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Related papers: Jensen's operator inequality and its converses

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We systematically study how properties of abstract operator systems help classifying linear matrix inequality definitions of sets. Our main focus is on polyhedral cones, the 3-dimensional Lorentz cone, where we can completely describe all…

Functional Analysis · Mathematics 2023-01-27 Martin Berger , Tom Drescher , Tim Netzer

We study conditional expectations generated by an abelian $ C^* $-subalgebra in the centralizer of a positive functional. We formulate and prove Jensen's inequality for functions of several variables with respect to this type of conditional…

Operator Algebras · Mathematics 2007-05-23 Frank Hansen

K-frame theory was recently introduced to reconstruct elements from the range of a bounded linear operator K in a separable Hilbert space. This significant property is worthwhile especially in some problems arising in sampling theory. Some…

Functional Analysis · Mathematics 2017-05-30 Fahimeh Arabyani Neyshaburi , Ghadir Mohajeri Minaei , Ehsan Anjidani

In this paper, we present generalized P\'olya-Szeg\"o type inequalities for positive invertible operators on a Hilbert space for arbitrary operator means between the arithmetic and the harmonic means. As applications, we present Operator…

Functional Analysis · Mathematics 2020-01-07 Trung Hoa Dinh , Hamid Reza Moradi , Mohammad Sababheh

In this paper, we provide some inequalities for $P$-class functions and self-adjoint operators on a Hilbert space including an operator version of the Jensen's inequality and the Hermite-Hadamard's type inequality. We improve the…

Functional Analysis · Mathematics 2020-01-22 Ismail Nikoufar , Davuod Saeedi

We will consider about some inequalities on operator means for more than three operators, for instance, ALM and BMP geometric means will be considered. Moreover, log-Euclidean and logarithmic means for several operators will be treated.

Functional Analysis · Mathematics 2019-12-19 Shuhei Wada , Takeaki Yamazaki

Using the properties of geometric mean, we shall show for any $0\le \alpha ,\beta \le 1$, \[f\left( A{{\nabla }_{\alpha }}B \right)\le f\left( \left( A{{\nabla }_{\alpha }}B \right){{\nabla }_{\beta }}A \right){{\sharp}_{\alpha }}f\left(…

Functional Analysis · Mathematics 2018-08-28 Hamid Reza Moradi , Shigeru Furuichi , Mohammad Sababheh

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

We present a Diaz--Metcalf type operator inequality as a reverse Cauchy-Schwarz inequality and then apply it to get the operator versions of P\'{o}lya-Szeg\"{o}'s, Greub-Rheinboldt's, Kantorovich's, Shisha-Mond's, Schweitzer's, Cassels' and…

Functional Analysis · Mathematics 2012-03-22 M. S. Moslehian , R. Nakamoto , Y. Seo

In this paper, we introduce the notion of conditional $h$-convex functions and we prove an operator version of the Jensen inequality for conditional $h$-convex functions. Using this type of functions, we give some refinements for Ky-Fan's…

Functional Analysis · Mathematics 2022-10-11 Ismail Nikoufar , Davuod Saeedi

Some concepts, such as non-compactness measure and condensing operators, defined on metric spaces are extended to uniform spaces. Such extensions allow us to locate, in the context of uniform spaces, some classical results existing in…

General Topology · Mathematics 2015-11-25 Raúl Fierro

In this article we present some new comparisons between the Heinz and Heron operator means, which improve some recent results known from the literature. We derive some refinements of these inequalities for unitarily invariant norms with the…

Functional Analysis · Mathematics 2021-05-11 A. G. Ghazanfari

Some sharp inequalities of Gruss type for sequences of vectors in real or complex inner product spaces are obtained. Applications for Jensen's inequality for convex functions defined on such spaces are also provided.

Classical Analysis and ODEs · Mathematics 2025-10-20 Sever Silvestru Dragomir

In this paper, we study the existence of solutions of some kinds of operator equations via operator inequalities. First, we investigate characterizations of operator order $A\geqslant B >0$ and chaotic operator order log $A \geqslant$ log…

Functional Analysis · Mathematics 2011-08-16 Jian Shi , Zongsheng Gao

It is well-known that if a real valued function acting on a convex set satisfies the $n$-variable Jensen inequality, for some natural number $n\geq 2$, then, for all $k\in\{1,\dots, n\}$, it fulfills the $k$-variable Jensen inequality as…

Classical Analysis and ODEs · Mathematics 2017-06-29 Tibor Kiss , Zsolt Páles

In this paper, we study refinements of some inequalities related to Young inequality for scalar and for operator. As our main results, we show refined Young inequalities for two positive operators. This results refine the ordering relations…

Functional Analysis · Mathematics 2012-01-27 Shigeru Furuichi , Minghua Lin

In the paper, we introduce the generalized convex function on fractal sets of real line numbers and study the properties of the generalized convex function. Based on these properties, we establish the generalized Jensen inequality and…

Classical Analysis and ODEs · Mathematics 2014-06-30 Huixia Mo , Xin Sui , Dongyan Yu

We introduce the notion of regular operator mappings of several variables generalising the notion of spectral function. This setting is convenient for studying maps more general than what can be obtained from the functional calculus, and it…

Functional Analysis · Mathematics 2014-07-23 Frank Hansen

We present some reverse Young-type inequalities for the Hilbert-Schmidt norm as well as any unitarily invariant norm. Furthermore, we give some inequalities dealing with operator means. More precisely, we show that if $A, B\in {\mathfrak…

Functional Analysis · Mathematics 2021-07-23 Mojtaba Bakherad , Mario Krnic , Mohammad Sal Moslehian

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