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We first prove that for every metrizable space $X$, for every closed subset $F$ whose complement is zero-dimensional, the space $X$ can be embedded into a product space of the closed subset $F$ and a metrizable zero-dimensional space as a…

General Topology · Mathematics 2026-01-13 Yoshito Ishiki

We show that the continuum hypothesis implies there exists a Lindelof space X such that X x X is the union of two metrizable subspaces but X is not metrizable. This gives a consistent solution to a problem of Balogh, Gruenhage, and Tkachuk.…

Logic · Mathematics 2007-05-23 Arnold W. Miller

Given any two Einstein (pseudo-)metrics, with scalar curvatures suitably related, we give an explicit construction of a Poincar\'e-Einstein (pseudo-)metric with conformal infinity the conformal class of the product of the initial metrics.…

Differential Geometry · Mathematics 2009-11-16 A. Rod Gover , Felipe Leitner

We consider notions of metrized categories, and then approximate categorical structures defined by a function of three variables generalizing the notion of $2$-metric space. We prove an embedding theorem giving sufficient conditions for an…

Category Theory · Mathematics 2015-11-06 Abdelkrim Aliouche , Carlos Simpson

We deal with topological spaces homeomorphic to their respective squares. Primarily, we investigate the existence of large families of such spaces in some subclasses of compact metrizable spaces. As our main result we show that there is a…

General Topology · Mathematics 2024-01-17 Jan Dudák , Benjamin Vejnar

Given a structure $\mathcal{M}$ with a definable topology, its open core is a structure defined on the same universe whose language consists of all open sets of all arities definable in $\mathcal{M}$. In response to questions raised by…

Logic · Mathematics 2026-05-14 Alexi Block Gorman , Esther Elbaz Saban

In a recent paper, the authors proved that no spin foliation on a compact enlargeable manifold with Hausdorff homotopy graph admits a metric of positive scalar curvature on its leaves. This result extends groundbreaking results of…

Geometric Topology · Mathematics 2020-02-07 Moulay Tahar Benameur , James L. Heitsch

We prove that it is consistent with ZFC that no sequential topological groups of intermediate sequential orders exist. This shows that the answer to a 1981 question of P.~Nyikos is independent of the standard axioms of set theory. The model…

General Topology · Mathematics 2016-05-02 Alexander Shibakov

We prove a conjecture by A. Pnueli and strengthen it showing a sequence of "counting modalities" none of which is expressible in the temporal logic generated by the previous modalities, over the real line, or over the positive reals.…

Logic in Computer Science · Computer Science 2017-01-11 Yoram Hirshfeld , Alexander Rabinovich

We call a dynamical system on a measurable metric space {\em measure-expansive} if the probability of two orbits remain close each other for all time is negligible (i.e. zero). We extend results of expansive systems on compact metric spaces…

Dynamical Systems · Mathematics 2025-03-24 C. A. Morales

Two structures are said to be equimorphic if each embeds in the other. Such structures cannot be expected to be isomorphic, and in this paper we investigate the special case of linear orders, here also called chains. In particular we…

Combinatorics · Mathematics 2014-07-11 C. Laflamme , M. Pouzet , R. Woodrow

Let f be a continuous map of a complete separable metric space E onto the irrationals. We show that if a complete separable metric space M contains isometric copies of every closed relatively discrete set in E, then M contains also an…

General Topology · Mathematics 2017-06-15 Elżbieta Pol , Roman Pol

Canonical quantization may be approached from several different starting points. The usual approaches involve promotion of c-numbers to q-numbers, or path integral constructs, each of which generally succeeds only in Cartesian coordinates.…

Quantum Physics · Physics 2009-10-31 John R. Klauder

We establish several nonuniqueness results for the problem of finding complete conformal metrics with constant (fourth-order) $Q$-curvature on compact and noncompact manifolds of dimension $\geq5$. Infinitely many branches of metrics with…

Differential Geometry · Mathematics 2021-05-14 Renato G. Bettiol , Paolo Piccione , Yannick Sire

Recently, the author and Bob Coecke have introduced a categorical formulation of Quantum Mechanics. In the present paper, we shall use it to open up a novel perspective on No-Cloning. What we shall find, quite unexpectedly, is a link to…

Quantum Physics · Physics 2012-03-20 Samson Abramsky

Fedorchuk's fully closed (continuous) maps and resolutions are applied in constructions of non-metrizable higher-dimensional analogues of Anderson, Choquet, and Cook's continua. Certain theorems on dimension-lowering maps are proved for…

General Topology · Mathematics 2010-10-19 Jerzy Krzempek

Compact metric spaces form an important class of metric spaces, but the category that they define lacks many important properties such as completeness and cocompleteness. In recent studies of "metric domain theory" and Stone-type dualities,…

Category Theory · Mathematics 2025-01-15 Marco Abbadini , Dirk Hofmann

We consider metrics which are preserved under a $p$-Wasserstein transport map, up to a possible contraction. In the case $p=1$ this corresponds to a metric which is uniformly curved in the sense of coarse Ricci curvature. We investigate the…

Probability · Mathematics 2017-12-08 Florian Völlering

We indicate a way of distinguishing between structures, for which, two structures are said to be separable.Being separable implies being non-isomorphic. We show that for any first order theory $T$ in a countable language, if it has an…

Logic · Mathematics 2012-11-28 Mohammad Assem

We prove that a proper geodesic metric space has non-positive curvature in the sense of Alexandrov if and only if it satisfies the Euclidean isoperimetric inequality for curves. Our result extends to non-geodesic spaces and non-zero…

Differential Geometry · Mathematics 2016-11-17 Alexander Lytchak , Stefan Wenger