- #36
selfAdjoint
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That account might be a little confusing unless you know that in QCD, each gluon carries two charges, one of the colors and one of the anticolors. Each gluon is represented by a 3X3 matrix, in a representation of the gauge group SU(3). Rows correspond to the color charges and columns to the anti-color ones. Since there are three choices for each of these, the number of possibilities would seem to be 3X3 = 9. But the requirement that the matrices representing the gluons be unitary means you can derive algebraic relations from which given any eight components you can calculate the ninth. So there are really only eight INDEPENDENT components of the 3X3 gluon matrix.