Name: Masaru Watanabe Date: 08/17/11-09:35:13 AM Z
I have tested the DiracTrace example in Guide to FeynCalc 1.0 which
worked correctly on Mathematica 5 but did not give the same answer
on Mathematica 8. I tested on Windows Vista. For Mma5:
In[_]:= T[n_] := T[n] = Block[{gamma,
calc},
gamma = Dot @@ Table[DiracMatrix[a[i],
Dimension -> (d - 4)], {i, 1, n}];
calc = Timing[Tr[gamma.gamma]];
Print[“Time=”, calc[[1]] //
FeynCalcForm];
calc[[2]]];
In[_]:= T[3]
Time=0.Second
Out[_]= -4(d-4)(d^2-14d+44)
But On Mma8:
Out[_]= 4Overscript[\[Gamma],
^]^a(1).Overscript[\[Gamma],
^]^a(2).Overscript[\[Gamma],
^]^a(3).Overscript[\[Gamma],
^]^a(1).Overscript[\[Gamma],
^]^a(2).Overscript[\[Gamma], ^]^a(3)
Is this correct answer?