Program for Traces of Dirac matrices

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Discussion Overview

The discussion revolves around calculating traces of Dirac matrices using computational tools, specifically focusing on the limitations of the FeynCalc package in Mathematica and seeking alternative solutions or methods for these calculations.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Exploratory

Main Points Raised

  • One participant expresses frustration with FeynCalc's output, which is described as unreadable and lacking support for changing the metric to (-1,1,1,1).
  • Another participant echoes the initial concern about the usability of FeynCalc and seeks alternative programs or packages for calculating traces of Dirac matrices.
  • A participant unfamiliar with Dirac matrices questions the validity of using the property $Tr(A\otimes B) = Tr(A)Tr(B)$ in this context, suggesting a potential misunderstanding of the application.
  • Further elaboration on the possibility of implementing Dirac algebra functions in Mathematica is mentioned, but the preference remains for using existing tools like FeynCalc.
  • Links to external resources are provided, which may offer additional insights or tools relevant to the calculations.

Areas of Agreement / Disagreement

Participants generally agree on the limitations of FeynCalc but do not reach a consensus on alternative solutions or the appropriateness of certain mathematical properties in this context. The discussion remains unresolved regarding the best approach to calculating traces of Dirac matrices.

Contextual Notes

Participants express uncertainty about the functionality of existing tools and the mathematical properties applicable to Dirac matrices, indicating a need for clarification on these points.

PJK
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Hi all,

I want to calculate traces of Dirac matrices with a program like Mathematica.
I found the package FeynCalc but it seems to be outdated.
It is always producing results like this:
Code:
4 (-(DiracCanonical->False) (Factoring->False) (FeynCalcInternal->True) g^(mu nu) 

(InsideDiracTrace->True) k\[CenterDot]l-l^2 (DiracCanonical->False) (Factoring->False) 

(FeynCalcInternal->True) g^(mu nu) (InsideDiracTrace->True)+m^2 

(DiracCanonical->False) (Factoring->False) (FeynCalcInternal->True) g^(mu nu) 

(InsideDiracTrace->True)+k^nu l^mu (DiracCanonical->False) (Factoring->False) 

(FeynCalcInternal->True) (InsideDiracTrace->True)+k^mu l^nu (DiracCanonical->False) 

(Factoring->False) (FeynCalcInternal->True) (InsideDiracTrace->True)+2 l^mu l^nu 

(DiracCanonical->False) (Factoring->False) (FeynCalcInternal->True) 

(InsideDiracTrace->True))
Which is quite annoying. Even worse I want to use the metric (-1,1,1,1) and there seems to be no support for changing the metric.
Is there a better program/package for doing those calculations?
 
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Apparently this was a difficult question. But maybe one year later someone has got an idea?
I have the same problem as the one described above.
 
comote said:
I am not too(edit: At all) familiar with the Dirac matrices but following the discussion on

http://mathworld.wolfram.com/DiracMatrices.html

What is wrong with using $Tr(A\otimes B) = Tr(A)Tr(B)$?

Thanks for your input. Of course it would be possible to implement all the Dirac algebra using the functions of Mathematica. That's what the people of FeynCalc did. But since it has already been done, I would rather use it, instead of redoing it myself. And FeynCalc DOES work; its output is just unreadable (as can be seen in the example above).
 

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