- #176
Hurkyl
Staff Emeritus
Science Advisor
Gold Member
- 14,981
- 26
Just to let everyone know, I probably won't be able to think about this for a while.
Originally posted by Lonewolf
Oh dear. lol. I'm quitting work this Friday, so I'll have time to give the topic the attention it needs. Be glad to hear your input when you return, Hurkyl. Always nice to have two people explaining something.
Originally posted by Lonewolf
Do as you see fit. I'm kinda struggling to get to grips with representations, ...
I'll leave it as an exercise that, for A in SU(2), the mapping:
(Af)(y, z) -> f(A-1(y, z))
is a linear invertible mapping, and that A(Bf) = (AB)f...
u v
-v* u*
u* -v
v* u
Originally posted by Hurkyl
I'll leave it as homework problem to prove that this is an irreducible representation (since I don't see right away how to prove it! )
Did not mean to hog the exposition like this! It was really Hurkyl's turn to talk but I got carried away. Sorry.
/ 0 0 0 \
[b]i[/b] = | 0 0 -1 |
\ 0 1 0 /
/ 0 0 1 \
[b]j[/b] = | 0 0 0 |
\ -1 0 0 /
/ 0 -1 0 \
[b]k[/b] = | 1 0 0 |
\ 0 0 0 /
[b]i[/b] = 0.5 / i 0 \
\ 0 -i /
[b]j[/b] = 0.5 / 0 1 \
\ -1 0 /
[b]k[/b] = 0.5 / 0 i \
\ i 0 /
rutwig said:Good (introductory) references are:
M. A. Armstrong. Groups and symmetry. Springer Verlag 1988.
Hurkyl said:On my computer, all of those are just roman letters drawn in a fancy way, not greek letters...