Timeline for "Rocket elements" in bijections $f:\mathbb{N}\to \mathbb{N}$
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
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| Jul 15, 2019 at 2:32 | answer | added | Aaron Meyerowitz | timeline score: 3 | |
| Jul 14, 2019 at 20:15 | comment | added | Matemáticos Chibchas | @AsafKaragila Actually I would write $f^{[n]}(k)$. | |
| Jul 14, 2019 at 18:08 | history | edited | YCor |
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| Jul 14, 2019 at 18:08 | comment | added | YCor | (Yet in the wobbling group the sup (of the bonus question) is $1$, by an easy argument.) | |
| Jul 14, 2019 at 16:51 | comment | added | YCor | If you restrict to the wobbling group, that is, the group of permutations $f$ of $\mathbb{N}$ such that $\sup_n|f(n)-n|<\infty$, the trivial counterexample fails and there's no $f$ with the given condition, I think. | |
| Jul 14, 2019 at 16:50 | comment | added | Asaf Karagila♦ | And with a slight misuse of notation, too. Normally you'd write $f^n(k)$, I've only seen $f^{(n)}$ in the context of the $n$th derivative. | |
| Jul 14, 2019 at 16:48 | comment | added | YCor | The beginning is just redefining powers in the monoid of self-maps of $\mathbb{N}$. | |
| Jul 14, 2019 at 16:17 | vote | accept | Dominic van der Zypen | ||
| Jul 14, 2019 at 15:45 | answer | added | Martin Sleziak | timeline score: 19 | |
| Jul 14, 2019 at 15:25 | history | asked | Dominic van der Zypen | CC BY-SA 4.0 |