Timeline for 'Almost-isomorphic' groups
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 9, 2014 at 21:53 | comment | added | Martin Brandenburg | ... and one could also take (so-called) direct sums of groups, add boring factors, etc. | |
| Jan 28, 2013 at 5:03 | comment | added | Khalid Bou-Rabee | I believe you can modify the example so that the direct products become semidirect products. | |
| Jan 22, 2013 at 16:00 | comment | added | Stefan Kohl♦ | The examples given so far are of the form $(A \times B^\infty, B^\infty)$, where $A$ both embeds into $B$ and is an epimorphic image of $B$. -- Can anyone give an example where the groups do not admit a decomposition into infinitely many direct factors, or which are at least not of the form $(A \times B^\infty, B^\infty)$? | |
| Jan 22, 2013 at 9:41 | comment | added | Martin Brandenburg | @Berlusconi: I am not a group theorist, but my impression is that it is too optimistic to hope for a classification (without further assumptions and special conditions). | |
| Jan 18, 2013 at 15:00 | comment | added | Stefan Kohl♦ | Indeed. -- However which one is 'simpler' depends on your notion of 'simplicity': in order to define a free group, you need no relations, while to define a finite cyclic group, you need 1! | |
| Jan 18, 2013 at 14:53 | comment | added | S. Carnahan♦ | A slightly simpler example: $C_2 \times C_4^\infty$ and $C_4^\infty$. | |
| Jan 18, 2013 at 11:39 | history | asked | Stefan Kohl♦ | CC BY-SA 3.0 |