Name: Vladyslav Shtabovenko Date: 08/13/15-09:50:33 PM Z


This is what TensorFunction is for

TH[x_, y_] := TensorFunction[{Theta, “A”}, x, y]

TH[a, b] + TH[b, a]

gives 0. Same for

Contract[TH[a, b] MT[a, b]]

or

Contract[TH[a, b] FV[p, a] FV[p, b]]

For

Contract[TH[a, b] FV[p, a] FV[q, b] - TH[a, b] FV[p, b] FV[q, a]]

you get 2 Theta[Momentum[p], Momentum[q]]

The only inconvenience is that a contraction of an antisymmetric tensor
with a symmetric one doesn’t vanish automatically.

Cheers,
Vladyslav

> Dear All
>
> I am doing one scattering calculation by trace method. I need to define two index antisymmetric Lorentz tensor(\theta_{\mu \nu}. where \mu,\nu..1..4) in my code.
>
> I am not able to figure out how one can do it in feyncalc…Please help!!
>
> thanks