SUNDelta[a, b] is the Kronecker-delta for SU(N) with color indices a and b.
See also: ExplicitSUNIndex, SD, SUNF, SUNIndex, SUNSimplify, Trick.
Symbolic arguments to SUNDelta are transformed into the data type SUNIndex and integer arguments are transformed to ExplicitSUNIndex. The difference is that SUNSimplify will only sum over symbolic indices.
|The FeynCalc Book||SUND||SUNF|