DiracSigma
DiracSigma[a, b]
stands for I/2(a.b−b.a) in 4 dimensions.
a
and b
must have head DiracGamma
, GA
or GS
. Only antisymmetry is implemented.
See also
Overview, DiracSigmaExplicit.
Examples
DiracSigma[GA[\[Alpha]], GA[\[Beta]]]
DiracSigmaExplicit[%]
σαβ
21i(γˉα.γˉβ−γˉβ.γˉα)
DiracSigma[GA[\[Beta]], GA[\[Alpha]]]
−σαβ
DiracSigma[GS[p], GS[q]]
DiracSigmaExplicit[%]
σpq
21i((γˉ⋅p).(γˉ⋅q)−(γˉ⋅q).(γˉ⋅p))
The antisymmetry property is built-in
DiracSigma[GA[\[Alpha]], GA[\[Alpha]]]
0