FeynCalc manual (development version)

GS

GS[p] can be used as input for a 4-dimensional pμγμp^\mu \gamma_\mu 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

GS[p]

γˉp\bar{\gamma }\cdot \overline{p}

GS[p] // FCI // StandardForm

(*DiracGamma[Momentum[p]]*)
GS[p, q, r, s]

(γˉp).(γˉq).(γˉr).(γˉs)\left(\bar{\gamma }\cdot \overline{p}\right).\left(\bar{\gamma }\cdot \overline{q}\right).\left(\bar{\gamma }\cdot \overline{r}\right).\left(\bar{\gamma }\cdot \overline{s}\right)

GS[p, q, r, s] // StandardForm

(*GS[p] . GS[q] . GS[r] . GS[s]*)
GS[q] . (GS[p] + m) . GS[q]

(γˉq).(γˉp+m).(γˉq)\left(\bar{\gamma }\cdot \overline{q}\right).\left(\bar{\gamma }\cdot \overline{p}+m\right).\left(\bar{\gamma }\cdot \overline{q}\right)