SU(3), U(1), O(3), etc what are they?

  • Thread starter cefarix
  • Start date
  • #1
74
0
I've heard them used before...some sort of symmetry, but I never figured out what it really is. Can someone please explain the concepts to me? thx
 

Answers and Replies

  • #3
HallsofIvy
Science Advisor
Homework Helper
41,847
966
SU(3) is the "special unitary group of order 3": 3 by 3 complex matrices with determinant 1

O(3) is the "orthogonal group of order 3": 3 by 3 real matrices with determinant 1 or -1

U(1) is a bit puzzling! I would interpret U(n) as the "unitary group of order 3": n by n complex matrices with determinant 1 or -1. But "1 by 1 matrices" are just numbers. I guess U(1) would be the multiplicative group with members 1, -1, i, and -i!
 
  • #4
334
1
You will here them used to describe different types of standard model features.

U(1) corresponds to photon
SU(2) to W's and Z's
SU(3) to the gluons.
 

Related Threads on SU(3), U(1), O(3), etc what are they?

Replies
6
Views
2K
  • Last Post
2
Replies
48
Views
145K
Replies
1
Views
2K
  • Last Post
Replies
4
Views
7K
Replies
10
Views
3K
Replies
2
Views
3K
  • Last Post
Replies
7
Views
749
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
7
Views
8K
Top