calculates the Dirac trace of exp. Depending on the setting of the option SUNTrace also a trace over SU(N) objects is performed. The Mathematica build-in function Tr is overloaded to call TR if any of DiracGamma, DiracSlash, GA, GAD, GS or GSD are in the expression.
Tr[list] finds the trace of the matrix or tensor list. Tr[list, f] finds a generalized trace, combining terms with f instead of Plus. Tr[list, f, n] goes down to level n in list.
Tr[ expression ] calculates the DiracTrace, i.e., TR[ expression ] if any of DiracGamma, DiracSlash, GA, GAD, GS or GSD is present in expression.