English
Related papers

Related papers: Faces of quasidensity

200 papers

We investigate for a bounded semigroup of linear operators $S$ on a Banach space $E$ and a vector $x \in E$, when relative compactness of $S(I-T)x$ for every $T \in S$ implies relative compactness of the orbit $Sx$. In particular, we derive…

Functional Analysis · Mathematics 2020-07-03 Bálint Farkas , Henrik Kreidler

We present quasi-Banach spaces which are closely related to the duals of combinatorial Banach spaces. More precisely, for a compact family $\mathcal{F}$ of finite subsets of $\omega$ we define a quasi-norm $\lVert \cdot \rVert^\mathcal{F}$…

Functional Analysis · Mathematics 2025-01-22 Piotr Borodulin-Nadzieja , Sebastian Jachimek , Anna Pelczar-Barwacz

Arithmetic quasi-densities are a large family of real-valued set functions partially defined on the power set of $\mathbb{N}$, including the asymptotic density, the Banach density, the analytic density, etc. Let $B \subseteq \mathbb{N}$ be…

Number Theory · Mathematics 2024-05-22 Paolo Leonetti , Salvatore Tringali

In this paper, we unify the theory of SSD spaces, part of the theory of strongly representable multifunctions, and the theory of the equivalence of various classes of maximally monotone multifunctions.

Functional Analysis · Mathematics 2008-11-03 Stephen Simons

The correspondence between the class of nonexpansive mappings and the class of maximally monotone operators via the reflected resolvents of the latter has played an instrumental role in the convergence analysis of the splitting methods.…

Optimization and Control · Mathematics 2022-05-19 Leon Liu , Walaa M. Moursi , Jon Vanderwerff

Notion of frames and Bessel sequences for metric spaces have been introduced. This notion is related with the notion of Lipschitz free Banach spaces. \ It is proved that every separable metric space admits a metric $\mathcal{M}_d$-frame.…

Functional Analysis · Mathematics 2024-08-09 K. Mahesh Krishna

We give an overview of normality and conormality properties of pre-ordered Banach spaces. For pre-ordered Banach spaces $X$ and $Y$ with closed cones we investigate normality of $B(X,Y)$ in terms of normality and conormality of the…

Functional Analysis · Mathematics 2015-10-30 Miek Messerschmidt

This work deals with a maximal monotone operator $A$ of type (D) in a Banach space whose dual space is strictly convex. We establish some representations for the value $Ax$ at a given point $x$ via its values at nearby points of $x$. We…

Functional Analysis · Mathematics 2024-01-02 Nguyen B. Tran , Tran N. Nguyen , Huynh M. Hien

We study the set $\operatorname{MA}(X,Y)$ of operators between Banach spaces $X$ and $Y$ that attain their minimum norm, and the set $\operatorname{QMA}(X,Y)$ of operators that quasi attain their minimum norm. We characterize the…

Functional Analysis · Mathematics 2024-08-06 Domingo García , Manuel Maestre , Miguel Martín , Óscar Roldán , .

The main results of the paper: {\bf (1)} The dual Banach space $X^*$ contains a linear subspace $A\subset X^*$ such that the set $A^{(1)}$ of all limits of weak$^*$ convergent bounded nets in $A$ is a proper norm-dense subset of $X^*$ if…

Functional Analysis · Mathematics 2013-02-26 Mikhail I. Ostrovskii

A closed subspace of a Banach space $\cX$ is almost-invariant for a collection $\cS$ of bounded linear operators on $\cX$ if for each $T \in \cS$ there exists a finite-dimensional subspace $\cF_T$ of $\cX$ such that $T \cY \subseteq \cY +…

Functional Analysis · Mathematics 2012-04-23 Laurent W. Marcoux , Alexey I. Popov , Heydar Radjavi

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

We show that every maximally monotone operator of Fitzpatrick-Phelps type defined on a real Banach space must be of dense type. This provides an affirmative answer to a question posed by Stephen Simons in 2001 and implies that various…

Functional Analysis · Mathematics 2011-04-06 Heinz H. Bauschke , Jonathan M. Borwein , Xianfu Wang , Liangjin Yao

Chaotic linear dynamics deals primarily with various topological ergodic properties of semigroups of continuous linear operators acting on a topological vector space. We treat questions of characterizing which of the spaces from a given…

Functional Analysis · Mathematics 2008-10-22 S. Shkarin

Let $\mathcal{I,J}$ be symmetric quasi-Banach ideals of compact operators on an infinite-dimensional complex Hilbert space $H$, let $\mathcal{J:I}$ be a space of multipliers from $\mathcal{I}$ to $\mathcal{J}$. Obviously, ideals…

Operator Algebras · Mathematics 2012-04-23 A. F. Ber , V. I. Chilin , G. B. Levitina , F. A. Sukochev

We generalize the notion of Gelfand triples (also called Banach-Gelfand triples or rigged Hilbert spaces) by dropping the necessity of a continuous embedding. This means in our setting we lack of a chain inclusion. We replace the continuous…

Functional Analysis · Mathematics 2025-03-25 Nathanael Skrepek

We study monotone operators in reflexive Banach spaces that are invariant with respect to a group of suitable isometric isomorphisms and we show that they always admit a maximal extension which preserves the same invariance. A similar…

Functional Analysis · Mathematics 2025-02-19 Giulia Cavagnari , Giuseppe Savaré , Giacomo Enrico Sodini

We present a reflexive Banach space with an unconditional basis which is quasi-minimal and tight by range, i.e. of type (4) in Ferenczi-Rosendal list within the framework of Gowers' classification program of Banach spaces, but contrary to…

Functional Analysis · Mathematics 2013-04-01 A. Manoussakis , A. Pelczar-Barwacz

In this paper we present some new results on the existence of solutions of generalized variational inequalities in real reflexive Banach spaces with Fr\'echet differentiable norms. Moreover, we also give some theorems about the structure of…

Optimization and Control · Mathematics 2017-08-04 Nga Quynh Nguyen

Enlargements have proven to be useful tools for studying maximally monotone mappings. It is therefore natural to ask in which cases the enlargement does not change the original mapping. Svaiter has recently characterized non-enlargeable…

Functional Analysis · Mathematics 2011-10-17 Jonathan M. Borwein , Regina Burachik , Liangjin Yao