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Related papers: A Nonlinear Extension of Korovkin's Theorem

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A simple version for the extension of the Taylor theorem to the operator functions was found. The expansion was done with respect to a value given by a diagonal matrix for the non-commutative case, and the coefficients are given both by…

Mathematical Physics · Physics 2007-05-23 Ioan Sturzu

We introduce a new fixed point theorem of Krasnoselskii type for discontinuous operators. As an application we use it to study the existence of positive solutions of a second-order differential problem with separated boundary conditions and…

Classical Analysis and ODEs · Mathematics 2017-03-14 Rubén Figueroa , Rodrigo López Pouso , Jorge Rodríguez-López

We construct nonlinear extensions of Dirac's relativistic electron equation that preserve its other desirable properties such as locality, separability, conservation of probability and Poincar\'e invariance. We determine the constraints…

High Energy Physics - Theory · Physics 2009-02-27 Wei-Khim Ng , Rajesh R. Parwani

Given a compact of ${\bf R}^n$, there is always a doubling measure having it as its support. We use this fact to construct an integral operator that extends differentiable functions defined on any compact set of ${\bf R}^n$ to the whole of…

Classical Analysis and ODEs · Mathematics 2007-05-23 Jaume Gudayol

We introduce a~\textit{Choquet-Sugeno-like operator} generalizing many operators for bounded functions and monotone measures from the literature, e.g., Sugeno-like operator, Lov\'{a}sz and Owen measure extensions, $\rF$-decomposition…

Functional Analysis · Mathematics 2021-02-02 Michal Boczek , Ondrej Hutník , Marek Kaluszka

In this article we generalize Cobham theorem to a large class of substitutions including non primitive and non constant length substitutions.

Combinatorics · Mathematics 2008-01-08 Fabien Durand

In this paper, using the concept of $A$-statistical convergence which is a regular (non-matrix) summability method, we obtain a general Korovkin type approximation theorem which concerns the problem of approximating a function $f$ by means…

Classical Analysis and ODEs · Mathematics 2007-05-23 Esra Erkus , Oktay Duman

We establish a dilation-theoretic characterization of the Choquet order on the space of measures on a compact convex set using ideas from the theory of operator algebras. This yields an extension of Cartier's dilation theorem to the…

Operator Algebras · Mathematics 2021-05-03 Kenneth R. Davidson , Matthew Kennedy

We present Korovkin approximation theorems that incorporate summability methods. These result allows us to obtain a unified treatment of several previous results, focusing on the underlying structure and the properties that a summability…

Functional Analysis · Mathematics 2023-07-07 M. del Carmen Listán-García , María Pilar Romero de la Rosa

We obtain smoothing estimates for certain nonlinear convolution operators on prime fields, leading to quantitative nonlinear Roth type theorems. Compared with the usual linear setting (i.e. arithmetic progressions), the nonlinear nature of…

Number Theory · Mathematics 2016-08-22 Jean Bourgain , Mei-Chu Chang

In this paper we develop a capacities theory connected with the fractional Sobolev spaces with variable exponents. Two kinds of capacities are studied: Sobolev capacity and relative capacity. Basic properties of capacities, including…

Functional Analysis · Mathematics 2024-10-15 Azeddine Baalal , Mohamed Berghout

In this note we develop a framework which allows to prove an existence result for non-linear evolution problems involving time-dependent, pseudo-monotone operators. This abstract existence result is applicable to a large class of concrete…

Analysis of PDEs · Mathematics 2019-11-22 Alex Kaltenbach , Michael Růžička

If $Au=-div(a(x,Du))$ is a monotone operator defined on the Sobolev space $W^{1,p}(R^n)$, $1<p<+\infty$, with $a(x,0)=0$ for a.e. $x\in R^n$, the capacity $C_A(E,F)$ relative to $A$ can be defined for every pair $(E,F)$ of bounded sets in…

funct-an · Mathematics 2008-02-03 G. Dal Maso , I. V. Skrypnik

We adapt a nonlinear version of Peetre's theorem on local operators in order to investigate representatives of nonlinear generalized functions occurring in the theory of full Colombeau algebras.

Functional Analysis · Mathematics 2017-04-04 Eduard A. Nigsch

We provide extension procedures for nonlinear expectations to the space of all bounded measurable functions. We first discuss a maximal extension for convex expectations which have a representation in terms of finitely additive measures.…

Probability · Mathematics 2018-07-18 Robert Denk , Michael Kupper , Max Nendel

The goal of this paper is to sketch a broader outline of the mathematical structures present in the Nonlinear Maxwell Theory in continuation of work presented in my previous articles. In particular, I display new types of both dynamic and…

General Physics · Physics 2007-05-23 Artur Sowa

Real linear operators emerge in a range of mathematical physics applications. In this paper spectral questions of compact real linear operators are addressed. A Lomonosov-type invariant subspace theorem for antilinear compact operators is…

Spectral Theory · Mathematics 2013-03-28 Santtu Ruotsalainen

The classical Korovkin theorem traditionally relies on the positivity of the underlying sequence of operators. However, in 1968, D. E. Wulbert established the first non-positive version. In this article, we generalize Wulbert's result to…

Functional Analysis · Mathematics 2025-09-19 V. B. Kiran Kumar , M. N. N. Namboodiri , P. C. Vinaya

This is an expository paper discussing various versions of Khovanov homology theories, interrelations between them, their properties, and their applications to other areas of knot theory and low-dimensional topology.

Geometric Topology · Mathematics 2011-01-31 Alexander Shumakovitch

The addition relation for the Riemann theta functions and for its limits, which lead to the appearance of exponential functions in soliton type equations is discussed. The presented form of addition property resolves itself to the…

Exactly Solvable and Integrable Systems · Physics 2009-11-07 J. A. Zagrodzinski , T. Nikiciuk