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FeynCalc / feyncalc

Mathematica package for algebraic calculations in elementary particle physics.
https://feyncalc.github.io
GNU General Public License v3.0
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Probelm in Trace in Feyncalc 9.2.0 #23

Closed sbilmis closed 7 years ago

sbilmis commented 7 years ago

Hi, In Feyncalc 9.0.0 when I tried to evaluate; (Mathematica 10.2.0.0 MacOS) Tr[DiracSigma[GA[a],GA[b]].GA[a].GA[b] I get -48i.

However when I tried the same command with FeynCalc 9.2.0 I get; (Mathematica 11.0.1.0 MacOS) tr(\sigma^{ab} . \gamma^a . \gamma^b) It does not evaluate but simply writes the output.

On the other hand, when I evaluate Tr[GA[a].GA[b]] I get the correct result.

It seems the problem is due to DiracSigma. Is there a change in the new version or am I missing some trivial things?

How can I solve it?

Thanks in advance.

Selcuk

vsht commented 7 years ago

Hi Selcuk,

this is an unfortunate omission that occurred while rewriting the internal logic of DiracTrace. Should be now fixed. Please reinstall FeynCalc 9.2 via the automatic installer.

Cheers, Vladyslav

sbilmis commented 7 years ago

That solved my problem.

Thank you.