1

I am new to Feyncalc and I am facing the following problem. I am doing the following: I set q3=-q2-q1;

Then I write

Pair[LorentzIndex[k], 
Momentum[q3]] - (-Pair[LorentzIndex[k], Momentum[q2]] - 
 Pair[LorentzIndex[k], Momentum[q1]])) // DiracReduce

and I get 

FV[q1, k] + FV[-q1 - q2, k] + FV[q2, k]

Now if I multiply the above with a gamma matrix, let's say for instance GA5 i.e.

 (Pair[LorentzIndex[k], 
Momentum[q3]] - (-Pair[LorentzIndex[k], Momentum[q2]] - 
 Pair[LorentzIndex[k], Momentum[q1]])))GA5 // DiracReduce

I get zero as I am supposed to find.

Is this is bug? I cannot make the first expression equal to zero. And similar things happen with more complicated expressions.

ciao
  • 25,774
  • 2
  • 58
  • 139
gekatsia
  • 11
  • 1
  • 3
    Welcome to the Mathematica SE. Please note, the use of the Bugs tag is only for confirmed bugs, that is, where a possible bug is confirmed by other community members and a consensus is reached. Please do not use that tag for suspected bugs.

    In addition, while you might get an answer from the community re: FeynCalc here, in general this is for discussion of the products from Wolfram Research.

    For third-party tools/add-ons, you are generally better served in their respective fora, in this case the FeynCalc forum at https://feyncalc.github.io/forum

     – ciao Sep 30 '19 at 04:39
  • You can use // Calc to simplify it. – QuantumDot Sep 30 '19 at 16:59

0 Answers0