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Related papers: On U-equivalence spaces

200 papers

The notion of a coherent space is a nonlinear version of the notion of a complex Euclidean space: The vector space axioms are dropped while the notion of inner product is kept. Coherent spaces provide a setting for the study of geometry in…

Mathematical Physics · Physics 2018-10-01 Arnold Neumaier

Let A and B be normal matrices with coefficients that are continuous complex-valued functions on a topological space X that has the homotopy type of a CW complex, and suppose these matrices have the same distinct eigenvalues at each point…

Operator Algebras · Mathematics 2018-12-31 Greg Friedman , Efton Park

These notes are an introduction to the theory of quantum symmetries of finite and infinite sets, graphs, and locally compact spaces.

Quantum Algebra · Mathematics 2026-03-27 Christian Voigt

In this paper, we study some topological characteristics of the n-normed spaces. We observe convergence sequences, closed sets, and bounded sets in the n-normed spaces using norms of quotient spaces that will be constructed. These norms…

Functional Analysis · Mathematics 2018-10-19 Harmanus Batkunde , Hendra Gunawan

For a given poset, we consider its representations by systems of subspaces of a unitary space ordered by inclusion. We classify such systems for all posets for which an explicit classification is possible.

We present a notion of precompactness, and study some of its properties, in the context of apartness spaces whose apartness structure is not necessarily induced by any uniform one. The presentation lies entirely with a Bishop-style…

Logic in Computer Science · Computer Science 2015-07-01 Douglas S Bridges

The concept of typed topological space is introduced, for which open sets in a topology on a finite set will be assigned types (from lattice). The neighborhood system of a point, the closure and the connectedness can be defined according to…

General Topology · Mathematics 2018-04-13 Wanjun Hu

The aim of this paper is to investigate the equivalence conditions for uniform perfectness of quasi-metric spaces. We also obtain the invariant property of uniform perfectness under quasim\"obius maps in quasi-metric spaces. In the end, two…

Complex Variables · Mathematics 2019-03-05 Qingshan Zhou , Yaxiang Li , Ailing Xiao

An open (resp., closed) subset A of a topological space (X, T ) is called C-open (resp., C-closed) set if cl(A) \ A (resp., A \ int(A)) is a countable set. This paper aims to present the concept of C-open and C-closed sets. We first…

General Topology · Mathematics 2023-05-08 M. H. Alqahtani

The analog of the Schauder inequality for closed surfaces in Euclidean spaces is obtained in this article.

Differential Geometry · Mathematics 2007-06-18 Andrei Bodrenko

In this paper, we introduce round and sleek topological spaces and study their properties.

General Topology · Mathematics 2022-10-28 Jitender Singh

We completely characterize the validity of the inequality $\|u\|_{Y(\mathbb{R}^n)}\leq C \|\nabla^m u\|_{X(\mathbb{R}^n)}$, where $X$ and $Y$ are rearrangement-invariant spaces, by reducing it to a considerably simpler one-dimensional…

Functional Analysis · Mathematics 2021-01-21 Zdeněk Mihula

This paper collects results and open problems concerning several classes of functions that generalize uniform continuity in various ways, including those metric spaces (generalizing Atsuji spaces) where all continuous functions have the…

General Topology · Mathematics 2011-12-07 Dikran Dikranjan , Dušan Repovš

We consider a version of the open-open game, indicating its connections with universally Kuratowski-Ulam spaces. We show that: Every I-favorable space is universally Kuratowski-Ulam, (Theorem 8); If a compact space Y is I-favorable, then…

General Topology · Mathematics 2016-12-30 A. Kucharski , SZ. Plewik

In this note we observe that the notion of an induced representation has an analog for quasi-actions. We then use induced quasi-actions to refine some earlier rigidity results for product spaces.

Group Theory · Mathematics 2008-01-22 Bruce Kleiner , Bernhard Leeb

We demonstrate the equivalence of two classes of $D$-invariant polynomial subspaces introduced in [8] and [9], i.e., these two classes of subspaces are different representations of the breadth-one $D$-invariant subspace. Moreover, we solve…

Numerical Analysis · Mathematics 2014-07-29 Xue Jiang , Shugong Zhang

Function space topologies are developed for EC(Y,Z), the class of equi-continuous mappings from a topological space Y to a uniform space Z. Properties such as splittingness, admissibility etc. are defined for such spaces. The net theoretic…

General Mathematics · Mathematics 2020-01-03 Ankit Gupta , Ratna Dev Sarma

A Cech closure space $(X,u)$ is a set $X$ with a (Cech) closure operator $u$ which need not be idempotent. Many properties which hold in topological spaces hold in Cech closure spaces as well. The notions of proper (splitting) and…

General Topology · Mathematics 2007-05-23 Mila Mrsevic

Starting categorically, we give simple and precise models of equivariant classifying spaces. We need these models for work in progress in equivariant infinite loop space theory and equivariant algebraic K-theory, but the models are of…

Algebraic Topology · Mathematics 2018-03-16 B. J. Guillou , J. P. May , M. Merling

This paper investigates spaces equipped with a family of metric-like functions satisfying certain axioms. These functions provide a unified framework for defining topology, uniformity, and diffeology. The framework is based on a family of…

General Topology · Mathematics 2026-03-25 Masaki Taho