Name: Mikkel Bjoern Date: 12/17/15-10:09:19 AM Z
I have a contraction of three traces, for which the result depends on my naming of indices that are contracted out completely. I suspect the issue is with two-character issues, but I am not sure. And now, of course, I am unsure which result is right.
The two expressions are:
-- code ———————————
Tmu1 =
c1*Tr[GS[pm].GA[\[Mu]].GA[\[Nu]].GS[p].GA[\[Nu]m].GA[\[Mu]m]]
and the same, but where I exchange all “\[Nu]m” with “\[Alpha]” - producing EXTRA TERMS in the final trace (that do not simplify to zero, at least not according to Mathematica). Thus the code is
-– code ——————————-
Tmu1 = c1*
Tr[GS[pm].GA[\[Mu]].GA[\[Nu]].GS[p].GA[\[Alpha]].GA[\[Mu]m]]
Since I suspceted the two-character index might be an issue I tried renaming all “\[Nu]m”’s to “\[Alpha]” and all “\[Mu]m”’s to “\[Beta]” - for which THE RESULT AGREES WITH THE ORIGINAL, that is, without the extra term.
Does anyone have an idea what is going on? I guess it is some kind of bug, since names of contracted indices should obviously now matter.
However I am new to Feyncal and could be doing something wrong.
Thank you!
Mikkel