GS
GS[p]
can be used as input for a 4-dimensional pμγμ and is transformed into DiracGamma[Momentum[p]]
by FeynCalcInternal
(=FCI
).
GS[p,q, ...]
is a short form for GS[p].GS[q]
.
See also
Overview, DiracGamma, GA, GAD.
Examples
γˉ⋅p
GS[p] // FCI // StandardForm
(*DiracGamma[Momentum[p]]*)
(γˉ⋅p).(γˉ⋅q).(γˉ⋅r).(γˉ⋅s)
GS[p, q, r, s] // StandardForm
(*GS[p] . GS[q] . GS[r] . GS[s]*)
GS[q] . (GS[p] + m) . GS[q]
(γˉ⋅q).(γˉ⋅p+m).(γˉ⋅q)