G(delta) COVERS OF COMPACT SPACES

Autor(es)

Spadaro, S. ^[1] ; Szeptycki, P. ^[2]

Afiliação do(s) autor(es)

^[1] Citta Univ Catania, Univ Catania, Dept Math & Comp Sci, Viale A Doria 6, I-95125 Catania - Italy

^[2] York Univ, Fac Sci & Engn, Dept Math, Toronto, ON M3J 1P3 - Canada

• Tipo de documento: Artigo Científico
• Fonte: ACTA MATHEMATICA HUNGARICA; v. 154, n. 1, p. 252-263, FEB 2018.
• Citações Web of Science: 4

Resumo

We solve a long standing question due to Arhangel'skii by constructing a compact space which has a cover with no continuum-sized ()-dense subcollection. We also prove that in a countably compact weakly Lindelof normal space of countable tightness, every cover has a -sized subcollection with a -dense union and that in a Lindelof space with a base of multiplicity continuum, every cover has a continuum sized subcover. We finally apply our results to obtain a bound on the cardinality of homogeneous spaces which refines De la Vega's celebrated theorem on the cardinality of homogeneous compacta of countable tightness. (AU)

• Processo FAPESP: 13/14640-1 - Conjuntos discretos e invariantes cardinais em topologia conjuntista
• Beneficiário: Santi Domenico Spadaro
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado