| Title:
|
No hedgehog in the product? (English) |
| Author:
|
Simon, Petr |
| Author:
|
Tironi, Gino |
| Language:
|
English |
| Journal:
|
Commentationes Mathematicae Universitatis Carolinae |
| ISSN:
|
0010-2628 (print) |
| ISSN:
|
1213-7243 (online) |
| Volume:
|
43 |
| Issue:
|
2 |
| Year:
|
2002 |
| Pages:
|
349-361 |
| . |
| Category:
|
math |
| . |
| Summary:
|
Assuming OCA, we shall prove that for some pairs of Fréchet $\alpha_4$-spaces $X, Y$, the Fréchetness of the product $X\times Y$ implies that $X\times Y$ is $\alpha_4$. Assuming MA, we shall construct a pair of spaces satisfying the assumptions of the theorem. (English) |
| Keyword:
|
Fréchet space |
| Keyword:
|
$\alpha _4$-space |
| Keyword:
|
Fréchet fan |
| Keyword:
|
$(\kappa, \kappa )$-good set |
| MSC:
|
03E50 |
| MSC:
|
03E65 |
| MSC:
|
54B10 |
| MSC:
|
54D55 |
| MSC:
|
54G20 |
| idZBL:
|
Zbl 1090.54024 |
| idMR:
|
MR1922133 |
| . |
| Date available:
|
2009-01-08T19:22:38Z |
| Last updated:
|
2012-04-30 |
| Stable URL:
|
http://hdl.handle.net/10338.dmlcz/119325 |
| . |
| Reference:
|
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| Reference:
|
[BL] Brendle J., LaBerge T.: Forcing tightness of products of fans.Fund. Math. 150 3 (1996), 211-226. |
| Reference:
|
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| Reference:
|
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| Reference:
|
[MS] Martin D.A., Solovay R.M.: Internal Cohen extension.Ann. Math. Logic 2 (1970), 143-178. |
| Reference:
|
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| Reference:
|
[No] : Products of $\langle \alpha_i\rangle$-spaces. |
| Reference:
|
[Ny] Nyikos P.J.: Convergence in topology.in: Recent Progress in General Topology, ed. by M. Hušek and J. van Mill, North-Holland, 1992 pp.537-570. |
| Reference:
|
[Si] Simon P.: A hedgehog in the product.Acta. Univ. Carolin. Math. Phys. 39 (1998), 147-153. |
| Reference:
|
[Sw] Siwiec F.: Sequence covering and countably bi-quotient mappings.Gen. Topology Appl. 1 (1971), 143-154. |
| Reference:
|
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| . |
