Countable compactness of lexicographic products of GO-spaces

Nobuyuki Kemoto

Commentationes Mathematicae Universitatis Carolinae (2019)

  • Volume: 60, Issue: 3, page 421-439
  • ISSN: 0010-2628

Abstract

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We characterize the countable compactness of lexicographic products of GO-spaces. Applying this characterization about lexicographic products, we see:

the lexicographic product X 2 X^2 of a countably compact GO-space X X need not be countably compact,

ω 1 2 \omega _1^2 , ω 1 × ω \omega _1\times \omega , ( ω + 1 ) × ( ω 1 + 1 ) × ω 1 × ω (\omega +1)\times (\omega _1+1)\times \omega _1\times \omega , ω 1 × ω × ω 1 \omega _1\times \omega \times \omega _1 , ω 1 × ω × ω 1 × ω × \omega _1\times \omega \times \omega _1\times \omega \times \cdots , ω 1 × ω ω \omega _1\times \omega ^\omega , ω 1 × ω ω × ( ω + 1 ) \omega _1\times \omega ^\omega \times (\omega +1) , ω 1 ω \omega _1^\omega , ω 1 ω × ( ω 1 + 1 ) \omega _1^\omega \times (\omega _1+1) and n ω ω n + 1 \prod _{n\in \omega }\omega _{n+1} are countably compact,

ω × ω 1 \omega \times \omega _1 , ( ω + 1 ) × ( ω 1 + 1 ) × ω × ω 1 (\omega +1)\times (\omega _1+1)\times \omega \times \omega _1 , ω × ω 1 × ω × ω 1 × \omega \times \omega _1\times \omega \times \omega _1\times \cdots , ω × ω 1 ω \omega \times \omega _1^\omega , ω 1 × ω ω × ω 1 \omega _1\times \omega ^\omega \times \omega _1 , ω 1 ω × ω \omega _1^\omega \times \omega , n ω ω n \prod _{n\in \omega }\omega _{n} and n ω ω n + 1 \prod _{n\le \omega }\omega _{n+1} are not countably compact,

[ 0 , 1 ) × ω 1 [0,1)_\mathbb {R}\times \omega _1 , where [ 0 , 1 ) [0,1)_\mathbb {R} denotes the half open interval in the real line \mathbb {R} , is not countably compact,

ω 1 × [ 0 , 1 ) \omega _1\times [0,1)_\mathbb {R} is countably compact,

both 𝕊 × ω 1 \mathbb {S}\times \omega _1 and ω 1 × 𝕊 \omega _1\times \mathbb {S} are not countably compact,

ω 1 × ( - ω 1 ) \omega _1\times (-\omega _1) is not countably compact, where for a GO-space X = X , < X , τ X X=\langle X,<_X,\tau _X\rangle , - X -X denotes the GO-space X , > X , τ X \langle X,>_X,\tau _X\rangle .

How to cite

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Kemoto, Nobuyuki. "Countable compactness of lexicographic products of GO-spaces." Commentationes Mathematicae Universitatis Carolinae 60.3 (2019): 421-439. <http://eudml.org/doc/294820>.

@article{Kemoto2019,
abstract = {We characterize the countable compactness of lexicographic products of GO-spaces. Applying this characterization about lexicographic products, we see: },
author = {Kemoto, Nobuyuki},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {lexicographic product; GO-space; LOTS; countably compact product},
language = {eng},
number = {3},
pages = {421-439},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {Countable compactness of lexicographic products of GO-spaces},
url = {http://eudml.org/doc/294820},
volume = {60},
year = {2019},
}

TY - JOUR
AU - Kemoto, Nobuyuki
TI - Countable compactness of lexicographic products of GO-spaces
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 2019
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 60
IS - 3
SP - 421
EP - 439
AB - We characterize the countable compactness of lexicographic products of GO-spaces. Applying this characterization about lexicographic products, we see:
LA - eng
KW - lexicographic product; GO-space; LOTS; countably compact product
UR - http://eudml.org/doc/294820
ER -

References

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  1. Engelking R., General Topology, Sigma Series in Pure Mathematics, 6, Herdermann Verlag, Berlin, 1989. Zbl0684.54001MR1039321
  2. Faber M. J., Metrizability in Generalized Ordered Spaces, Mathematical Centre Tracts, 53, Mathematisch Centrum, Amsterdam, 1974. Zbl0282.54017MR0418053
  3. Kemoto N., Normality of products of GO-spaces and cardinals, Topology Proc. 18 (1993), 133–142. MR1305127
  4. Kemoto N., 10.1016/j.topol.2013.11.005, Topology Appl. 162 (2014), 20–33. MR3144657DOI10.1016/j.topol.2013.11.005
  5. Kemoto N., 10.1016/j.topol.2017.09.026, Topology Appl. 231 (2017), 276–291. MR3712968DOI10.1016/j.topol.2017.09.026
  6. Kemoto N., 10.1016/j.topol.2017.10.017, Topology Appl. 232 (2017), 267–280. MR3720898DOI10.1016/j.topol.2017.10.017
  7. Kemoto N., 10.1016/j.topol.2018.03.004, Topology Appl. 240 (2018), 35–58. MR3784395DOI10.1016/j.topol.2018.03.004
  8. Kemoto N., The structure of the linearly ordered compactifications of GO-spaces, Topology Proc. 52 (2018), 189–204. MR3734101
  9. Kunen K., Set Theory. An Introduction to Independence Proofs, Studies in Logic and the Foundations of Mathematics, 102, North-Holland Publishing, Amsterdam, 1980. Zbl0534.03026MR0597342
  10. Lutzer D. J., On generalized ordered spaces, Dissertationes Math. Rozprawy Mat. 89 (1971), 32 pages. MR0324668
  11. Miwa T., Kemoto N., 10.1016/0166-8641(93)90057-K, Topology Appl. 54 (1993), no. 1–3, 133–140. MR1255783DOI10.1016/0166-8641(93)90057-K

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