Search results for "Selection principles"

showing 3 items of 3 documents

Infinite games and chain conditions

2015

We apply the theory of infinite two-person games to two well-known problems in topology: Suslin's Problem and Arhangel'skii's problem on $G_\delta$ covers of compact spaces. More specifically, we prove results of which the following two are special cases: 1) every linearly ordered topological space satisfying the game-theoretic version of the countable chain condition is separable and 2) in every compact space satisfying the game-theoretic version of the weak Lindel\"of property, every cover by $G_\delta$ sets has a continuum-sized subcollection whose union is $G_\delta$-dense.

Discrete mathematicsAlgebra and Number TheoryProperty (philosophy)010102 general mathematicsGeneral Topology (math.GN)Mathematics::General Topology010103 numerical & computational mathematicsTopological space01 natural sciencesSeparable spaceCompact spaceChain (algebraic topology)Cover (topology)Countable chain conditionFOS: Mathematicstopological gamesselection principles0101 mathematicscardinal inequalitiesChain conditionsTopology (chemistry)MathematicsMathematics - General Topology
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Comparing weak versions of separability

2012

Our aim is to investigate spaces with sigma-discrete and meager dense sets, as well as selective versions of these properties. We construct numerous examples to point out the differences between these classes while answering questions of Tkachuk [30], Hutchinson [17] and the authors of [8].

Discrete mathematicsSelection principlesGeneral Topology (math.GN)Mathematics::General TopologyCorson compactSeparableSeparable spaceDiscreteFOS: MathematicsPoint (geometry)Geometry and Topology54D65 54B10 54C35Construct (philosophy)MathematicsMathematics - General Topology
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Selective versions of chain condition-type properties

2015

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 invariants of the continuum.

Pure mathematicsRothberger spaceGeneral MathematicsMathematics::General TopologyType (model theory)01 natural sciencesChain (algebraic topology)FOS: Mathematicstopological games0101 mathematicsMathematics - General TopologyMathematicsDiscrete mathematicsContinuum (topology)010102 general mathematicsGeneral Topology (math.GN)TEORIA DOS JOGOSMathematics - Logic16. Peace & justice010101 applied mathematicsMathematics::LogicPrimary: 54A25 03E17 91A44 Secondary: 54D35 54D10selection principlescardinal inequalitiesLogic (math.LO)Chain conditionsActa Mathematica Hungarica
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