Name: Peter Blunden Date: 07/04/05-06:33:30 PM Z


The problem is that for some reason FourDivergence acting on DiracSlash gives 0.

In[2]:= fun=GS[p]//FCI
Out[2]= gs[p]

In[3]:= pa=FourVector[p,a];

In[4]:= FourDivergence[fun,pa]
Out[4]= 0

Here is a workaround:

In[5]:= fun2=DiracMatrix[b] FourVector[p,b]
Out[5]= ga[b] FourVector[p, b]

In[6]:= Contract[fun2]
Out[6]= gs[p]

In[7]:= FourDivergence[fun2,pa]
Out[7]= ga[a]

You can always use Contract afterward, if necessary.