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Related papers: Near-selection theorems for C-spaces

200 papers

The Nash-Kuiper Theorem states that the collection of $C^1$-isometric embeddings from a Riemannian manifold $M^n$ into $\mathbb{E}^N$ is $C^0$-dense within the collection of all smooth 1-Lipschitz embeddings provided that $n < N$. This…

Differential Geometry · Mathematics 2016-09-08 Barry Minemyer

Given a compact metric space (X,d) equipped with a non-atomic, probability measure m and a real, positive decreasing function p we consider a `natural' class of limsup subsets La(p) of X. The classical limsup sets of `well approximable'…

Number Theory · Mathematics 2007-05-23 Victor Beresnevich , Detta Dickinson , Sanju Velani

A characterization of $n$-dimensional spaces via continuous selections avoiding $Z_n$-sets is given, and a selection theorem for strongly countable-dimensional spaces is established. We apply these results to prove a generalized Ostrand's…

General Topology · Mathematics 2007-05-23 V. Gutev , V. Valov

We introduce two new algebraic invariants, the (co)homological distances between continuous maps, which provide computable lower bounds for the homotopic distance and strictly refine the classical cup-length estimates. We then define the…

Algebraic Topology · Mathematics 2025-11-26 Enrique Macías-Virgós , Ángel Méndez-Vázquez , David Mosquera-Lois

Let $Y\subset{\mathbb R}^n$ be a triangulable set and let $r$ be either a positive integer or $r=\infty$. We say that $Y$ is a $\mathscr{C}^r$-approximation target space, or a $\mathscr{C}^r\text{-}\mathtt{ats}$ for short, if it has the…

Differential Geometry · Mathematics 2021-03-23 José F. Fernando , Riccardo Ghiloni

In this note, we characterize when the Vietoris space of compact subsets of a given space has the Hurewicz property in terms of a selection principle on the given space itself using $k$-covers and the notion of groupability introduced by…

General Topology · Mathematics 2023-08-22 Christopher Caruvana

We consider the Complex Stone-Weierstrass Property (CSWP), which is the complex version of the Stone-Weierstrass Theorem. If X is a compact subspace of a product of three linearly ordered spaces, then X has the CSWP if and only if X has no…

General Topology · Mathematics 2007-05-23 Kenneth Kunen

With a new proof approach we prove in a more general setting the classical convergence theorem that almost everywhere convergence of measurable functions on a finite measure space implies convergence in measure. Specifically, we generalize…

General Mathematics · Mathematics 2020-05-15 Yu-Lin Chou

It is introduced the concept of a quasi-king space, which is a natural generalisation of a king space. In the realm of suborderable spaces, king spaces are precisely the compact spaces, so are the quasi-king spaces. In contrast, quasi-king…

General Topology · Mathematics 2019-02-05 Valentin Gutev

We prove that all the compact metric spaces are in the closure of the class of full matrix algebras for the quantum Gromov-Hausdorff propinquity. We also show that given an action of a compact metrizable group G on a quasi-Leibniz compact…

Operator Algebras · Mathematics 2021-11-15 Konrad Aguilar , Frederic Latremoliere

This paper concerns the self-similarity of topological spaces, in the sense defined in math.DS/0411344. I show how to recognize self-similar spaces, or more precisely, universal solutions of self-similarity systems. Examples include the…

Dynamical Systems · Mathematics 2007-05-23 Tom Leinster

In this paper, we give a topological version of Scott convergence theorem for locally hypercompact spaces. We introduce the notion of $\mathcal{S}^*_X$-convergence on a $T_0$ topological space $X$, and define the notion of finitely…

General Topology · Mathematics 2023-08-09 Yuxu Chen , Hui Kou

Matrices are typically considered over fields or rings. Motivated by applications in parametric differential equations and data-driven modeling, we suggest to study matrices with entries from a Hilbert space and present an elementary theory…

Numerical Analysis · Mathematics 2025-05-09 Stanislav Budzinskiy

We use non-symmetric distances to give a self-contained account of C*-algebra filters and their corresponding compact projections, simultaneously simplifying and extending their general theory.

Operator Algebras · Mathematics 2019-11-19 Tristan Bice , Alessandro Vignati

The Hausdorff-Alexandroff Theorem states that any compact metric space is the continuous image of Cantor's ternary set $C$. It is well known that there are compact Hausdorff spaces of cardinality equal to that of $C$ that are not continuous…

Dynamical Systems · Mathematics 2017-10-24 Fabian Dreher , Tony Samuel

We prove the Derived Mapping Space Lemma, which generalizes the central theorem of Cisinski's work on calculus of fractions for $\infty$-categories, and allows us to provide a unified framework for analyzing mapping spaces in localizations…

Algebraic Topology · Mathematics 2025-09-15 Kensuke Arakawa , Daniel Carranza , Chris Kapulkin

We introduce a notion of vague convergence for random marked metric measure spaces. Our main result shows that convergence of the moments of order $k \ge 1$ of a random marked metric measure space is sufficient to obtain its vague…

Probability · Mathematics 2024-12-23 Félix Foutel-Rodier

The Choquet - Bishop - de Leeuw theorem states that each element of a compact convex subset of a locally convex topological Hausdorff space is a barycenter of a probability measure supported by the set of extreme points of that set. By the…

Functional Analysis · Mathematics 2007-05-23 Piotr Puchała

We display four approximation theorems for manifold-valued mappings. The first one approximates holomorphic embeddings on pseudoconvex domains in $\Bbb C^n$ with holomorphic embeddings with dense images. The second theorem approximates…

Complex Variables · Mathematics 2023-06-21 Giovanni Domenico Di Salvo

We introduce a hypertopology, induced by an inframetric up to full quantum isometry, on the class of pointed proper quantum metric spaces, which are separable, possibly non-unital, C*-algebras endowed with an analogue of the Lipschitz…

Operator Algebras · Mathematics 2025-12-04 Frederic Latremoliere