Name: Sharaz (email_not_shown)
Date: 03/15/10-05:26:39 PM Z


Hi forum,

has anyone been able to introduce custom symmetries for TensorFunction? For instance if you want to define the Riemann tensor including contractions and symmetries.

On can easily define rules for contraction of Riemann tensor MT[m_,n_]TensorFunction[R,m_,a,n_,b]->TensorFunction[R,a,b]
MT[a_,b_]TensorFunction[R,a_,b_]->R

But can one tell feyncalc about the symmetries
TensorFunction[R,a,b,c,d]=-TensorFunction[R,b,a,c,d]=-TensorFunction[R,a,b,d,c]=TensorFunction[R,b,a,d,c]=TensorFunction[R,c,d,a,b]
and let it use the internal dummy index algorithm?



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