Timeline for Extending primitive systems in free groups
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
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| Mar 4 at 2:33 | comment | added | Andy Putman | (for $n=2$ it just consists of inner automorphisms, so it isn’t very interesting) | |
| Mar 4 at 2:32 | comment | added | Andy Putman | @Carl-FredrikNybergBrodda: It’s known to not be finitely presented for $n=3$ by a theorem of Krstic-McCool, but this is totally open for higher $n$. | |
| Mar 4 at 1:58 | comment | added | Carl-Fredrik Nyberg Brodda | Nice collection of results! Is it known whether the Torelli subgroup is finitely presented? | |
| Mar 3 at 22:29 | comment | added | Andy Putman | @HJRW: Whoops, you're right! That's what happens when you type quickly... | |
| Mar 3 at 22:29 | history | edited | Andy Putman | CC BY-SA 4.0 |
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| Mar 3 at 22:21 | comment | added | HJRW | I guess you meant to say that Magnus proved that $ \mathrm{IA}_n$ is finitely generated? | |
| Mar 3 at 20:43 | comment | added | Andy Putman | @SamHopkins: That's a good point, but there is more structure to the $c$ where it is a partial basis. And determining one is equivalent to determining the other. | |
| Mar 3 at 20:43 | history | edited | verret | CC BY-SA 4.0 |
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| Mar 3 at 20:42 | comment | added | Sam Hopkins | They're two sides of the same coin, but it seemed to me that the question-asker was trying to find $c$ for which $\{x_1,\ldots,x_k,x_{k+1}c\}$ is not a partial basis. | |
| Mar 3 at 20:39 | history | answered | Andy Putman | CC BY-SA 4.0 |