- #1
Hymne
- 89
- 1
Hello!
I´m currently reading 'Groups, Representations and Physics' by H.F. Jones and I have drawn some conclusions that I would like to have confirmed + I have some questions. :)
Conclusions:
1. An albelian group has always only one irrep.
2. The direct sum of two representations can be thought of as a matrix on block diagonal form, in which we have one block to each group.
Questions:
1. Jones says that the number of irreps is equal to the numer of conjugacy classes, r = k. But SO(2) is an abelian group so r = 1, but every element is its own conjugacy class since g q g^(-1) = gg^(-1) q = q, so k = infinity?
2. If conclusion 2 is right, how should i think of the matrixrepresentation for a direct product group, say SO(2)xSO(2)?
Maybe some conclusions and questions will be added in the nearby future but this is it for the moment.
Thanks helping!
// Hymne
I´m currently reading 'Groups, Representations and Physics' by H.F. Jones and I have drawn some conclusions that I would like to have confirmed + I have some questions. :)
Conclusions:
1. An albelian group has always only one irrep.
2. The direct sum of two representations can be thought of as a matrix on block diagonal form, in which we have one block to each group.
Questions:
1. Jones says that the number of irreps is equal to the numer of conjugacy classes, r = k. But SO(2) is an abelian group so r = 1, but every element is its own conjugacy class since g q g^(-1) = gg^(-1) q = q, so k = infinity?
2. If conclusion 2 is right, how should i think of the matrixrepresentation for a direct product group, say SO(2)xSO(2)?
Maybe some conclusions and questions will be added in the nearby future but this is it for the moment.
Thanks helping!
// Hymne