Name: Vladyslav Shtabovenko Date: 07/13/15-11:40:33 AM Z
Hi,
this is indeed an issue with memoization inside SUNSimplify and
patterns. I’ll fix it as soon as I can (at the moment I’m a bit busy
with non-FeynCalc related work)
Cheers,
Vladyslav
Am 12.07.2015 um 21:30 schrieb tomas00100100:
> Hello everyone! I need to automatically calculate traces of
products of (for example) three Gell-Mann matrices:
>
>
SUNTrace[SUNT[SUNIndex[a]].SUNT[SUNIndex[b]].SUNT[SUNIndex[c]]]
>
> so I wrote a rule in FeynCalc that changes the trace to its explicit
form:
>
> rule =
{SUNTrace[SUNT[SUNIndex[a_]].SUNT[SUNIndex[b_]].SUNT[SUNIndex[c_]]]
:> 1/4 (SUND[SUNIndex[a], SUNIndex[b],
SUNIndex[c]]+I SUNF[SUNIndex[a],
SUNIndex[b], SUNIndex[c]])};
>
> Obviously, this gives the correct answer for
>
>
SUNTrace[SUNT[SUNIndex[a]].SUNT[SUNIndex[b]].SUNT[SUNIndex[c]]]
//. rule
>
> BUT whenever I try another input, such as
>
>
SUNTrace[SUNT[SUNIndex[x]].SUNT[SUNIndex[y]].SUNT[SUNIndex[z]]]
//. rule
>
> I get a result with indices with underscores, such as
>
> 1/4 (SUND[SUNIndex[x_], SUNIndex[y_],
SUNIndex[z_]]+I SUNF[SUNIndex[x_],
SUNIndex[y_], SUNIndex[z_]])
>
> I do not know why this is happening but it bugs me because this rule
worked for me pretty well in past days and now it just doesn’t work.
Moreover, it is impossible to carry out the next calculations when the
indices carry the underscores. Thanks everyone for helping me.
>