/** @file clifford.h
*
- * Interface to GiNaC's clifford objects. */
+ * Interface to GiNaC's clifford algebra (Dirac gamma) objects. */
/*
* GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
#ifndef __GINAC_CLIFFORD_H__
#define __GINAC_CLIFFORD_H__
-#include <string>
-#include "lortensor.h"
+#include "indexed.h"
+#include "tensor.h"
-#ifndef NO_NAMESPACE_GINAC
namespace GiNaC {
-#endif // ndef NO_NAMESPACE_GINAC
/** This class holds an object representing an element of the Clifford
* algebra (the Dirac gamma matrices). These objects only carry Lorentz
- * indices. Spinor indices are always hidden in our implementation. */
-class clifford : public lortensor
+ * 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). */
+class clifford : public indexed
{
- GINAC_DECLARE_REGISTERED_CLASS(clifford, lortensor)
-
-// friends
-
- friend clifford clifford_gamma(const ex & mu);
+ GINAC_DECLARE_REGISTERED_CLASS(clifford, indexed)
// other constructors
public:
- clifford(const std::string & n, const ex & mu);
- clifford(const std::string & n, const exvector & iv);
- clifford(const std::string & n, exvector * ivp);
+ clifford(const ex & b, unsigned char rl = 0);
+ clifford(const ex & b, const ex & mu, unsigned char rl = 0);
+
+ // internal constructors
+ clifford(unsigned char rl, const exvector & v, bool discardable = false);
+ clifford(unsigned char rl, exvector * vp); // vp will be deleted
// functions overriding virtual functions from base classes
-public:
- basic * duplicate() const;
- void printraw(std::ostream & os) const;
- void printtree(std::ostream & os, unsigned indent) const;
- void print(std::ostream & os, unsigned upper_precedence=0) const;
- bool info(unsigned inf) const;
- // ex eval(int level=0) const;
protected:
- int compare_same_type(const basic & other) const;
- bool is_equal_same_type(const basic & other) const;
ex simplify_ncmul(const exvector & v) const;
ex thisexprseq(const exvector & v) const;
ex thisexprseq(exvector * vp) const;
-
- // new virtual functions which can be overridden by derived classes
- // none
-
- // non-virtual functions in this class
- // none
+ unsigned return_type(void) const { return return_types::noncommutative; }
+ unsigned return_type_tinfo(void) const { return TINFO_clifford + representation_label; }
// member variables
- // none
+private:
+ unsigned char representation_label; /**< Representation label to distinguish independent spin lines */
+};
+
+
+/** This class represents the Clifford algebra unity element. */
+class diracone : public tensor
+{
+ GINAC_DECLARE_REGISTERED_CLASS(diracone, tensor)
+
+ // functions overriding virtual functions from bases classes
+public:
+ void print(const print_context & c, unsigned level = 0) const;
};
+
+/** This class represents the Dirac gamma Lorentz vector. */
+class diracgamma : public tensor
+{
+ GINAC_DECLARE_REGISTERED_CLASS(diracgamma, tensor)
+
+ // functions overriding virtual functions from bases classes
+public:
+ void print(const print_context & c, unsigned level = 0) const;
+ bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const;
+};
+
+
+/** This class represents the Dirac gamma5 object. */
+class diracgamma5 : public tensor
+{
+ GINAC_DECLARE_REGISTERED_CLASS(diracgamma5, tensor)
+
+ // functions overriding virtual functions from bases classes
+public:
+ void print(const print_context & c, unsigned level = 0) const;
+};
+
+
// global functions
inline const clifford &ex_to_clifford(const ex &e)
{
return static_cast<const clifford &>(*e.bp);
}
-clifford clifford_gamma(const ex & mu);
-#ifndef NO_NAMESPACE_GINAC
+/** Create a Clifford unity object.
+ *
+ * @param rl Representation label
+ * @return newly constructed object */
+ex dirac_ONE(unsigned char rl = 0);
+
+/** Create a Dirac gamma object.
+ *
+ * @param mu Index (must be of class varidx or a derived class)
+ * @param rl Representation label
+ * @return newly constructed gamma object */
+ex dirac_gamma(const ex & mu, unsigned char rl = 0);
+
+/** Create a Dirac gamma5 object.
+ *
+ * @param rl Representation label
+ * @return newly constructed object */
+ex dirac_gamma5(unsigned char rl = 0);
+
+
} // namespace GiNaC
-#endif // ndef NO_NAMESPACE_GINAC
#endif // ndef __GINAC_CLIFFORD_H__