SPLP
SPLP[p,q,n,nb]
denotes the positive component in the lightcone decomposition of the scalar product p⋅q along the vectors n
and nb
. It corresponds to 21(p⋅n)(q⋅nˉ).
If one omits n
and nb
, the program will use default vectors specified via $FCDefaultLightconeVectorN
and $FCDefaultLightconeVectorNB
.
See also
Overview, Pair, FVLN, FVLP, FVLR, SPLN, SPLR, MTLP, MTLN, MTLR.
Examples
21(n⋅p)(nb⋅q)
StandardForm[SPLP[p, q, n, nb] // FCI]
21Pair[Momentum[n],Momentum[p]]Pair[Momentum[nb],Momentum[q]]
Notice that the properties of n
and nb
vectors have to be set by hand before doing the actual computation
SPLP[p1 + p2 + n, q, n, nb] // ExpandScalarProduct
21(nb⋅q)(n⋅p1+n⋅p2+n2)
FCClearScalarProducts[]
SP[n] = 0;
SP[nb] = 0;
SP[n, nb] = 2;
SPLP[p1 + p2 + n, q, n, nb] // ExpandScalarProduct
21(nb⋅q)(n⋅p1+n⋅p2)