Timeline for Can you define the absolute Galois groupoid in von Neumann–Bernays–Gödel set theory?
Current License: CC BY-SA 4.0
5 events
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| Dec 5, 2020 at 2:07 | comment | added | Noah Schweber | As to the question, I suspect that the standard definition (whatever it is - I can't find a satisfying reference, but this MO question mentions it) already works as a definition in $\mathsf{NBG}$ - of a large groupoid, of course - so that really all or almost all texts in number theory essentially do this by default. Scott's trick can then be used to canonically produce an equivalent small groupoid, so that we can freely switch to $\mathsf{ZFC}$ anytime we want. | |
| Dec 5, 2020 at 2:00 | comment | added | Noah Schweber | What does "without truncating cardinals" mean? Are you referring to Scott's trick? If so, why do you want to avoid it? It lets you formalize everything you want in $\mathsf{ZF}$ alone, with no need to talk about classes at all. | |
| Dec 4, 2020 at 19:42 | comment | added | Emil Jeřábek | Could you perhaps include the definition of the absolute Galois groupoid for the uninitiated? | |
| Dec 4, 2020 at 10:50 | review | First posts | |||
| Dec 4, 2020 at 11:29 | |||||
| Dec 4, 2020 at 10:43 | history | asked | BNG | CC BY-SA 4.0 |