Timeline for How many models of Peano arithmetic are isomorphic to the standard model and how many models of Peano arithmetic are non-standard?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Dec 18, 2023 at 15:46 | comment | added | Joel David Hamkins | @MikhailKatz That is interesting. I'd suggest you specify exactly what you mean by "hyperreals" e.g. what is the language, what is the theory, which models, etc. and also in the general case what counts as hypernaturals, etc. | |
| Apr 20, 2021 at 7:09 | comment | added | Joel David Hamkins | Yes. There are $2^{\omega_1}$ many distinct $\omega_1$-like models of PA (and of ZFC), as explained in this article: jdh.hamkins.org/…. | |
| Apr 20, 2021 at 5:24 | comment | added | Vladimir Reshetnikov | Is it possible to count (up to isomorphism) models of PA of a higher cardinality, say, $\aleph_1$ or $\mathfrak c$? | |
| Mar 24, 2012 at 23:02 | vote | accept | Samuel Reid | ||
| Mar 24, 2012 at 23:02 | comment | added | Samuel Reid | @JoelDavidHamkins: This answer is very helpful! Thank you! | |
| Mar 24, 2012 at 21:16 | history | answered | Joel David Hamkins | CC BY-SA 3.0 |