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Related papers: A generalised mid summability in Banach spaces

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For a Banach space X we define RUMD_n(X) to be the infimum of all c>0 such that (AVE_{\epsilon_k =\pm 1} || \sum_1^n epsilon_k (M_k - M_{k-1} )||_{L_2^X}^2 )^{1/2} <= c || M_n ||_{L_2^X} holds for all Walsh-Paley martingales {M_k}_0^n…

Functional Analysis · Mathematics 2008-02-03 Stefan Geiss

In this paper we study shorted operators relative to two different subspaces, for bounded operators on infinite dimensional Hilbert spaces. We define two notions of complementability in the sense of Ando for operators, and study the…

Functional Analysis · Mathematics 2007-05-23 Jorge Antezana , Gustavo Corach , Demetrio Stojanoff

We consider the action of finitely truncated singular integral operators on functions taking values in a Banach space. Such operators are bounded for any Banach space, but we show a quantitative improvement over the trivial bound in any…

Functional Analysis · Mathematics 2023-10-16 Tuomas Hytönen

The notion of mid $p$-summable sequences was introduced by Karn and Sinha in 2014 and recently explored and expanded by Botelho, Campos and Santos in 2017. In this paper we design a theory of mid summable sequences in the anisotropic…

Functional Analysis · Mathematics 2018-03-06 Jamilson R. Campos , Joedson Santos

In this paper we completely characterize the norm attainment set of a bounded linear operator on a Hilbert space. This partially answers a question raised recently in [\textit{D. Sain, On the norm attainment set of a bounded linear…

Functional Analysis · Mathematics 2019-03-20 Debmalya Sain

The aim of this note is to complement and extend some recent results on Whitley's indices of thinness and thickness in three main directions. Firstly, we investigate both the indices when forming $\ell_p$-sums of Banach spaces, and obtain…

Functional Analysis · Mathematics 2014-05-28 Trond A. Abrahamsen , Johann Langemets , Vegard Lima , Olav Nygaard

We consider real spaces only. Definition. An operator $T:X\to Y$ between Banach spaces $X$ and $Y$ is called a Hahn-Banach operator if for every isometric embedding of the space $X$ into a Banach space $Z$ there exists a norm-preserving…

Functional Analysis · Mathematics 2007-05-23 M. I. Ostrovskii

The use of a tensor product perspective has enriched functional analysis and other important areas of mathematics and physics. The context of operator spaces is clearly no exception. The aim of this manuscript is to kick off the development…

Operator Algebras · Mathematics 2023-02-09 Alejandro Chávez-Domínguez , Verónica Dimant , Daniel Galicer

A bounded linear operator $T$ on a Banach space $X$ is called subspace-hypercyclic if there is a subspace $M \subsetneq X$ and a vector $x \in X$ such that $orb{(x,T)} \cap M$ is dense in $M$. We show that every Banach space supports…

Functional Analysis · Mathematics 2019-12-30 A. Augusto , L. Pellegrini

The theory of Banach spaces of Dirichlet series has drawn an increasing attention in the recent 25 years. One of the main interest of this new theory is that of defining analogues of the classical spaces of analytic functions on the unit…

Complex Variables · Mathematics 2024-03-12 Carlos Gómez-Cabello , Pascal Lefèvre , Hervé Queffélec

We introduce a new type of norm for ordered vector spaces majorized by a proper (convex) cone that generalizes the notions of order unit norm and base norm. Then we give sufficient conditions to ensure its completeness. In the case of…

Functional Analysis · Mathematics 2022-01-07 Vasco Schiavo

We develop a general theory of multilinear singular integrals with operator-valued kernels, acting on tuples of UMD Banach spaces. This, in particular, involves investigating multilinear variants of the $\mathcal R$-boundedness condition…

Classical Analysis and ODEs · Mathematics 2020-06-02 Francesco Di Plinio , Kangwei Li , Henri Martikainen , Emil Vuorinen

We modify the very well known theory of normed spaces $(E, \norm)$ within functional analysis by considering a sequence $(\norm_n : n\in\N)$ of norms, where $\norm_n$ is defined on the product space $E^n$ for each $n\in\N$. Our theory is…

Functional Analysis · Mathematics 2012-03-20 H. G. Dales , M. E. Polyakov

We show that the lower limit of a sequence of maximal monotone operators on a reflexive Banach space is a representable monotone operator. As a consequence, we obtain that the variational sum of maximal monotone operators and the…

Optimization and Control · Mathematics 2011-01-31 Yboon García , Marc Lassonde

Given a set $B$ of operators between subspaces of $L_p$ spaces, we characterize the operators between subspaces of $L_p$ spaces that remain bounded on the $X$-valued $L_p$ space for every Banach space on which elements of the original class…

Functional Analysis · Mathematics 2021-03-10 Mikael de la Salle

Let $X$ be a Banach space and $(\Omega,\Sigma)$ be a measure space. We provide a characterization of sequences in the space of $X$-valued countably additive measures on $\Omega,\Sigma)$ of bounded variation that generate complemented copies…

Functional Analysis · Mathematics 2016-09-06 Narcisse Randrianantoanina

We present a denotational semantics for higher-order probabilistic programs in terms of linear operators between Banach spaces. Our semantics is rooted in the classical theory of Banach spaces and their tensor products, but bears…

Logic in Computer Science · Computer Science 2019-03-01 Fredrik Dahlqvist , Dexter Kozen

Let B be a p-uniformly convex Banach space, with p >= 2. Let T be a linear operator on B, and let A_n x denote the ergodic average (1 / n) sum_{i< n} T^n x. We prove the following variational inequality in the case where T is power bounded…

Dynamical Systems · Mathematics 2015-05-20 Jeremy Avigad , Jason Rute

The article presents a new method of integration of functions with values in Banach spaces. This integral and related notions prove to be a useful tool in the study of Banach space geomtry.

Functional Analysis · Mathematics 2007-05-23 V Kadets , B. Shumyatskiy , R. Shvidkoy , L. Tseytlin , K. Zheltukhin

An L-embedded Banach spaace is a Banach space which is complemented in its bidual such that the norm is additive between the two complementary parts. On such spaces we define a topology, called an abstract measure topology, which by known…

Functional Analysis · Mathematics 2015-05-14 Hermann Pfitzner