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New upper and lower bounds for the numerical radii of Hilbert space operators are given. Among our results, we prove that if $A\in \mathcal{B} \left( \mathcal{H}\right) $ is a hyponormal operator, then for all non-negative non-decreasing…

Functional Analysis · Mathematics 2018-01-11 H. R. Moradi , M. E. Omidvar , K. Shebrawi

In this article, we prove that convex functions and log-convex functions obey certain general refinements that lead to several refinements and reverses of well known inequalities for matrices, including Young's inequality, Heinz inequality,…

Functional Analysis · Mathematics 2016-06-28 Mohammad Sababheh

For convex univalent functions we give instances where the sharp bound for various coefficient functionals are identical to those for the corresponding bound for the inverse function. We give instances where the sharp bounds differ and also…

Complex Variables · Mathematics 2022-12-12 Derek K. Thomas

We present a new lower bound for Euler's beta function, $B(x,y)$, which states that the inequality \begin{equation*} B(x,y)>\frac{x+y}{xy}\left(1-\frac{2xy}{x+y+1}\right) \end{equation*} holds on $(0,1]\times(0,1]$, which improves a lower…

Classical Analysis and ODEs · Mathematics 2023-05-05 Tiehong Zhao , Miaokun Wang

By considering a fixed point in unit disk $\Delta$, a new class of univalent convex functions is defined. Coefficient inequalities, integral operator and extreme points of this class are obtained.

Complex Variables · Mathematics 2009-04-23 Sh. Najafzadeh , M. Eshaghi Gordji , A. Ebadian

We investigate inexact proximity operators for weakly convex functions. To this aim, we derive sum rules for proximal {\epsilon}-subdifferentials, by incorporating the moduli of weak convexity of the functions into the respective formulas.…

Optimization and Control · Mathematics 2024-04-24 Ewa Bednarczuk , Giovanni Bruccola , Gabriele Scrivanti , The Hung Tran

The conic structure of the convex cone of non-negative operator convex functions on $(0,\infty)$ (also on $(-1,1)$) is clarified. We completely determine the extreme rays, the closed faces, and the simplicial closed faces of this convex…

Functional Analysis · Mathematics 2021-04-21 Uwe Franz , Fumio Hiai

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, we obtain a new class of functions, which is developed via the Hermite--Hadamard inequality for convex functions. The well-known one-one correspondence between the class of operator monotone functions and operator connections…

Functional Analysis · Mathematics 2021-07-23 R. Pal , M. Singh , M. S. Moslehian , J. S. Aujla

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

New proofs of the classical Hermite-Hadamard inequality are presented and several applications are given, including Hadamard-type inequalities for the functions, whose derivatives have inflection points or whose derivatives are convex.…

General Mathematics · Mathematics 2020-10-14 Ilham A. Aliev , Mehmet E. Tamar , Cagla Sekin

A real valued function $f$ defined on a convex $K$ is anemconvex function iff it satisfies $$ f((x+y)/2) \le (f(x)+f(y))/2 + 1. $$ A thorough study of approximately convex functions is made. The principal results are a sharp universal upper…

Metric Geometry · Mathematics 2007-05-23 S. J. Dilworth , Ralph Howard , James W. Roberts

We give an upper bound for the weighted geometric mean using the weighted arithmetic mean and the weighted harmonic mean. We also give a lower bound for the weighted geometric mean. These inequalities are proven for two invertible positive…

Functional Analysis · Mathematics 2014-10-21 Shigeru Furuichi

Our aim is to study the modular inequalities for some operators, for example the Bergman projection acting on, in Lebesgue spaces with variable exponent. Under proper assumptions on the variable exponent, we prove that the modular…

Complex Variables · Mathematics 2019-11-12 Mitsuo Izuki , Takahiro Noi , Yoshihiro Sawano

Let $\Omega$ be a pseudoconvex domain in $\mathbb C^n$ satisfying an $f$-property for some function $f$. We show that the Bergman metric associated to $\Omega$ has the lower bound $\tilde g(\delta_\Omega(z)^{-1})$ where $\delta_\Omega(z)$…

Complex Variables · Mathematics 2018-08-31 Dau The Phiet , Ninh Van Thu

We prove a condition on f \in C^2(\R+,\R) for the convexity of (f o det) on PSym(n), namely that f o det is convex on PSym(n) if and only if f"(s)+(n-1)/(ns) f'(s) >= 0 and f'(s)<= 0 \forall s \in \R+. This generalizes the observation that…

Mathematical Physics · Physics 2012-09-26 Stephan Lehmich , Patrizio Neff , Johannes Lankeit

In this paper, we obtain some new inequalities for ({\alpha},m)-convex functions. The analysis used in the proofs is fairly elementary and based on the use of Power-mean inequality.

Functional Analysis · Mathematics 2012-09-25 M. Emin Ozdemir , Merve Avci Ardic

In this paper, strongly $(\alpha,T)$-convex functions, i.e., functions $f:D\to \R$ satisfying the functional inequality $$ f(tx+(1-t)y)\leq tf(x)+(1-t)f(y)-t\alpha\big((1-t)(x-y)\big)-(1-t)\alpha\big(t(y-x)\big)$$ for $x,y\in D$ and $t\in…

Classical Analysis and ODEs · Mathematics 2012-12-06 Judit Makó , Kazimierz Nikodem , Zsolt Páles

The matrix convexity and the matrix monotony of a real $C^1$ function $f$ on $(0,\infty)$ are characterized in terms of the conditional negative or positive definiteness of the Loewner matrices associated with $f$, $tf(t)$, and $t^2f(t)$.…

Functional Analysis · Mathematics 2010-08-06 Fumio Hiai , Takashi Sano

It has been recently discovered that a convex function can be determined by its slopes and its infimum value, provided this latter is finite. The result was extended to nonconvex functions by replacing the infimum value by the set of all…

Functional Analysis · Mathematics 2025-10-21 Aris Daniilidis , David Salas , Sebastián Tapia-García