What is the center of SU(3) group

[sufive]

Dear Every One,

In literatures on QCD confinement, I usually see the words ``center of group''.
It is defined to be the subgroup of some parent group and consists of elements which
commutes with all elements from the parent group. But what is the center of SU(3)
group? I need concrete answer as follows instead formal definition,

For SU(2) group, fundamental representation, the center consists the following
two matrices
c1=diag{1,1}, c2=diag{-1,-1}

What is the case for SU(3) group, fundamental representation?

Thank you very much!

 

[fzero]

The center of SU(n) is \mathbb{Z}_n. It is generated by

C = \alpha I_n,

where \alpha = \exp(2\pi i/n) is an n^\text{th} root of unity. Note that for n=2, \alpha= -1, so we have elements I, -I.