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Related papers: Selective separability and $q^+$ on maximal spaces

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We give a counterexample to a conjecture of S.E. Morris by showing that there is a compact plane set X such that R(X) has no non-zero, bounded point derivations but such that R(X) is not weakly amenable. We also give an example of a…

Functional Analysis · Mathematics 2007-05-23 J. F. Feinstein

Let X' be the toroidal compactification of the quotient of the complex 2-ball by a torsion free lattice G of SU(2,1). We say that X'is co-abelian if there is an abelian surface, birational to X'. The present work can be viewed as an…

Algebraic Geometry · Mathematics 2015-03-13 Azniv Kirkor Kasparian

We define a class of insulators with gapless surface states protected from localization due to the statistical properties of a disordered ensemble, namely due to the ensemble's invariance under a certain symmetry. We show that these…

Mesoscale and Nanoscale Physics · Physics 2014-04-23 I. C. Fulga , B. van Heck , J. M. Edge , A. R. Akhmerov

A topology $\tau$ on a set $X$ is called maximal connected if it is connected, but no strictly finer topology $\tau^* > \tau$ is connected. We consider a construction of so-called tree sums of topological spaces, and we show how this…

General Topology · Mathematics 2018-12-04 Adam Bartoš

All spaces are assumed to be separable and metrizable. Our main result is that the statement "For every space $X$, every closed subset of $X$ has the perfect set property if and only if every analytic subset of $X$ has the perfect set…

Logic · Mathematics 2014-08-25 Andrea Medini

Choosing an encoding over binary strings for input/output to/by a Turing Machine is usually straightforward and/or inessential for discrete data (like graphs), but delicate -- heavily affecting computability and even more computational…

Logic in Computer Science · Computer Science 2018-12-11 Akitoshi Kawamura , Donghyun Lim , Svetlana Selivanova , Martin Ziegler

We provide a detailed study of two properties of spaces and pairs of spaces, the surjection property and the epsilon-surjection property, that were recently introduced to characterize the notion of computable type arising from computability…

General Topology · Mathematics 2024-07-10 Djamel Eddine Amir , Mathieu Hoyrup

We introduce a topology on the space of all isomorphism types represented in a given class of countable models, and use this topology as an aid in classifying the isomorphism types. This mixes ideas from effective descriptive set theory and…

Logic · Mathematics 2019-08-20 Russell Miller

A topological space is domain-representable (or, has a domain model) if it is homeomorphic to the maximal point space $\mbox{Max}(P)$ of a domain $P$ (with the relative Scott topology). We first construct an example to show that the set of…

General Topology · Mathematics 2025-02-27 Xiaoyong Xi , Chong Shen , Dongsheng Zhao

In a separably connected space any two points are contained in a separable connected subset. We show a mechanism that takes a connected bounded metric space and produces a complete connected metric space whose separablewise components form…

General Topology · Mathematics 2009-03-30 T. Banakh , M. Vovk , M. R. Wójcik

In spaces of metrics, we investigate topological distributions of the doubling property, the uniform disconnectedness, and the uniform perfectness, which are the quasi-symmetrically invariant properties appearing in the David--Semmes…

Metric Geometry · Mathematics 2021-05-12 Yoshito Ishiki

Below, by space we mean a separable metrizable zero-dimensional space. It is studied when the space can be embedded in a Cantor set while maintaining the algebraic structure. Main results of the work: every space is an open retract of a…

General Topology · Mathematics 2023-06-13 Evgenii Reznichenko

In this paper we continue to study the property of separability of functional space C(X) with the open-point and bi-point-open topologies.

General Topology · Mathematics 2016-04-18 Alexander V. Osipov

In this paper, we study the optimal transport problem induced by separable cost functions. In this framework, transportation can be expressed as the composition of two lower-dimensional movements. Through this reformulation, we prove that…

Optimization and Control · Mathematics 2021-05-18 Gennaro Auricchio

A compact space X is I-favorable if, and only if X can be representing as a limit of $\sigma$-complete inverse system of compact metrizable spaces with skeletal bonding maps.

General Topology · Mathematics 2008-03-03 Andrzej Kucharski , Szymon Plewik

We obtain an improvement of some coloring theorems from \cite{nsbpr}, \cite{819}, and \cite{APAL} for the case where the singular cardinal in question has countable cofinality. As a corollary, we obtain an "idealized" version of the…

Logic · Mathematics 2012-10-23 Todd Eisworth

The Kantorovich-Rubinshtein metric is an $L^1$-like metric on spaces of probability distributions that enjoys several serendipitous properties. It is complete separable if the underlying metric space of points is complete separable, and in…

General Topology · Mathematics 2022-12-23 Jean Goubault-Larrecq

In a recent paper, two multi-representations for the measurable sets in a computable measure space have been introduced, which prove to be topologically complete w.r.t. certain topological properties. In this contribution, we show them…

Computational Complexity · Computer Science 2010-06-03 Yongcheng Wu

A density operator of a bipartite quantum system is called robustly separable if it has a neighborhood of separable operators. Given a bipartite density matrix, its property to be robustly separable is reduced, using the continuous ensemble…

Quantum Physics · Physics 2007-05-23 Roman R. Zapatrin

We study computable topological spaces and semicomputable and computable sets in these spaces. In particular, we investigate conditions under which semicomputable sets are computable. We prove that a semicomputable compact manifold $M$ is…

Logic · Mathematics 2017-01-18 Zvonko Iljazović , Igor Sušić