Name: V. Shtabovenko Date: 01/21/20-05:34:35 PM Z


Eps is an internal object (FCI), so what you write
is interpreted as

Eps[Momentum[0],…] which is indeed zero.

What you obviously mean is LC[0,1,2,3] which
is of course not zero (but FeynCalc’s also doesn’t
insert an explicit value). As you can see from

LC[0, 1, 2, 3] // FCI // StandardForm

eps^0123 is translated to

Eps[ExplicitLorentzIndex[0], ExplicitLorentzIndex[1],
  ExplicitLorentzIndex[2], ExplicitLorentzIndex[3]]

Cheers,
Vladyslav

Am 21.01.20 um 16:25 schrieb Juan Nieves:
> FeynCalc 9.3.0 (stable version).
>
>
> In[34]:= Eps[0, 1, 2, 3]
>
> Out[34]= 0
>
> I simply do not understand.
>
> Juan M Nieves
>