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Related papers: Jensen's inequality for conditional expectations

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We give an extension of Hua's inequality in pre-Hilbert $C^*$-modules without using convexity or the classical Hua's inequality. As a consequence, some known and new generalizations of this inequality are deduced. Providing a Jensen…

Operator Algebras · Mathematics 2010-05-31 Mohammad Sal Moslehian

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

We propose a list of inequalities which characterize central elements in von Neumann algebras and C*-algebras.

Operator Algebras · Mathematics 2020-10-21 Andrej Novikov , Oleg Tikhonov

In this paper we consider the order-like relation for self-adjoint operators on some Hilbert space. This relation is defined by using Jensen inequality. We will show that under some assumptions this relation is antisymmetric.

Functional Analysis · Mathematics 2009-04-17 Tomohiro Hayashi

Let $I$ and $J$ be two intervals, and let $f, g: I \rightarrow \mathbb{R}$. If for any points $a$ and $b$ in $I$ and any positive numbers $p$ and $q$ such that $p + q = 1$, we have \begin{align} \nonumber p f(a) + q f(b) + g(pa + qb) \in J,…

General Mathematics · Mathematics 2023-01-13 Jun Liu

In this paper we point out a converse result of the celebrated Jensen inequality for differentiable convex mappings of several variables and apply it to counterpart well-known analytic inequalities. Applications to Shannon's and Renyi's…

Classical Analysis and ODEs · Mathematics 2007-05-23 Sever Silvestru Dragomir

We study the Jensen functional equations on a group $G$ with values in an abelian group $H$: \begin{align} \tag{J1}\label{eq:J1} f(xy)+f(xy^{-1})&=2f(x)\qquad(\forall\,x,y\in G),\\ \tag{J2}\label{eq:J2}…

Group Theory · Mathematics 2025-11-18 Dang Vo Phuc

This is a continuation of our previous paper. We consider a certain order-like relation for positive operators on a Hilbert space. This relation is defined by using the Jensen inequality with respect to the square-root function. We show…

Functional Analysis · Mathematics 2012-03-07 Tomohiro Hayashi

In this paper, by using the representation theorem for sublinear expectations, we give a simple proof to obtain two inequalities about the sample mean for independent random vectors under sublinear expectations.

Probability · Mathematics 2024-10-16 Xiaojuan Li , Mingshang Hu

A generalization of Powers-St$\o$rmer's inequality for operator monotone functions on $[0, +\infty)$ and for positive linear functional on general $C^*$-algebras will be proved. It also will be shown that the generalized Powers-St$\o$rmer…

Operator Algebras · Mathematics 2012-05-01 Dinh Trung Hoa , Hiroyuki Osaka , Ho Minh Toan

After an elementary derivation of Bell's inequality, several forms of expectation functions for two-valued observables are discussed. Special emphasis is given to hypothetical stronger-than quantum expectation functions which give rise to a…

Quantum Physics · Physics 2016-09-08 Kurt Krenn , Karl Svozil

We extend Dragomir's refinement of Jensen's inequality from the dicrete to the general case, identifying the equality conditions.

Classical Analysis and ODEs · Mathematics 2011-02-22 J. M. Aldaz

We establish several deep existence criteria for conditional expectations on von Neumann algebras, and then apply this theory to develop a noncommutative theory of representing measures of characters of a function algebra. Our main cycle of…

Operator Algebras · Mathematics 2021-10-07 David P. Blecher , Louis E. Labuschagne

We construct a weak conditional expectation from the section C*-algebra of a Fell bundle over a unital inverse semigroup to its unit fibre. We use this to define the reduced C*-algebra of the Fell bundle. We study when the reduced…

Operator Algebras · Mathematics 2019-04-30 Alcides Buss , Ruy Exel , Ralf Meyer

In this paper we establish the Ulam stability of Jensen functional inequality in some classes of groups.

Functional Analysis · Mathematics 2020-10-13 Gang Lu , Lulu Qu , Yuanfeng Jin , Choonkil Park

We give a number of equivalent conditions (including weak centrality) for a general $C^*$-algebra to have the centre-quotient property. We show that every $C^*$-algebra $A$ has a largest weakly central ideal $J_{wc}(A)$. For an ideal $I$ of…

Operator Algebras · Mathematics 2020-10-14 Robert J. Archbold , Ilja Gogić

We generalize the well-known mean value inequality of subharmonic functions for a slightly more general function class. We also apply this generalized mean value inequality to weighted boundary behavior and nonintegrability questions of…

Classical Analysis and ODEs · Mathematics 2007-05-23 Juhani Riihentaus

Consider a stationary real-valued time series $\{X_n\}_{n=0}^{\infty}$ with a priori unknown distribution. The goal is to estimate the conditional expectation $E(X_{n+1}|X_0,..., X_n)$ based on the observations $(X_0,..., X_n)$ in a…

Probability · Mathematics 2008-06-19 Gusztav Morvai , Benjamin Weiss

We study the Mercer inequality and its operator extension for superquadratic functions. In particular, we give a more general form of the Mercer inequality by replacing some constants by positive operators. As some consequences, our results…

Functional Analysis · Mathematics 2024-03-27 Mohsen Kian , Zainab Peymani Mazraj

A necessary and sufficient condition on a sequence $\{\mathfrak{A}_n\}_{n\in \mathbb{N}}$ of $\sigma$-subalgebras that assures convergence almost every where of conditional expectations is given.

Probability · Mathematics 2023-01-23 Alberto Alonso , Fernando Brambila-Paz