SPE[a, b]
denotes a -dimensional scalar product. SPE[a, b]
is transformed into Pair[Momentum[a, -4 + D], Momentum[b, -4 + D]]
by FeynCalcInternal
.
SPE[p]
is the same as SPE[p,p]
.
Overview, PD, Calc, ExpandScalarProduct, ScalarProduct, SPD.
[p, q] + SPE[q] SPE
[p - q, q + 2 p] SPE
[ SPE[p - q, q + 2 p] ] Calc
[SPE[p - q]] ExpandScalarProduct
[a, b] // StandardForm
SPE
(*SPE[a, b]*)
[a, b] // FCI // StandardForm
SPE
(*Pair[Momentum[a, -4 + D], Momentum[b, -4 + D]]*)
[a, b] // FCI // FCE // StandardForm
SPE
(*SPE[a, b]*)
[ChangeDimension[SP[p, q], D - 4]] // StandardForm
FCE
(*SPE[p, q]*)