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Related papers: Approximate identities for Ideals in $L(L^p))$

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In a previous paper the second author introduced a compact topology on the space of closed ideals of a unital Banach algebra A. If A is separable then this topology is either metrizable or else neither Hausdorff nor first countable. Here it…

Functional Analysis · Mathematics 2007-05-23 J. F. Feinstein , D. W. B. Somerset

We show that a representation of a Banach algebra $A$ on a Banach space $X$ can be extended to a canonical representation of $A^{**}$ on $X$ if and only if certain orbit maps $A\to X$ are weakly compact. When this is the case, we show that…

Functional Analysis · Mathematics 2018-03-26 Eusebio Gardella , Hannes Thiel

Fixed a Banach operator ideal $\mathcal A$, we introduce and investigate two new approximation properties, which are strictly weaker than the bounded approximation property (BAP) for $\mathcal A$ of Lima, Lima and Oja (2010). We call them…

Functional Analysis · Mathematics 2015-08-10 Silvia Lassalle , Eve Oja , Pablo Turco

It is well known that weakly $p$-summable sequences in a Banach space $E$ are associated to bounded operators from $\ell_{p^*}$ to $E$, and unconditionally $p$-summable sequences in $E$ are associated to compact operators from $\ell_{p^*}$…

Functional Analysis · Mathematics 2024-03-07 Geraldo Botelho , Ariel S. Santiago

We introduce the notions of almost Lipschitz embeddability and nearly isometric embeddability. We prove that for $p\in [1,\infty]$, every proper subset of $L_p$ is almost Lipschitzly embeddable into a Banach space $X$ if and only if $X$…

Metric Geometry · Mathematics 2017-09-27 Florent Baudier , Gilles Lancien

We investigate topologically left Noetherian Banach algebras. We show that if $G$ is a compact group, then $L^{\, 1}(G)$ is topologically left Noetherian if and only if $G$ is metrisable. We prove that, given a Banach space $E$ such that…

Functional Analysis · Mathematics 2019-02-27 Jared T. White

In the framework of operator theory, we investigate a close Lie theoretic relationship between all operator ideals and certain classical groups of invertible operators that can be described as the solution sets of certain algebraic…

Operator Algebras · Mathematics 2013-03-21 Daniel Beltita , Sasmita Patnaik , Gary Weiss

We address the following two questions regarding the maximal left ideals of the Banach algebra $\mathscr{B}(E)$ of bounded operators acting on an infinite-dimensional Banach pace $E$: (Q1) Does $\mathscr{B}(E)$ always contain a maximal left…

Functional Analysis · Mathematics 2014-11-26 H. G. Dales , Tomasz Kania , Tomasz Kochanek , Piotr Koszmider , Niels Jakob Laustsen

In this article, we prove the proximinality of closed unit ball of $M$-ideals of compact operators. We also prove the ball proximinality of $M$-embedded spaces in their biduals. Moreover, we show that $\mathcal{K}(\ell_1)$, the space of…

Functional Analysis · Mathematics 2020-08-18 C. R. Jayanarayanan , Sreejith Siju

We give several applications of a recent theorem of the second author, which solved a conjecture of the first author with Hay and Neal, concerning contractive approximate identities; and another of Hay from the theory of noncommutative peak…

Operator Algebras · Mathematics 2011-02-22 David P. Blecher , Charles John Read

This paper may be viewed as having two aims. First, we continue our study of algebras of operators on a Hilbert space which have a contractive approximate identity, this time from a more Banach algebraic point of view. Namely, we mainly…

Operator Algebras · Mathematics 2012-06-20 Melahat Almus , David P. Blecher , Charles John Read

Let $A$ be a Banach algebra and $I$ a dense ideal in $A$. A natural question in the theory of operator algebras is whether the property that all derivations $D: A \to I$ are inner (implemented by elements in $I$) implies that all…

Functional Analysis · Mathematics 2026-03-17 Hamid Shafieasl , Amir Mohammad Tavakkoli

This paper studies approximation properties of linear sampling operators in general Banach lattices $X$. We obtain matching direct and inverse approximation estimates, convergence criteria, equivalence results involving special…

Functional Analysis · Mathematics 2026-01-28 Yurii Kolomoitsev

We study a notion analogous to the $p$-Approximation Property ($p$-AP) for Banach spaces, within the noncommutative context of operator spaces. Referred to as the $p$-Operator Approximation Property ($p$-OAP), this concept is linked to the…

Functional Analysis · Mathematics 2025-06-09 Javier Alejandro Chávez-Domínguez , Verónica Dimant , Daniel Galicer

We show that a positive operator between $L^p$-spaces is given by integration against a kernel function if and only if the image of each positive function has a lower semi-continuous representative with respect to a suitable topology. This…

Functional Analysis · Mathematics 2024-06-11 Moritz Gerlach , Jochen Glück

The aim of this paper is to study $L^p$-boundedness property of the pseudo differential operator associated with a symbol, on rank one Riemannian symmetric spaces of noncompact type, where the symbol satisfies H\"ormander-type conditions…

Classical Analysis and ODEs · Mathematics 2022-04-27 Sanjoy Pusti , Tapendu Rana

It has been established by Inoue that a complex locally C*-algebra with a dense ideal posesses a bounded approximate identity which belonges to that ideal. It has been shown by Fritzsche that if a unital complex locally C*-algebra has an…

Operator Algebras · Mathematics 2008-09-02 Alexander A. Katz , Oleg Friedman

A left ideal of any C*-algebra is an example of an operator algebra with a right contractive approximate identity (r.c.a.i.). Conversely, we show here and in a `pre-quel' to this paper [B], that operator algebras with r.c.a.i. should be…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Masayoshi Kaneda

For $p\in [1,\infty)$, we show that every unital $L^p$-operator algebra contains a unique maximal $C^*$-subalgebra, which is always abelian if $p\neq 2$. Using this, we canonically associate to every unital $L^p$-operator algebra $A$ an…

Operator Algebras · Mathematics 2024-09-06 Yemon Choi , Eusebio Gardella , Hannes Thiel

For a Banach algebra A and a closed ideal I, the notion of bounded approximate diagonal modulo I has been studied and investigated. In this paper we define the notion of locally bounded approximate diagonal modulo an ideal I for a Frechet…

Functional Analysis · Mathematics 2019-01-11 Somayeh Rahnama , Ali Rejali