FCPartialD[ind]
denotes a partial derivative of a field. It is an internal object that may appear only inside a QuantumField
.
FCPartialD[LorentzIndex[mu]]
denotes .
FCPartialD[LorentzIndex[mu ,D]]
denotes the -dimensional .
FCPartialD[CartesianIndex[i]]
denotes .
If you need to specify a derivative with respect to a particular variable it also possible to use FCPartialD[{LorentzIndex[mu],y}]
or FCPartialD[{CartesianIndex[i],x}]
although this notation is still somewhat experimental
Overview, ExpandPartialD, LeftPartialD, LeftRightPartialD, RightPartialD.
[A, {\[Mu]}] . LeftPartialD[\[Nu]]
QuantumField
= ExpandPartialD[%] ex
// StandardForm
ex
(*QuantumField[FCPartialD[LorentzIndex[\[Nu]]], A, LorentzIndex[\[Mu]]]*)
[{CartesianIndex[i], x}] . QuantumField[S, x]
RightPartialD
= ExpandPartialD[%] ex
// StandardForm
ex
(*QuantumField[FCPartialD[{CartesianIndex[i], x}], S, x]*)
FCPartialD
also accepts FCGV
symbols as arguments, which can be sometimes useful to make the final expression look nicer.
[FCPartialD[FCGV["\[Del]"]], S, x] QuantumField