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Related papers: A Note Around Operator Bellman Inequality

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In this paper, we consider a modified version of Smirnov operator and obtain some Bernstein-type inequalities preserved by this operator. In particular, we prove some compact generalizations of the well-known inequalities of Bernstein,…

Complex Variables · Mathematics 2024-11-19 Ishfaq Ahmad Wani , Abdul Liman

We describe the Bellman function technique for proving sharp inequalities in harmonic analysis. To provide an example along with historical context, we present how it was originally used by Donald Burkholder to prove $L^p$ boundedness of…

Classical Analysis and ODEs · Mathematics 2018-05-29 Henry Riely

This paper is aimed to prove a quantitative estimate (in terms of the modulus of continuity) for the convergence in the nonlinear version of Korovkin's theorem for sequences of weakly nonlinear and monotone operators defined on spaces of…

Functional Analysis · Mathematics 2024-04-18 Sorin G. Gal , Constantin P. Niculescu

In this paper we introduce and study a new sequence of positive linear operators acting on function spaces defined on a convex compact subset. Their construction depends on a given Markov operator, a positive real number and a sequence of…

Functional Analysis · Mathematics 2017-10-18 Francesco Altomare , Mirella Cappelletti Montano , Vita Leonessa , Ioan Rasa

In this paper, we introduce a new sequence of operators based on the Gr\"unwald interpolation operators on Chebyshev nodes on the space $L^p[0,{\pi}]$. The operators we consider are integral variants of the Gr\"unwald interpolation…

Functional Analysis · Mathematics 2026-04-21 P. C. Vinaya

We enlarge the area of applicability of the Bellman function method to estimates in the spirit of the John--Nirenberg inequality abandoning certain convexity assumptions. As an application, we consider a characteristic of a function that is…

Classical Analysis and ODEs · Mathematics 2024-04-03 Egor Dobronravov , Dmitriy Stolyarov , Pavel Zatitskii

The Callebaut inequality says that \begin{align*} \sum_{ j=1}^n \left(A_j\sharp B_j\right)\leq \left(\sum_{ j=1}^n A_j \sigma B_j\right)\sharp\left(\sum_{ j=1}^n A_j \sigma^{\bot} B_j\right)\leq\left(\sum_{ j=1}^n A_j\right)\sharp…

Functional Analysis · Mathematics 2015-11-09 M. Bakherad , M. S. Moslehian

We prove in this note one weight norm inequalities for some positive Bergman-type operators.

Classical Analysis and ODEs · Mathematics 2019-02-26 Benoît F. Sehba

The present paper deals with modifications of Bernstein, Kantorovich, Durrmeyer and genuine Bernstein-Durrmeyer operators. Some previous results are improved in this study. Direct estimates for these operators by means of the first and…

Numerical Analysis · Mathematics 2018-10-23 Ana Maria Acu , Heiner Gonska

We extend an operator P\'{o}lya--Szeg\"{o} type inequality involving the operator geometric mean to any arbitrary operator mean under some mild conditions. Utilizing the Mond--Pe\v{c}ari\'c method, we present some other related operator…

Functional Analysis · Mathematics 2017-09-26 D. T. Hoa , M. S. Moslehian , C. Conde , P. Zhang

In this paper, we establish quantitative estimates for nonlinear sampling Kantorovich operators in terms of the modulus of continuity in the setting of Orlicz spaces. This general frame allows us to directly deduce some quantitative…

Functional Analysis · Mathematics 2021-02-18 Nursel Cetin , Danilo Costarelli , Gianluca Vinti

In this paper we obtain a new constant in the P\'{o}lya-Vinogradov inequality. Our argument follows previously established techniques which use the Fourier expansion of an interval to reduce to Gauss sums. Our improvement comes from…

Number Theory · Mathematics 2018-07-26 Bryce Kerr

The ostrowski inequality expresses bounds on the deviation of a function from its integral mean. The aim of this paper is to establish a new inequality using weight function which generalizes the inequalities of Dragomir, Wang and Cerone…

Classical Analysis and ODEs · Mathematics 2014-01-20 Ather Qayyum , Silvestru Sever Dragomir , Muhammad Shoaib , Muhammad Amir Latif

In this survey, we shall present characterizations of some distinguished classes of Hilbertian bounded linear operators (namely, normal operators, selfadjoint operators, and unitary operators) in terms of operator inequalities related to…

Functional Analysis · Mathematics 2020-07-03 Ameur Seddik

We compute the optimal constant for a generalized Hardy-Sobolev inequality, and using the product of two symmetrizations we present an elementary proof of the symmetries of some optimal functions. This inequality was motivated by a…

Analysis of PDEs · Mathematics 2007-05-23 S. Secchi , D. Smets , M. Willem

We consider the strong form of the John-Nirenberg inequality for the $L^2$-based BMO. We construct explicit Bellman functions for the inequality in the continuous and dyadic settings and obtain the sharp constant as well as the precise…

Classical Analysis and ODEs · Mathematics 2011-10-11 L. Slavin , V. Vasyunin

In this paper we derive Carleman estimates for the fractional relativistic operator. We consider changing-sign solutions to the heat equation for such operators. We prove monotonicity inequalities and convexity of certain energy functionals…

Analysis of PDEs · Mathematics 2022-01-27 Luz Roncal , Diana Stan , Luis Vega

In this note, we present a refinement of the well-known AM-GM inequality. We use this improved inequalty to establish corresponding inequalities on Hilbert space. We also give some refinements of the Kantorovich inequality.

Functional Analysis · Mathematics 2021-11-08 Mehdi Eghbali Amlashi , Mahmoud Hassani

In this article, we present a novel Carleman estimate for ultrahyperbolic operators, in $ \mathbb{R}^m_t \times \mathbb{R}^n_x $. Then, we use a special case of this estimate to obtain improved observability results for wave equations with…

Analysis of PDEs · Mathematics 2021-10-19 Vaibhav Kumar Jena

The aim of this paper is to construct a new expansion of $(1+1/x)^x$ related to Carleman's inequality. Our results extend some results of Yang [Approximations for constant e and their applications J. Math. Anal. Appl. 262 (2001) 651-659].

Classical Analysis and ODEs · Mathematics 2014-07-01 Cristinel Mortici , Yue Hu