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Related papers: Generalized projections on general Banach spaces

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There are numerous cases of discrepancies between results obtained in the setting of real Banach spaces and those obtained in the complex context. This article is a modern exposition of the subtle differences between key results and…

Functional Analysis · Mathematics 2022-02-25 M. S. Moslehian , G. A. Muñoz-Fernández , A. M. Peralta , J. B. Seoane-Sepúlveda

In this paper, we introduced two new generalized metric spaces called partial b_{v}(s) and b_{v}({\theta}) metric spaces which extend b_{v}(s) metric space, b-metric space, rectangular metric space, v-generalized metric space, partial…

General Topology · Mathematics 2023-01-27 Ibrahim Karahan , Irfan Isik

Non-trivial examples of generalized paracomplex structures (in the sense of the generalized geometry \`a la Hitchin) are constructed applying the twistor space construction scheme.

Differential Geometry · Mathematics 2024-09-10 Johann Davidov

We construct a locally finite graph and a bounded geometry metric space which do not admit a quasi-isometric embedding into any uniformly convex Banach space. Connections with the geometry of $c_0$ and superreflexivity are discussed.

Metric Geometry · Mathematics 2015-01-29 Piotr W. Nowak

Inspired by some recent development on the theory about projection valued dilations for operator valued measures or more generally bounded homomorphism dilations for bounded linear maps on Banach algebras, we explore a pure algebraic…

Operator Algebras · Mathematics 2015-04-28 Deguang Han , David R. Larson , Bei Liu , Rui Liu

Geometric quantiles are location parameters which extend classical univariate quantiles to normed spaces (possibly infinite-dimensional) and which include the geometric median as a special case. The infinite-dimensional setting is highly…

Statistics Theory · Mathematics 2026-02-13 Gabriel Romon

We discuss some open problems in the Geometry of Banach spaces having Ramsey-theoretic flavor. The problems are exposed together with well known results related to them.

Functional Analysis · Mathematics 2011-05-11 Pandelis Dodos , Jordi Lopez-Abad , Stevo Todorcevic

We focus on the new type perturbed metric spaces and introduce a contraction mapping namely new type perturbed Kannan mappings. For these mappings, we show that Banach's fixed point theorem holds. Moreover, this new generalization of…

General Mathematics · Mathematics 2025-05-30 Bekir Danış

We investigate metric projections and distance functions referring to convex bodies in finite-dimensional normed spaces. For this purpose we identify the vector space with its dual space by using, instead of the usual identification via the…

Metric Geometry · Mathematics 2019-08-26 Vitor Balestro , Horst Martini , Ralph Teixeira

In this paper, we investigate a new notion of accretive mappings called generalized $\alpha\beta$-$H((.,.),(.,.))$-mixed accretive mappings in Banach spaces. We extend the concept of proximal-point mappings associated with generalized…

Functional Analysis · Mathematics 2015-10-07 Sanjeev Gupta , Shamshad Husain , Vishnu Narayan Mishra

This paper generalizes results for alternate dual frames in Hilbert spaces on the situation of a Banach space. Additionally some properties of synthesys operator associated with alternate dual frame are investigated. The main result is that…

Functional Analysis · Mathematics 2011-11-01 Sergey Kreys

In this paper, by using admissible sets, we give some fixed point results for orbitally contractions which diminish the radius of invariant convex subsets and orbits. Furthermore, a characterization of the weak normal structure by the fixed…

Functional Analysis · Mathematics 2021-07-01 Abdelkader Dehici , Najeh Redjel , Sami Atailia

We present different extensions of the Banach contraction principle in the $G$-metric space setting. More precisely, we consider mappings for which the contractive condition is satisfied by a power of the mapping and for which the power…

General Topology · Mathematics 2017-04-04 Yaé Olatoundji Gaba

The general problem we address is to develop new methods in the study of projection constants of Banach spaces of multivariate polynomials. The relative projection constant $\boldsymbol{\lambda}(X,Y)$ of a subspace $X$ of a Banach $Y$ is…

Functional Analysis · Mathematics 2022-08-16 Andreas Defant , Daniel Galicer , Martín Mansilla , Mieczysław Mastyło , Santiago Muro

The notion of ball convexity, considered in finite dimensional real Banach spaces, is a natural and useful extension of usual convexity; one replaces intersections of half-spaces by suitable intersections of balls. A subset $S$ of a normed…

Metric Geometry · Mathematics 2017-07-18 Thomas Jahn , Christian Richter , Horst Martini

Let $H$ be a real Hilbert space and $C$ a nonempty closed and convex subset of $H$. Let $P_C: H\rightarrow C$ denote the (standard) metric projection operator. In this paper, we study the G\^ateaux directional differentiability of $P_C$ and…

Functional Analysis · Mathematics 2023-10-26 Jinlu Li , Li Cheng , Lishan Liu , Linsen Xie

Generalized complex geometry, introduced by Hitchin, encompasses complex and symplectic geometry as its extremal special cases. We explore the basic properties of this geometry, including its enhanced symmetry group, elliptic deformation…

Differential Geometry · Mathematics 2007-05-23 Marco Gualtieri

We describe all metric spaces that have sufficently many affine functions. As an application we obtain a metric characterization of linear-convex subsets of Banach spaces.

Metric Geometry · Mathematics 2013-04-25 Petra Schwer , Alexander Lytchak

This paper develops a geometric approach of variational analysis for the case of convex objects considered in locally convex topological spaces and also in Banach space settings. Besides deriving in this way new results of convex calculus,…

Optimization and Control · Mathematics 2017-05-12 Boris Mordukhovich , Nguyen Mau Nam , R. Blake Rector , Tuyen Tran

We show that every metric space with bounded geometry uniformly embeds into an explicit reflexive Banach space (a direct sum of l^p spaces). In the case of discrete groups we show the analogue of a-T-menability. That is, we construct a…

Operator Algebras · Mathematics 2016-09-07 Nathanial Brown , Erik Guentner