…

Functional Analysis · Mathematics 2019-08-07 Hamid Reza Moradi , Mohammad Sababheh , Shigeru Furuichi

In this note we describe some results concerning upper and lower bounds for the Jensen functional. We use several known and new results to shed light on the concepts of superterzatic functions.

Classical Analysis and ODEs · Mathematics 2016-05-13 Flavia-Corina Mitroi-Symeonidis

We discuss when an operator, subject to a rather general inequality in hereditary form, admits a unitarily equivalent functional model of Agler type in the reproducing kernel Hilbert space associated to the inequality. To the contrary to…

Functional Analysis · Mathematics 2020-07-06 Luciano Abadias , Glenier Bello-Burguet , Dmitry Yakubovich

Jensen inequalities for positive linear maps of Choi and Hansen-Pedersen type are established for a large class of operator/matrix means. These results are also extensions of the Minkowski determinantal inequality. To this end we develop…

Functional Analysis · Mathematics 2011-09-15 Jean-Christophe Bourin , Fumio Hiai

In this paper we first introduce the Heron and Heinz means of two convex functionals. Afterwards, some inequalities involving these functional means are investigated. The operator versions of our theoretical functional results are…

Functional Analysis · Mathematics 2018-12-20 Mustapha Raïssouli , Shigeru Furuichi

In this paper we establish a Hermite- Hadamard type inequality for operator preinvex functions and an estimate of the right hand side of a Hermite- Hadamard type inequality in which some operator preinvex functions of selfadjoint operators…

Functional Analysis · Mathematics 2013-06-05 A. G. Ghazanfari , M. Shakoori , A. Barani , S. S. Dragomir

In this work, the mixed Schwarz inequality for semi-Hilbertian space operators is proved. Namely, for every positive Hilbert space operator $A$. If $f$ and $g$ are nonnegative continuous functions on $\left[0,\infty\right)$ satisfying…

Functional Analysis · Mathematics 2020-07-06 Mohammad W. Alomari

In this paper we introduce operator preinvex functions and es- tablish a Hermite-Hadamard type inequality for such functions. We give an estimate of the right hand side of a Hermite-Hadamard type inequality in which some operator preinvex…

Functional Analysis · Mathematics 2014-12-19 A. G. Ghazanfari , A. Barani

We consider a Hilbert space that is a product of a finite number of Hilbert spaces and operators that are represented by "componental operators" acting on the Hilbert spaces that form the product space. We attribute operatorial properties…

Functional Analysis · Mathematics 2021-11-30 Andrzej Cegielski , Yair Censor

We prove a matrix inequality for convex functions of a Hermitian matrix on a bipartite space. As an application we reprove and extend some theorems about eigenvalue asymptotics of Schr\"odinger operators with homogeneous potentials. The…

Mathematical Physics · Physics 2025-02-14 Eric A. Carlen , Rupert L. Frank , Simon Larson

The divergence-like operator on an odd symplectic superspace which acts invariantly on a specially chosen odd vector field is considered. This operator is used to construct an odd invariant semidensity in a geometrically clear way. The…

dg-ga · Mathematics 2009-10-30 O. M. Khudaverdian

In general, it is a non trivial task to determine the adjoint $S^*$ of an unbounded operator $S$ acting between two Hilbert spaces. We provide necessary and sufficient conditions for a given operator $T$ to be identical with $S^*$. In our…

Functional Analysis · Mathematics 2017-11-23 Zoltán Sebestyén , Zsigmond Tarcsay

This paper is concerned with a certain aspect of the spectral theory of unitary operators in a Hilbert space and its aim is to give an explicit construction of continuous functions of unitary operators. Starting from a given unitary…

Functional Analysis · Mathematics 2014-03-11 Krzysztof Zajkowski

In this paper, we give the refinement of an extension of Jensen's inequality to affine combinations. Furthermore, we present the functional form of Jensen's inequality for continuous 3-convex functions of one variable at a point.

Classical Analysis and ODEs · Mathematics 2016-01-25 Imran Abbas Baloch , Silvestru Sever Dragomir

In this article, we present exponential-type inequalities for positive linear mappings and Hilbert space operators, by means of convexity and the Mond-Pe\v cari\'c method. The obtained results refine and generalize some known results. As an…

Functional Analysis · Mathematics 2018-08-02 M. Sababheh , H. R. Moradi , S. Furuichi

Some rearrangement inequalities for symmetric norms on matrices are given as well as related results for operator convex functions.

Functional Analysis · Mathematics 2007-05-23 Jean-Christophe Bourin

We consider operators acting on a Hilbert space that can be written as the sum of a shift and a diagonal operator and determine when the operator is hyponormal. The condition is presented in terms of the norm of an explicit block Jacobi…

Classical Analysis and ODEs · Mathematics 2021-08-11 Trieu Le , Brian Simanek

In this article, we present a new subadditivity behavior of convex and concave functions, when applied to Hilbert space operators. For example, under suitable assumptions on the spectrum of the positive operators $A$ and $B$, we prove that…

Functional Analysis · Mathematics 2019-04-29 Hamid Reza Moradi , Zahra Heydarbeygi , Mohammad Sababheh

Given an nxn doubly stochastic matrix P satisfying an appropriate condition of linear algebraic-type, and a function f defined on a nonempty interval, we show that the validity of a convexity-type functional inequality for f in terms P…

Classical Analysis and ODEs · Mathematics 2025-10-07 Matyas Barczy , Zsolt Páles

Convergence of operators acting on a given Hilbert space is an old and well studied topic in operator theory. The idea of introducing a related notion for operators acting on arying spaces is natural. However, it seems that the first…

Functional Analysis · Mathematics 2014-01-17 Delio Mugnolo , Robin Nittka , Olaf Post