Skip to main content

Timeline for Is SO(4) a subgroup of SU(3)?

Current License: CC BY-SA 4.0

4 events
when toggle format what by license comment
Nov 23, 2021 at 21:06 history edited Tom Goodwillie CC BY-SA 4.0
added 2 characters in body
Nov 20, 2021 at 16:17 comment added YCor However, this argument doesn't directly show that $\mathrm{SU}(2)^2$ doesn't embed into $\mathrm{SU}(3)$.
Nov 20, 2021 at 16:12 comment added YCor Indeed, I had mentioned with exactly this argument that $\mathrm{SO}(5)$ doesn't embed in $\mathrm{SU}(4)$, but this applies equally to show that for no $n\ge 2$, $\mathrm{SO}(n)$ embeds into $\mathrm{SU}(n-1)$. Namely, for both $\mathrm{SO}(n)$ and $\mathrm{SU}(n)$ (and $\mathrm{SL}_n$ over any field of char$\neq 2$), for $n\ge 1$, the maximal order of a 2-elementary abelian group is $2^{n-1}$.
Nov 18, 2021 at 16:03 history answered Tom Goodwillie CC BY-SA 4.0