Results 41 to 50 of about 513,254 (163)

Amenability Constants for Unconditional Sums of Banach Algebras

Mathematische Nachrichten, Volume 299, Issue 9, Page 2472-2494, September 2026.
ABSTRACT We study Johnson amenability for unconditional direct sums of Banach algebras. Given a family (Ai)i∈I$(A_i)_{i\in I}$ of Banach algebras and a Banach sequence lattice E$E$ on I$I$, the E$E$‐sum ⨁i∈IAiE${\bigl (\bigoplus _{i\in I} A_i\bigr)}_{\!E}$ carries a natural Banach algebra structure via coordinatewise multiplication.
Tomasz Kania, Jerzy Ka̧kol
wiley   +1 more source

Null projections and noncommutative function theory in operator algebras

Journal of the London Mathematical Society, Volume 114, Issue 1, July 2026.
Abstract We study projections in the bidual of a C∗$\mathrm{C}^*$‐algebra B$B$ that are null with respect to a subalgebra A$A$, that is, projections p∈B∗∗$p\in B^{**}$ satisfying |φ|(p)=0$|\varphi |(p)=0$ for every φ∈B∗$\varphi \in B^*$ annihilating A$A$. In the separable case, A$A$‐null projections are precisely the peak projections in the bidual of A$
David P. Blecher, Raphaël Clouâtre
wiley   +1 more source

KKM implies Hahn-Banach

Results in Nonlinear Analysis, 2019
Our title means that the Knaster-Kuratowski Mazurkiewicz theorem in 1929 implies the Hahn-Banach theorem. This theorem originated from Hahn in 1926 and Banach in 1929 is of basic importance in the analysis of problems concerning the existence of ...
Sehie Park
doaj  

Spaces generated by the cone of sublinear operators

Karpatsʹkì Matematičnì Publìkacìï, 2018
This paper deals with a study on classes of non linear operators. Let $SL(X,Y)$ be the set of all sublinear operators between two Riesz spaces $X$ and $Y$. It is a convex cone of the space $H(X,Y)$ of all positively homogeneous operators.
A. Slimane
doaj   +1 more source

Identification and Estimation of Large Network Games with Private Link Information

International Economic Review, Volume 67, Issue 2, Page 411-432, May 2026.
ABSTRACT We study the identification and estimation of large network games in which individuals choose continuous actions while holding private information about their links and payoffs. Extending the framework of Galeotti et al., we build a tractable empirical model of such network games and show that the parameters in individual payoffs are ...
Hülya Eraslan, Xun Tang
wiley   +1 more source

Quantitative Hahn-Banach Theorems and Isometric Extensions forWavelet and Other Banach Spaces

Axioms, 2013
We introduce and study Clarkson, Dol’nikov-Pichugov, Jacobi and mutual diameter constants reflecting the geometry of a Banach space and Clarkson, Jacobi and Pichugov classes of Banach spaces and their relations with James, self-Jung, Kottman and Schäffer
Sergey Ajiev
doaj   +1 more source

Potential trace inequalities via a Calderón‐type theorem

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract In this paper, we develop a general theoretical tool for the establishment of the boundedness of notoriously difficult operators (such as potentials) on certain specific types of rearrangement‐invariant function spaces from analogous properties of operators that are easier to handle (such as fractional maximal operators).
Zdeněk Mihula, Luboš Pick, Daniel Spector   +2 more
wiley   +1 more source

Solvability of invariant systems of differential equations on H2$\mathbb {H}^2$ and beyond

Mathematische Nachrichten, Volume 299, Issue 2, Page 456-479, February 2026.
Abstract We show how the Fourier transform for distributional sections of vector bundles over symmetric spaces of non‐compact type G/K$G/K$ can be used for questions of solvability of systems of invariant differential equations in analogy to Hörmander's proof of the Ehrenpreis–Malgrange theorem.
Martin Olbrich, Guendalina Palmirotta
wiley   +1 more source

Approximation numbers of an infinite matrix on HpB spaces [PDF]

Egyptian Journal of Pure and Applied Science
In this paper, we study conditions that an infinite matrix has to satisfy in order to define a linear bounded operator from any weighted HpB space[1] with a weighted sequence of positive numbers into itself, and give upper and lower estimations of the ...
Nashat Faried, Hany El Deeb
doaj   +1 more source

A Choquet theory of Lipschitz‐free spaces

Proceedings of the London Mathematical Society, Volume 132, Issue 2, February 2026.
Abstract Let (M,d)$(M,d)$ be a complete metric space and let F(M)$\mathcal {F}({M})$ denote the Lipschitz‐free space over M$M$. We develop a ‘Choquet theory of Lipschitz‐free spaces’ that draws from the classical Choquet theory and the De Leeuw representation of elements of F(M)$\mathcal {F}({M})$ (and its bi‐dual) by positive Radon measures on βM ...
Richard J. Smith
wiley   +1 more source