Timeline for Definability of ground model
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 12, 2011 at 13:45 | comment | added | Joel David Hamkins | Well, the fact certainly would have fit into the theme of our paper, and this is a topic in which I am keenly interested. Thanks for the support! | |
| Dec 12, 2011 at 6:30 | comment | added | Asaf Karagila♦ | Joel: Ugh. For crying out loud... if you guys didn't show it, then how come I know that fact? My mind likes to play these cruel tricks on me. This is not the first time that I have mistakenly attributed a result to someone or pointed to a specific paper. In this case, I suppose it's both. It's still a mystery of how would I know that otherwise... (And also, you did come and gave a great answer - but that wasn't the surprising part as you wouldn't be at 50k reputation otherwise) | |
| Dec 12, 2011 at 3:41 | comment | added | Joel David Hamkins | Asaf, thanks very much for the vote of confidence! But do Jonas, Gunter and I really show that fact about class forcing in our geology paper? I don't recall doing so there. | |
| Dec 11, 2011 at 23:37 | vote | accept | mikeyus | ||
| Dec 11, 2011 at 22:49 | answer | added | Joel David Hamkins | timeline score: 16 | |
| Dec 11, 2011 at 21:20 | comment | added | mikeyus | As the above comments indicate that the answer is "no", let me add the following to my above question: Are there special cases where the answers is "yes"? This means that, although in full generality the ground model may fail to be definable after class forcing, I would still be interested in possible special types of class-forcing notions that indeed allow ground-model-definability in the extension. | |
| Dec 11, 2011 at 21:14 | comment | added | Asaf Karagila♦ | Andres: I didn't claim it was new, I think that the paper takes from one of the writers thesis (perhaps a stronger result). I just said that it is shown there. | |
| Dec 11, 2011 at 21:12 | comment | added | Andrés E. Caicedo | Asaf: But this was known years ago. I met Sy Friedman in 1995 in Bogota. When writing my undergraduate thesis (either at the end of 95 or the beginning of 96) I contacted him precisely about this problem, and he showed me an argument. | |
| Dec 11, 2011 at 20:26 | comment | added | Asaf Karagila♦ | Soon Joel David Hamkins will come and write a full answer (also, I have to leave shortly) it is shown in the paper "Set Theoretic Geology" that the answer is no. | |
| Dec 11, 2011 at 20:18 | history | asked | mikeyus | CC BY-SA 3.0 |