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Related papers: Definable Functions in Urysohn's Metric Space

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There are two definitions of the measurable functional on the topological vector space: as a linear and measurable real-valued function and as a pointwise limit of the sequence of the continious linear functionals. In general case they are…

Functional Analysis · Mathematics 2016-02-23 Denis Fufaev

We derive upper bounds on the difference between the orthogonal projections of a smooth function $u$ onto two finite element spaces that are nearby, in the sense that the support of every shape function belonging to one but not both of the…

Numerical Analysis · Mathematics 2014-08-19 Evan S. Gawlik , Adrian J. Lew

In this paper, using the existence of infinite equidistant subsets of closed balls, we characterize the injectivity of ultrametric spaces for finite ultrametric spaces, which also gives a characterization of the Urysohn universal…

Metric Geometry · Mathematics 2024-09-19 Yoshito Ishiki

We study definably complete locally o-minimal expansions of ordered groups in this paper. A definable continuous function defined on a closed, bounded and definable set behave like a continuous function on a compact set. We demonstrate…

Logic · Mathematics 2023-06-09 Masato Fujita

Uniform measures are defined as the functionals on the space of bounded uniformly continuous functions that are continuous on bounded uniformly equicontinuous sets. If every cardinal has measure zero then every countably additive measure is…

Functional Analysis · Mathematics 2007-05-23 Jan Pachl

Let $(M,g)$ be a compact Riemannian manifold on dimension $n \geq 4$ not conformally diffeomorphic to the sphere $S^n$. We prove that a smooth function $f$ on $M$ is a critical function for a metric $\tilde{g}$ conformal to $g$ if and only…

Differential Geometry · Mathematics 2007-05-23 Emmanuel Humbert , Michel Vaugon

We prove that every vertically nearly separately continuous function defined on a product of a strong PP-space and a topological space and with values in a strongly $\sigma$-metrizable space with a special stratification, is a pointwise…

General Topology · Mathematics 2014-07-23 Olena Karlova

computable functions are defined by abstract finite deterministic algorithms on many-sorted algebras. We show that there exist finite universal algebraic specifications that specify uniquely (up to isomorphism) (i) all abstract computable…

Logic in Computer Science · Computer Science 2007-05-23 J. V. Tucker , J. I. Zucker

According to Kiyoshi Igusa a generalized Morse function on an n-dimensional manifold M is a smooth function with only Morse and birth-death singularities and a framed function is a generalized Morse function with an additional structure: a…

Geometric Topology · Mathematics 2011-08-05 Yakov M. Eliashberg , Nikolai M. Mishachev

We prove that in a Euclidean space of dimension at least two, there exists a compact set of Lebesgue measure zero such that any real-valued Lipschitz function defined on the space is differentiable at some point in the set. Such a set is…

Functional Analysis · Mathematics 2011-05-17 Michael Doré , Olga Maleva

We give necessary and sufficient conditions on a non-oscillatory curve in an o-minimal field such that, for any bounded definable function, the germ of the function on an initial segment of the curve can be continuously extended to a closed…

Logic · Mathematics 2011-04-22 Janak Ramakrishnan

In the absence of the Axiom of Choice, necessary and sufficient conditions for a locally compact Hausdorff space to have all non-empty second-countable compact Hausdorff spaces as remainders are given in $\mathbf{ZF}$. Among other…

General Topology · Mathematics 2020-09-22 Kyriakos Keremedis , Eleftherios Tachtsis , Eliza Wajch

We prove a theorem which provides a method for constructing points on varieties defined by certain smooth functions. We require that the functions are definable in a definably complete expansion of a real closed field and are locally…

Logic · Mathematics 2014-02-26 G. O. Jones , A. J. Wilkie

The main purpose is to establish two theorems about closed 0-definable subsets $A$ of an affine space $K^{n}$ over a Hensel minimal field $K$. The first, being a non-Archimedean counterpart of one from o-minimal geometry, states that every…

Logic · Mathematics 2026-04-14 Krzysztof Jan Nowak

We generalize some classical results about quasicontinuous and separately continuous functions with values in metrizable spaces to functions with values in certain generalized metric spaces, called Maslyuchenko spaces. We establish…

General Topology · Mathematics 2021-11-01 Taras Banakh

In this paper we analyse the structure of the spaces of smooth type functions, generated by elements of arbitrary Hilbert spaces, as a continuation of the research in our previous papers in this series. We prove that these spaces are…

Functional Analysis · Mathematics 2018-12-05 Aparajita Dasgupta , Michael Ruzhansky

Let $R$ be an o-minimal expansion of the real field. We show that the Hausdorff dimension of an $R$-definable metric space is an $R$-definable function of the parameters defining the metric space. We also show that the Hausdorff dimension…

Logic · Mathematics 2015-10-27 Jana Maříková , Erik Walsberg

WWe define the notion of a random metric space and prove that with probability one such a space is isometricto the Urysohn universal metric space. The main technique is the study of universal and random distance matrices; we relate the…

Representation Theory · Mathematics 2015-06-26 A. M. Vershik

Recall that the Rado graph is the unique countable graph that realizes all one-point extensions of its finite subgraphs. The Rado graph is well-known to be universal and homogeneous in the sense that every isomorphism between finite…

Logic · Mathematics 2018-07-17 Jan Grebík

S-metric and b-metric spaces are metrizable, but it is still quite impossible to get an explicit form of the concerned metric function. To overcome this, the notion of $\phi$-metric is developed by making a suitable modification in triangle…

General Mathematics · Mathematics 2023-08-21 Abhishikta Das , Anirban Kundu , T. Bag