A note on the tightness of Gδ-modifications

Toshimichi Usuba

doi:10.1016/j.topol.2019.106820

A note on the tightness of G_δ-modifications

Toshimichi Usuba

School of Fundamental Science and Engineering

Research output: Contribution to journal › Article

Abstract

We construct a normal countably tight T₁ space X with t(X_δ)>2^ω. This is an answer to the question posed by Dow-Juhász-Soukup-Szentmiklóssy-Weiss [5]. We also show that if the continuum is not so large, then the tightness of G_δ-modifications of countably tight spaces can be arbitrary large up to the least ω₁-strongly compact cardinal.

Original language	English
Article number	106820
Journal	Topology and its Applications
Volume	265
DOIs	https://doi.org/10.1016/j.topol.2019.106820
Publication status	Published - 2019 Sep 15

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Keywords

Countably tight
G-modification
Saturated filter
ω-strongly compact cardinal

ASJC Scopus subject areas

Geometry and Topology

Cite this

Usuba, T. (2019). A note on the tightness of G_δ-modifications. Topology and its Applications, 265, [106820]. https://doi.org/10.1016/j.topol.2019.106820

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10.1016/j.topol.2019.106820