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Related papers: Selective screenability in topological groups

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In this paper we show that forcings which are strongly proper for stationarily many countable elementary submodels preserve each of the following properties of topological spaces: countably tight; Lindel\"of; Rothberger; Menger; and a…

Logic · Mathematics 2024-10-04 Thomas Gilton , Jared Holshouser

We prove that the existence of a selective ultrafilter implies the existence of a countably compact Hausdorff group topology on the free Abelian group of size continuum. As a consequence, we show that the existence of a selective…

General Topology · Mathematics 2020-06-25 A. C. Boero , I. Castro-Pereira , A. H. Tomita

We discuss measures, invariant measures on definable groups, and genericity, often in an NIP (failure of the independence property) environment. We complete the proof of the third author's conjectures relating definably compact groups $G$…

Logic · Mathematics 2007-05-23 Ehud Hrushovski , Ya'acov Peterzil , Anand Pillay

We establish that a second countable locally compact groupoid possessing a continuous Haar system is topologically amenable if and only if it is Borel amenable. We give some examples and applications.

Dynamical Systems · Mathematics 2013-04-09 Jean Renault

A joint characterisation of the controllability and observability of a particular kind of discrete system has been developed. The key idea of the procedure can be reduced to a correct choice of the sampling sequence. This freedom, owing to…

Dynamical Systems · Mathematics 2010-06-14 Amparo Fúster-Sabater , J. M. Guillén

We study several properties of expansive group actions on metric spaces and obtain relation between expansivity for subgroup and group actions. Through counter examples necessity of hypothesis are justified. We also study expansivity of…

Dynamical Systems · Mathematics 2018-08-01 Ali Barzanouni , Mahin Sadat Divandar , Ekta Shah

For a class of piecewise deterministic Markov processes, the supports of the invariant measures are characterized. This is based on the analysis of controllability properties of an associated deterministic control system. Its invariant…

Dynamical Systems · Mathematics 2018-04-05 Michel Benaïm , Fritz Colonius , Lettau Ralph

The Turing machine is one of the simple abstract computational devices that can be used to investigate the limits of computability. In this paper, they are considered from several points of view that emphasize the importance and the…

Computational Complexity · Computer Science 2012-03-16 Yaroslav D. Sergeyev , Alfredo Garro

We prove that for certain actions of a discrete countable residually finite amenable group acting on a compact metric space with specification property, periodic measures are dense in the set of invariant measures.

Dynamical Systems · Mathematics 2015-10-20 Xiankun Ren

In this paper we characterize [strict] o-boundedness of the free (abelian) topological group F(X) (A(X)) as well as the free locally-convex linear topological space L(X) in terms of properties of a Tychonoff space X. These properties appear…

General Topology · Mathematics 2007-05-23 Lyubomyr Zdomskyy

We prove that every countable subgroup of a compact metrizable abelian group has a characterizing set. As an application, we answer several questions on maximally almost periodic (MAP) groups and give a characterization of the class of…

General Topology · Mathematics 2007-05-23 Dikran Dikranjan , Kenneth Kunen

We introduce a topological property for finitely generated groups called stackable that implies the existence of an inductive procedure for constructing van Kampen diagrams with respect to a particular finite presentation. We also define…

Group Theory · Mathematics 2014-10-10 Mark Brittenham , Susan Hermiller

Whenever P is a proper definable forcing for adding a real, the countable support iteration of P has all the preservation properties it can possibly have, within a wide syntactically identified class of properties.

Logic · Mathematics 2007-05-23 Jindrich Zapletal

In this paper, we discuss some properties of of $G$-hull, $G$-kernel and $G$-connectedness, and extend some results of \cite{life34}. In particular, we prove that the $G$-connectedness are preserved by countable product. Moreover, we…

General Topology · Mathematics 2019-12-02 Yongxing Wu , Fucai Lin

We study selective and game-theoretic versions of properties like the ccc, weak Lindel\"ofness and separability, giving various characterizations of them and exploring connections between these properties and some classical cardinal…

General Topology · Mathematics 2015-05-14 Leandro Aurichi , Santi Spadaro , Lyubomyr Zdomskyy

We study monitorable sets from a topological standpoint. In particular, we use descriptive set theory to describe the complexity of the family of monitorable sets in a countable space $X$. When $X$ is second countable, we observe that the…

Logic · Mathematics 2026-01-09 Riccardo Camerlo , Francesco Dagnino

Definable topological groups whose topologies are affine have definable $\mathcal C^r$ structures in d-minimal expansions of ordered fields, where $r$ is a positive integer. We prove this fact using a new notion called partition degree of a…

Logic · Mathematics 2024-07-24 Masato Fujita

Selective versions of screenability and of strong screenability coincide in a large class of spaces. We show that the corresponding games are not equivalent in even such standard metric spaces as the closed unit interval. We identify…

General Topology · Mathematics 2015-03-31 Liljana Babinkostova , Marion Scheepers

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

We establish a criterion for determining when a family of geometric functors is jointly conservative through the lens of purity in compactly generated triangulated categories. We introduce the notion of pure descendability and we apply it…

Algebraic Topology · Mathematics 2026-02-17 Natàlia Castellana , Juan Omar Gómez