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Related papers: Operator inequalities of Jensen type

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Let $\mathcal{A}$ be a $C^*$-algebra and $\phi:\cA\to L(H)$ be a positive unital map. Then, for a convex function $f:I\to \mathbb{R}$ defined on some open interval and a self-adjoint element $a\in \mathcal{A}$ whose spectrum lies in $I$, we…

Functional Analysis · Mathematics 2007-05-23 Jorge Antezana , Pedro Massey , Demetrio Stojanoff

This paper is mainly devoted to studying operator Jensen inequality. More precisely, a new generalization of Jensen inequality and its reverse version for convex (not necessary operator convex) functions have been proved. Several special…

Functional Analysis · Mathematics 2019-06-10 M. Shah Hosseini , H. R. Moradi , B. Moosavi

Mercer inequality for convex functions is a variant of Jensen's inequality, with an operator version that is still valid without operator convexity. This paper is two folded. First, we present a Mercer-type inequality for operators without…

Functional Analysis · Mathematics 2020-03-06 H. R. Moradi , S. Furuichi , M. Sababheh

We establish what we consider to be the definitive versions of Jensen's operator inequality and Jensen's trace inequality for functions defined on an interval. This is accomplished by the introduction of genuine non-commutative convex…

Operator Algebras · Mathematics 2007-05-23 Frank Hansen , Gert K. Pedersen

Inequalities play an important role in pure and applied mathematics. In particular, Jensen's inequality, one of the most famous inequalities, plays a main role in the study of the existence and uniqueness of initial and boundary value…

Classical Analysis and ODEs · Mathematics 2022-02-09 Yamilet Quintana , José M. Rodríguez , José M. Sigarreta Almira

Motivated by some recently established operator Jensen-type inequalities related to a usual convexity, in the present paper we derive several more accurate operator Jensen-type inequalities for certain subclasses of convex functions. More…

Functional Analysis · Mathematics 2018-05-11 Mojtaba Bakherad , Mohsen Kian , Mario Krnic , Seyyed Alireza Ahmadi

Let $p$ be a positive number and $h$ a function on $\mathbb{R}^+$ satisfying $h(xy) \ge h(x) h(y)$ for any $x, y \in \mathbb{R}^+$. A non-negative continuous function $f$ on $K (\subset \mathbb{R}^+)$ is said to be {\it operator…

Functional Analysis · Mathematics 2017-12-22 Trung Hoa Dinh , Khue TB Vo

We introduce the notion of Krein-operator convexity in the setting of Krein spaces. We present an indefinite version of the Jensen operator inequality on Krein spaces by showing that if $(\mathscr{H},J)$ is a Krein space, $\mathcal{U}$ is…

Functional Analysis · Mathematics 2014-11-04 M. S. Moslehian , M. Dehghani

This is a conitunation of [1] and [2]. We prove that if function $f$ belongs to the class $\Lambda_{\omega} \overset{\text{def}}{=} \{f: \omega_{f}(\delta)\leq \text{const} \omega(\delta)\} $ for an arbitrary modulus of continuity $\omega$,…

Functional Analysis · Mathematics 2016-05-18 Qinbo Liu

In this paper functions $f:D\to\mathbb{R}$ satisfying the inequality \[ f\Big(\frac{x+y}{2}\Big)\leq\frac12f(x)+\frac12f(y) +\varphi\Big(\frac{x-y}{2}\Big) \qquad(x,y\in D) \] are studied, where $D$ is a nonempty convex subset of a real…

Classical Analysis and ODEs · Mathematics 2024-12-10 Gábor Marcell Molnár , Zsolt Páles

We give a Jensen operator inequality for strongly convex functions. As a corollary, we improve operator Holder-McCarthy inequality under suitable conditions.

Functional Analysis · Mathematics 2017-02-07 H. R. Moradi , R. Naseri

In this paper we use basic properties of strongly convex functions to obtain new inequalities including Jensen's type and Jensen-Mercer type inequalities. Applications for special means are pointed out as well. We also give a Jensen's…

Functional Analysis · Mathematics 2017-07-06 H. R. Moradi , M. E. Omidvar , M. Adil Khan , K. Nikodem

Jensen's operator inequality for convexifiable functions is obtained. This result contains classical Jensen's operator inequality as a particular case. As a consequence, a new refinement and a reverse of Young's inequality is given.

Functional Analysis · Mathematics 2018-01-11 Hamid Reza Moradi , Shigeru Furuichi , Flavia-Corina Mitroi-Symeonidis , Razieh Naseri

In this paper, we prove an operator version of the Jensen's inequality and its converse for $h$-convex functions. We provide a refinement of the Jensen type inequality for $h$-convex functions. Moreover, we prove the Hermite-Hadamard's type…

Functional Analysis · Mathematics 2022-01-19 Ismail Nikoufar , Davuod Saeedi

Given a function $f$ defined on a nonempty and convex subset of the $d$-dimensional Euclidean space, we prove that if $f$ is bounded from below and it satisfies a convexity-type functional inequality with infinite convex combinations, then…

Classical Analysis and ODEs · Mathematics 2025-09-16 Matyas Barczy , Zsolt Páles

A considerable amount of literature in the theory of inequality is devoted to the study of Jensen's and Young's inequality. This article presents a number of new inequalities involving the log-convex functions and the geometrically convex…

Classical Analysis and ODEs · Mathematics 2022-02-10 Shigeru Furuichi , Hamid Reza Moradi , Supriyo Dutta

Given an operator convex function $f(x)$, we obtain an operator-valued lower bound for $cf(x) + (1-c)f(y) - f(cx + (1-c)y)$, $c \in [0,1]$. The lower bound is expressed in terms of the matrix Bregman divergence. A similar inequality is…

Quantum Physics · Physics 2015-06-17 Isaac H. Kim

We prove that a continuous function $f:(0,\infty) \to (0,\infty)$ is operator monotone increasing if and only if $f(A \: !_t \: B) \leqs f(A) \: !_t \: f(B)$ for any positive operators $A,B$ and scalar $t \in [0,1]$. Here, $!_t$ denotes the…

Functional Analysis · Mathematics 2015-06-24 Pattrawut Chansangiam

In this paper we deal with improvement of Jensen, Jensen-Steffensen's and Jensen's functionals related inequalities for uniformly convex, phi-convex and superquadratic functions.

Functional Analysis · Mathematics 2025-01-03 Shoshana Abramovich

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
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