Name: Vladyslav Shtabovenko Date: 02/10/15-07:55:16 PM Z


Dear Nodoka,

it is definitely on my ToDo list to improve SUNSimplify and SUNTrace.
I’ll see how much effort is needed to add the relations you mentioned.

Cheers,
Vladyslav

On 09/02/15 14:05, Nodoka Yamanaka wrote:
> Dear Developer,
>
> Hello,
>
> In the use of SUND, I was aware that the formula for the reduction of the triple product of symmetric tensors
> d_{iab} d_{jbc} d_{kca} = (N/2 - 6/N) d_{ijk}
> and
> that for the quadruple product
> d_{iab} d_{jbc} d_{kcd} d_{lda} = ( 1 - 4/N^2 ) (delta_{ij} delta_{kl} +delta_{il} delta_{jk} ) + ( N/4 - 4/N )( d_{ijr} d_{klr} + d_{ilr} d_{jkr} ) - ( N/4 ) d_{ikr} d_{jlr}
> are lacking.
> (d_{ijk} is the symmetric tensor SUND[i,j,k] and delta_{ij} the Kronecker delta symbol).
> Is it possible to add them in the formula of FeynCalc so that SUNSimplify can also reduce expressions involving them?
>
> Sincerely yours,
>
> Nodoka Yamanaka.
>
>
>