Timeline for product of power sets
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Jul 20, 2017 at 18:44 | comment | added | Andrés E. Caicedo | @Ashutosh Cool! It would be nice to see some details as an answer. | |
| Jul 16, 2017 at 17:28 | comment | added | Ashutosh | Call an infinite cardinal $\kappa$ Kunen if the sigma algebra generated by $\{A \times B : A, B \subseteq \kappa\}$ contains every subset of $\kappa \times \kappa$. The set of Kunen cardinals forms an initial segment of cardinals, closed under countable suprema, with the psuedointersection number (denoted $\mathfrak{p}$) as a member. In the Cohen real model (obtained by adding $\aleph_2$ Cohen reals to $L$) the continuum is not Kunen (see Kunen's 1968 thesis). This also holds in the random real model (obtained by adding $\aleph_2$ random reals to $L$). | |
| Jul 14, 2017 at 1:28 | comment | added | Joel David Hamkins | In particular, the result of Rao mentioned by Michael Greinecker in his answer there mathoverflow.net/a/81491/1946 provides a positive answer for $X$ of $\omega_1$. So this handles $X$ of size continuum under CH. | |
| Jul 13, 2017 at 21:22 | answer | added | Andrés E. Caicedo | timeline score: 6 | |
| Jul 13, 2017 at 20:09 | comment | added | Gerald Edgar | See also mathoverflow.net/q/39882/454 | |
| Jul 13, 2017 at 19:55 | history | edited | Emmanuel Chetcuti |
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| Jul 13, 2017 at 19:35 | review | First posts | |||
| Jul 13, 2017 at 19:52 | |||||
| Jul 13, 2017 at 19:34 | history | asked | Emmanuel Chetcuti | CC BY-SA 3.0 |