SUNDelta

Description

SUNDelta[a, b] is the Kronecker-delta for SU(N) with color indices a and b.

See also: ExplicitSUNIndex, SD, SUNF, SUNIndex, SUNSimplify, Trick.

Examples

SUNDelta[a, b]

Trick[ SUNDelta[a, b] SUNDelta[b, c] ]

SUNDelta[SUNIndex[a], SUNIndex[b]]

SUNDelta[a, b] // StandardForm

SUNDelta[a, b] // FCI // StandardForm

SUNDelta[a, b] // FCI // FCE // StandardForm

SD[a, b] // FCI // StandardForm

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.

SUNDelta[a, 2] SUNDelta[a, b] SUNDelta[c, 2] // SUNSimplify

% // StandardForm

SUNDelta[1, 2] // FCI // StandardForm