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Related papers: A stand-alone analysis of quasidensity

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As objects of study in functional analysis, Hilbert spaces stand out as special objects of study as do nuclear spaces in view of a rich geometrical structure they possess as Banach and Frechet spaces, respectively. On the other hand, there…

Functional Analysis · Mathematics 2013-10-29 M A Sofi

Recently introduced by the authors in [Proc. Edinb. Math. Soc. 60 (2020), 139-167], quasi-densities form a large family of real-valued functions partially defined on the power set of the integers that serve as a unifying framework for the…

Number Theory · Mathematics 2022-11-10 Paolo Leonetti , Salvatore Tringali

In this paper we give various characterizations of quasiopen sets and quasicontinuous functions on metric spaces. For complete metric spaces equipped with a doubling measure supporting a p-Poincar\'e inequality we show that quasiopen and…

Functional Analysis · Mathematics 2017-02-13 Anders Björn , Jana Björn , Jan Malý

We prove that if f : R^N --> R is quasiconvex and U is open in the density topology of R^N, then sup_U f = ess sup_U f, while inf_U f = ess inf_U f if and only if the equality holds when U = R^N. The first (second) property is typical of…

Metric Geometry · Mathematics 2019-08-15 Patrick J. Rabier

Let $E$ be a Sidon subset of the integers and suppose $X$ is a Banach space. Then Pisier has shown that $E$-spectral polynomials with values in $X$ behave like Rademacher sums with respect to $L_p-$norms. We consider the situation when $X$…

Functional Analysis · Mathematics 2009-09-25 Nigel J. Kalton

Nearly convex sets play important roles in convex analysis, optimization and theory of monotone operators. We give a systematic study of nearly convex sets, and construct examples of subdifferentials of lower semicontinuous convex functions…

Optimization and Control · Mathematics 2015-07-28 Sarah M. Moffat , Walaa M. Moursi , Xianfu Wang

Quasimetric spaces form a natural framework to study distance problems with an inherent directional asymmetry. We introduce a simple novel class of quasimetrics on probability simplices, inspired by the Chebyshev distance. It is shown that…

Metric Geometry · Mathematics 2025-11-03 Michał Eckstein , Tomasz Miller , Karol Życzkowski

This paper is aimed to show the essential role played by the theory of quasi-analytic functions in the study of the determinacy of the moment problem on finite and infinite-dimensional spaces. In particular, the quasi-analytic criterion of…

Functional Analysis · Mathematics 2016-12-21 Maria Infusino

We investigate certain envelopes of open sets in dual Banach spaces which are related to extending holomorphic functions. We give a variety of examples of absolutely convex sets showing that the extension is in many cases not possible. We…

Functional Analysis · Mathematics 2010-05-10 D. Garcia , O. F. K. Kalenda , M. Maestre

This paper explores the interactions of absolute continuity of the (quasi)norm with the concepts that are fundamental in the theory of rearrangement-invariant (quasi-)Banach function spaces, such as the Luxemburg representation or the…

Functional Analysis · Mathematics 2025-10-15 Dalimil Peša

A class of translation-invariant Banach spaces of quasianalytic ultradistributions is introduced and studied. They are Banach modules over a Beurling algebra. Based on this class of Banach spaces, we define corresponding test function…

Functional Analysis · Mathematics 2015-07-28 Pavel Dimovski , Bojan Prangoski , Jasson Vindas

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

This paper is about certain linear subspaces of Banach SN spaces (that is to say Banach spaces which have a symmetric nonexpansive linear map into their dual spaces). We apply our results to monotone linear subspaces of the product of a…

Functional Analysis · Mathematics 2013-06-26 Stephen Simons

In a series of previous papers, we initiated a systematic study of semihypergroups and had a thorough discussion on certain analytic and algebraic aspects associated to this class of objects. In particular, we introduced the notion of…

Functional Analysis · Mathematics 2024-04-30 Choiti Bandyopadhyay

One of the important consequences of the Banach Fixed Point Theorem is Hutchinson's theorem which states the existence and uniqueness of fractals in complete metric spaces. The aim of this paper is to extend this theorem for semimetric…

Dynamical Systems · Mathematics 2021-12-01 Mátyás Kocsis , Zsolt Páles

In contrast to classical strongly continuous semigroups, the study of bi-continuous semigroups comes with some freedom in the properties of the associated locally convex topology. This paper aims to give minimal assumptions in order to…

Functional Analysis · Mathematics 2023-07-19 Karsten Kruse , Felix L. Schwenninger

We investigate geometric properties of a metric measure space where every function in the Newton--Sobolev space $N^{1,\infty}(Z)$ has a Lipschitz representative. We prove that when the metric space is locally complete and the reference…

Metric Geometry · Mathematics 2025-09-03 Miguel García-Bravo , Toni Ikonen , Zheng Zhu

The subject is the overview of the use of quasi-entropy in finite dimensional spaces. Matrix monotone functions and relative modular operators are used. The origin is the relative entropy and the f-divergence, monotone metrics, covariance…

Quantum Physics · Physics 2010-09-15 Denes Petz

We study quasi-modular pseudometric spaces as asymmetric refinements of modular metric structures. To each such space we associate canonical forward and backward quasi-uniformities and the corresponding directional topologies. We introduce…

General Topology · Mathematics 2026-02-03 Philani Rodney Majozi

We study the quasiadditivity property (a version of superadditivity with a multiplicative constant) of variational capacity in metric spaces with respect to Whitney type covers. We characterize this property in terms of a Mazya type…

Functional Analysis · Mathematics 2015-12-23 Juha Lehrbäck , Nageswari Shanmugalingam