Name: Vladyslav Shtabovenko Date: 07/02/15-06:27:46 PM Z


Hmm, are you using the latest snapshot from the repository? Are
there any other packages loaded with FeynCalc?

I tried to reproduce this on Mathematica 10.1 (Linux version) but
somehow I can’t see the behavior that you observe

FI;

DiracTrace[GA[\[Mu]].GA[\[Nu]]]

-> DiracTrace[GA[\[Mu]].GA[\[Nu]]]

DiracTrace[GA[\[Mu]].GA[\[Nu]],DiracTraceEvaluate->True]

-> 4*Pair[LorentzIndex[\[Mu]], LorentzIndex[\[Nu]]]

Tr[GA[\[Mu]].GA[\[Nu]]]

-> 4*Pair[LorentzIndex[\[Mu]], LorentzIndex[\[Nu]]]

Cheers,
Vladyslav

Am 02.07.2015 um 12:50 schrieb Sun Qingfeng:
> I see, Thanks for the detailed reply.
>
> BTW, when I test the FC9.0, I am confused by the output:
> Input:
> DiracTrace[GA[\[Mu]].GA[\[Nu]]]
>
> Output:
> Factoring[4 Pair[LorentzIndex[\[Mu]], LorentzIndex[\[Nu]]]]
>
> In the previous version(8.20) the output seems to be:
> 4 Pair[LorentzIndex[\[Mu]], LorentzIndex[\[Nu]]]
> My Mathematica version is 10.1
>