Timeline for Some questions about $0^{\sharp}$ and forcing over $L$
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
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| Oct 31, 2013 at 10:36 | history | undeleted | François G. Dorais | ||
| Oct 31, 2013 at 4:19 | history | deleted | Mohammad Golshani | via Vote | |
| S Oct 27, 2013 at 6:07 | history | bounty ended | CommunityBot | ||
| S Oct 27, 2013 at 6:07 | history | notice removed | CommunityBot | ||
| S Oct 19, 2013 at 5:02 | history | bounty started | Mohammad Golshani | ||
| S Oct 19, 2013 at 5:02 | history | notice added | Mohammad Golshani | Canonical answer required | |
| Oct 19, 2013 at 5:02 | history | edited | Mohammad Golshani |
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| Jul 22, 2013 at 3:12 | comment | added | Mohammad Golshani | Assume $V=L$ and suppose there are no inaccessible cardinals. By a result of Jensen, for each regular cardinal $\kappa,$ there exists a $\kappa-$closed $\kappa^+-$Souslin tree $T_{\kappa^+}$ such that forcing with $T_{\kappa^+}\times T_{\kappa^+}$ collapses $\kappa^+$ into $\kappa.$ Let $P$ be the Easton support product of such $T_{\kappa^+}$'s. Then $P$ is as required. Just note that forcing with $P\times P$ collapses all $\kappa^+, \kappa$ regular, and hence by results of Shelah it collapses all uncountable cardinals. | |
| Jul 21, 2013 at 12:51 | comment | added | Noah Schweber | This might be basic, but can you give an example of a tame cardinal-preserving forcing whose square collapses everything to $\omega$? That sounds really cool! | |
| Jul 21, 2013 at 12:18 | history | asked | Mohammad Golshani | CC BY-SA 3.0 |