IFPDOff[exp_, q1, q2, ...]
changes from IFPD
representation to FeynAmpDenominator[...]
. The q1, q2, ...
are the integration momenta.
[Momentum[p], m] IFPD
[Momentum[p], m] // StandardForm
IFPD
(*IFPD[Momentum[p], m]*)
= IFPDOff[IFPD[Momentum[p], m], p] ex
// StandardForm
ex
(*-m^2 + Pair[Momentum[p], Momentum[p]]*)