Name: rolf_at_HIDDEN-E-MAIL Date: 03/16/04-10:08:21 AM Z


Hi,
there is no need to use IdentityMatrix[4].

This:

Tr[FourVector[k1 + k2, μ].(GA[α] FourVector[k1, α] +
     m).(GA[μ] f1 - m (GA[μ, ν] -
GA[ν, μ]).FourVector[k1 - k2, ν] f2).(GS[k1] + m)]

should return

4*(2*f1*m*Pair[Momentum[k1],
    Momentum[k1]] +
  2*f1*m*Pair[Momentum[k1],
    Momentum[k2]])

--
Rolf Mertig