9.7. Symmetric Trace-Free part

The command STFPart returns the symmetric, trace-free part of an expression with only free indices. In order for a symmetric object to have a trace we need to use a metric.

This is the STF part of a 3-index tensor without symmetry, and with respect to the metricg:

In[963]:=

Out[963]=

The result is not simplified at all. We must ask for explicit metric contraction and simplification:

In[964]:=

Out[964]=

Created by Mathematica  (May 16, 2008)