6533b7cefe1ef96bd1257a19

RESEARCH PRODUCT

A note on rank 2 diagonals

Santi SpadaroAngelo Bella

subject

DiagonalCardinal invariantsMathematics::General TopologyWeakly Lindelöflcsh:AnalysisSpace (mathematics)01 natural sciencesCombinatoricsBELLACardinalitydual propertiesCardinality boundsFOS: MathematicsRank (graph theory)Continuum (set theory)0101 mathematicsDual propertiesMathematics - General TopologyMathematicsweakly LindelofGδ- diagonallcsh:Mathematics010102 general mathematicsGeneral Topology (math.GN)neighbourhood assignmentGδ-diagonallcsh:QA299.6-433lcsh:QA1-939gδ-diagonal010101 applied mathematicscardinality boundsMathematics::LogicNeighbourhood assignmentSettore MAT/03 - GeometriaGeometry and Topologyweakly lindelöf

description

<p>We solve two questions regarding spaces with a (G<sub>δ</sub>)-diagonal of rank 2. One is a question of Basile, Bella and Ridderbos about weakly Lindelöf spaces with a G<sub>δ</sub>-diagonal of rank 2 and the other is a question of Arhangel’skii and Bella asking whether every space with a diagonal of rank 2 and cellularity continuum has cardinality at most continuum.</p>

10.4995/agt.2020.12065https://dx.doi.org/10.4995/agt.2020.12065