- added variants of dirac_trace() and color_trace() that take the trace over

[ginac.git] / ginac / clifford.h

diff --git a/ginac/clifford.h b/ginac/clifford.h
index f6a9820b6e9f08bfa5a1d6b21abf096d6f5da258..81abd9f5c879c956da862f009fc5f24f6b7bcbc4 100644 (file)
--- a/ginac/clifford.h
+++ b/ginac/clifford.h
@@ -28,6 +28,8 @@
 #include "symbol.h"
 #include "idx.h"
 
+#include <set>
+
 namespace GiNaC {
 
 
@@ -35,7 +37,7 @@ namespace GiNaC {
  *  algebra (the Dirac gamma matrices). These objects only carry Lorentz
  *  indices. Spinor indices are hidden. A representation label (an unsigned
  *  8-bit integer) is used to distinguish elements from different Clifford
- *  algebras (objects with different labels commute). */
+ *  algebras (objects with different labels commutate). */
 class clifford : public indexed
 {
        GINAC_DECLARE_REGISTERED_CLASS(clifford, indexed)
@@ -124,7 +126,7 @@ protected:
 };
 
 
-/** This class represents the Dirac gamma5 object which anticommutes with
+/** This class represents the Dirac gamma5 object which anticommutates with
  *  all other gammas. */
 class diracgamma5 : public tensor
 {
@@ -226,6 +228,26 @@ ex dirac_gammaR(unsigned char rl = 0);
  *  @param rl Representation label */
 ex dirac_slash(const ex & e, const ex & dim, unsigned char rl = 0);
 
+/** Calculate dirac traces over the specified set of representation labels.
+ *  The computed trace is a linear functional that is equal to the usual
+ *  trace only in D = 4 dimensions. In particular, the functional is not
+ *  always cyclic in D != 4 dimensions when gamma5 is involved.
+ *
+ *  @param e Expression to take the trace of
+ *  @param rls Set of representation labels
+ *  @param trONE Expression to be returned as the trace of the unit matrix */
+ex dirac_trace(const ex & e, const std::set<unsigned char> & rls, const ex & trONE = 4);
+
+/** Calculate dirac traces over the specified list of representation labels.
+ *  The computed trace is a linear functional that is equal to the usual
+ *  trace only in D = 4 dimensions. In particular, the functional is not
+ *  always cyclic in D != 4 dimensions when gamma5 is involved.
+ *
+ *  @param e Expression to take the trace of
+ *  @param rll List of representation labels
+ *  @param trONE Expression to be returned as the trace of the unit matrix */
+ex dirac_trace(const ex & e, const lst & rll, const ex & trONE = 4);
+
 /** 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.