PauliSigmaExpand
PauliSigmaExpand[exp]
expands all PauliSigma[Momentum[a+b+..]]
in exp
into (PauliSigma[Momentum[a]] + PauliSigma[Momentum[b]] + ...)
.
See also
Overview, PauliSigmaCombine.
Examples
SIS[q] . SIS[p - q]
PauliSigmaExpand[%]
(σˉ⋅q).(σˉ⋅(p−q))
(σˉ⋅q).(σˉ⋅p−σˉ⋅q)
SIS[a + b] . SIS[c + d]
PauliSigmaExpand[%, Momentum -> {a}]
PauliSigmaExpand[%%, Momentum -> All]
(σˉ⋅(a+b)).(σˉ⋅(c+d))
(σˉ⋅a+σˉ⋅b).(σˉ⋅(c+d))
(σˉ⋅a+σˉ⋅b).(σˉ⋅c+σˉ⋅d)