Timeline for Second homology group of a presentation complex
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 22, 2022 at 15:59 | comment | added | Denis T | You can read a lot about presentation complexes from the book "Combinatorial group theory" by Lyndon&Schupp. (That text is a great starting point for anyone trying to learn low-dimensional topology from algebraic point of view!) | |
| Sep 22, 2022 at 10:44 | comment | added | Carl-Fredrik Nyberg Brodda | @BenjaminSteinberg Ah, thanks! That's what I was missing. | |
| Sep 22, 2022 at 10:23 | comment | added | Benjamin Steinberg | To get the Schur multiplier you need at least the 3-skeleton of a classifying space | |
| Sep 22, 2022 at 9:46 | review | Close votes | |||
| Oct 17, 2022 at 3:04 | |||||
| Sep 22, 2022 at 9:29 | comment | added | Fernando Muro | The presentation complex has dimension at most 2 and the 2-dimensional homology of a 2-dimensional complex with coefficients in the integers is always free. | |
| Sep 22, 2022 at 9:20 | comment | added | Carl-Fredrik Nyberg Brodda | Maybe I'm being silly, but isn't this just the Schur multiplier for $G$? In this case, the answer to 1 is no -- the Schur multiplier of $C_2 \times C_2$ is $C_2$ (as is the Schur multiplier for $S_n$ with $n>3$, I believe). | |
| Sep 22, 2022 at 9:15 | history | edited | gola vat | CC BY-SA 4.0 |
added 159 characters in body
|
| S Sep 22, 2022 at 9:07 | review | First questions | |||
| Sep 22, 2022 at 11:00 | |||||
| S Sep 22, 2022 at 9:07 | history | asked | gola vat | CC BY-SA 4.0 |