dirac_trace() can handle arbitrary gamma strings without gamma5. The only

[ginac.git] / ginac / clifford.h

diff --git a/ginac/clifford.h b/ginac/clifford.h
index 8ac696528873244d1ee6463e933425f256353973..f1783396995620d63c1a38f24315675f97476742 100644 (file)
--- a/ginac/clifford.h
+++ b/ginac/clifford.h
@@ -55,6 +55,10 @@ protected:
        unsigned return_type(void) const { return return_types::noncommutative; }
        unsigned return_type_tinfo(void) const { return TINFO_clifford + representation_label; }
 
+       // non-virtual functions in this class
+public:
+       unsigned char get_representation_label(void) const {return representation_label;}
+
        // member variables
 private:
        unsigned char representation_label; /**< Representation label to distinguish independent spin lines */
@@ -121,6 +125,15 @@ ex dirac_gamma(const ex & mu, unsigned char rl = 0);
  *  @return newly constructed object */
 ex dirac_gamma5(unsigned char rl = 0);
 
+/** Calculate the trace of an expression containing gamma objects with
+ *  a specified representation label. The computed trace is a linear
+ *  functional that is equal to the usual trace only in D = 4 dimensions.
+ *  In particular, the functional is non-cyclic in D != 4 dimensions when
+ *  gamma5 is involved.
+ *
+ *  @param rl Representation label */
+ex dirac_trace(const ex & e, unsigned char rl = 0);
+
 
 } // namespace GiNaC