CVD[p, i]
is a D-1-dimensional Cartesian vector and is transformed into CartesianPair[CartesianMomentum[p,D], CartesianIndex[i,D]]
by FeynCalcInternal
.
Overview, FVD, Pair, CartesianPair.
[p, i] CVD
p^i
[p - q, i] CVD
(p-q)^i
[CVD[p, i]] // StandardForm
FCI
(*CartesianPair[CartesianIndex[i, -1 + D], CartesianMomentum[p, -1 + D]]*)
ExpandScalarProduct
is used to expand momenta in CVD
[CVD[p - q, i]] ExpandScalarProduct
p^i-q^i