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Related papers: Modulus of convexity for operator convex functions

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We present some generalized Jensen type operator inequalities involving sequences of self-adjoint operators. Among other things, we prove that if $f:[0,\infty) \to \mathbb{R}$ is a continuous convex function with $f(0)\leq 0$, then…

Functional Analysis · Mathematics 2014-11-04 M. S. Moslehian , J. Micic , M. Kian

In this paper, we state some characterizations of $h$-convex function is defined on a convex set in a linear space. By doing so, we extend the Jensen-Mercer inequality for $h$-convex function. We will also define $h$-convex function for…

Functional Analysis · Mathematics 2020-03-31 M. Abbasi , A. Morassaei , F. Mirzapour

This paper concerns three classes of real-valued functions on intervals, operator monotone functions, operator convex functions, and strongly operator convex functions. Strongly operator convex functions were previously treated in [3] and…

Functional Analysis · Mathematics 2018-05-29 Lawrence G. Brown , Mitsuru Uchiyama

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

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

In [B1, Theorem 2.36] we proved the equivalence of six conditions on a continuous function f on an interval. These conditions define a subset of the set of operator convex functions, whose elements are called strongly operator convex. Two…

Functional Analysis · Mathematics 2018-02-21 Lawrence G. Brown

Convex functions have played a major role in the field of Mathematical inequalities. In this paper, we introduce a new concept related to convexity, which proves better estimates when the function is somehow more convex than another. In…

Functional Analysis · Mathematics 2020-03-25 M. Sababheh , S. Furuichi , H. R. Moradi

We study the convolution function $$ C[f(x)] := \int_1^x f(y)f({x\over y}) {{\rm d} y\over y} $$ when $f(x)$ is a suitable number-theoretic error term. Asymptotics and upper bounds for $C[f(x)]$ are derived from mean square bounds for…

Number Theory · Mathematics 2010-11-03 Aleksandar Ivic

Operator convex functions defined on the positive half-line play a prominent role in the theory of quantum information, where they are used to define quantum $f$-divergences. Such functions admit integral representations in terms of…

Optimization and Control · Mathematics 2023-05-23 Oisín Faust , Hamza Fawzi

In this paper, we prove some operator inequalities associated with an extension of the Kantorovich type inequality for $s$-convex function. We also give an application to the order preserving power inequality of three variables and find a…

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

Let $A$ be a positive definite operator on a Hilbert space $H$, and $|||.|||$ be a unitarily invariant norm on $B(H)$. We show that if $f$ is an operator monotone function on $(0,\infty)$ and $n\in \mathbb{N}$, then $|||D^n…

Functional Analysis · Mathematics 2021-05-13 Amir Ghasem Ghazanfari

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

We show that the symmetrized product $AB+BA$ of two positive operators $A$ and $B$ is positive if and only if $f(A+B)\leq f(A)+f(B)$ for all non-negative operator monotone functions $f$ on $[0,\infty)$ and deduce an operator inequality. We…

Functional Analysis · Mathematics 2012-03-21 M. S. Moslehian , H. Najafi

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

We mainly establish a monotonicity property between some special Riemann sums of a convex function $f$ on $[a,b]$, which in particular yields that $\frac{b-a}{n+1}\sum_{i=0}^n f\left(a+i\frac{b-a}{n}\right)$ is decreasing while…

Classical Analysis and ODEs · Mathematics 2014-10-07 Jamal Rooin , Hossein Dehghan

In this paper, we introduce operator geodesically convex and operator convex-log functions and characterize some properties of them. Then apply these classes of functions to present several operator Azc\'{e}l and Minkowski type inequalities…

Functional Analysis · Mathematics 2020-04-07 V. Kaleibary , M. R. Jabbarzadeh , S. Furuichi

In this paper, two new lemmas are proved and inequalities are established for co-ordinated convex functions and co-ordinated s-convex functions.

Classical Analysis and ODEs · Mathematics 2011-07-18 M. Emin Ozdemir , Havva Kavurmaci , Ahmet Ocak Akdemir , Merve Avci

We investigate the convexity property on $(0,1)$ of the functions $\varphi_{a,b,c}$ and $1/\varphi_{a,b,c}$, where $$\varphi_{a,b,c}(x)= \frac{c-\log(1-x)}{\,_2F_1(a,b,a+b,x)},$$ whenever $a,b\geq 0$ and $a+b\leq 1$. We Show that…

General Mathematics · Mathematics 2024-03-18 Mohamed Bouali

We introduce and investigate a new generalized convexity notion for functions called prox-convexity. The proximity operator of such a function is single-valued and firmly nonexpansive. We provide examples of (strongly) quasiconvex, weakly…

Optimization and Control · Mathematics 2021-11-30 Sorin-Mihai Grad , Felipe Lara

Let f be a non-negative concave function on the positive half-line. Let A and B be two positive matrices. Then, for all symmetric norms, || f(A+B) || is less than || f(A)+f(B) ||. When f is operator concave, this was proved by Ando and…

Functional Analysis · Mathematics 2007-05-23 Jean-Christophe Bourin , Mitsuru Uchiyama