Timeline for Prime/undecomposable matrices
Current License: CC BY-SA 2.5
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 27, 2010 at 14:11 | comment | added | Pete L. Clark | I'm a bit confused as to why this is the accepted answer. The question is about free monoids and this answer discusses not necessarily free groups. | |
| May 27, 2010 at 12:13 | comment | added | Unknown | Right! I was a bit hasty. Not "the field of naturals" just the naturals. | |
| May 27, 2010 at 11:54 | vote | accept | Unknown | ||
| Jun 14, 2010 at 15:22 | |||||
| May 27, 2010 at 11:28 | comment | added | coudy | @Victor. My question was not addressing if the decomposition holds in higher dimension, but if it holds for fuchsian groups, for example for the subgroups of $SL_2(Z)$ obtained from the congruence subgroups. Let me be more specific. You can't have such decomposition for the derived subgroup of the principal congruence subgroup of level 2 because that group is infinitely generated. Sorry for not being clear. | |
| May 27, 2010 at 9:12 | comment | added | Victor Protsak | You are missing the point: OP's matrices have $\textit{non-negative}$ entries (even if he mistakenly spoke of "FIELD of naturals"), and in semigroups, almost nothing works in the same way as in groups. E.g. there was a recent MO discussion of the fact that non-negative integer matrices for $n\geq 3$ are not f.g. | |
| May 27, 2010 at 9:05 | history | answered | coudy | CC BY-SA 2.5 |