Timeline for Solving algebraic problems with topology
Current License: CC BY-SA 4.0
6 events
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| Jul 3, 2020 at 15:32 | comment | added | Omar Antolín-Camarena | Hi @HenrikRüping! Thanks for that argument. As you know, for me the theory of graphs of groups is more exotic than classifying spaces, but I really should learn it some day. :P | |
| Jul 3, 2020 at 7:38 | comment | added | HenrikRüping | Hi, this also follows from the theory of graphs of groups. Take the canonical action of $G_1*G_2$ of a tree and restrict it to Ker(f). Now we need to compute the quotient graph of groups, which has two vertices with stabilizer groups $K_1$ and $K_2$ and $H$ edges connecting them. Then the fundamental theorem for graphs of groups tells us that $Ker(f)$ can be obtained as the fundamental group of that graph of groups, e.g. it is exactly given as above. | |
| Jul 3, 2020 at 2:21 | history | edited | Omar Antolín-Camarena | CC BY-SA 4.0 |
added 498 characters in body
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| Jul 3, 2020 at 2:00 | history | edited | Omar Antolín-Camarena | CC BY-SA 4.0 |
fix bad typo: pullback -> pushout
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| S Jul 3, 2020 at 1:51 | history | answered | Omar Antolín-Camarena | CC BY-SA 4.0 | |
| S Jul 3, 2020 at 1:51 | history | made wiki | Post Made Community Wiki by Omar Antolín-Camarena |