* Implementation of GiNaC's clifford algebra (Dirac gamma) objects. */
/*
- * GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include "symmetry.h"
#include "lst.h"
#include "relational.h"
+#include "operators.h"
#include "mul.h"
#include "print.h"
#include "archive.h"
GINAC_IMPLEMENT_REGISTERED_CLASS(diracone, tensor)
GINAC_IMPLEMENT_REGISTERED_CLASS(diracgamma, tensor)
GINAC_IMPLEMENT_REGISTERED_CLASS(diracgamma5, tensor)
-
GINAC_IMPLEMENT_REGISTERED_CLASS(diracgammaL, tensor)
GINAC_IMPLEMENT_REGISTERED_CLASS(diracgammaR, tensor)
+
//////////
-// default ctor, dtor, copy ctor, assignment operator and helpers
+// default constructors
//////////
clifford::clifford() : representation_label(0)
tinfo_key = TINFO_clifford;
}
-void clifford::copy(const clifford & other)
-{
- inherited::copy(other);
- representation_label = other.representation_label;
-}
-
-DEFAULT_DESTROY(clifford)
-DEFAULT_CTORS(diracone)
-DEFAULT_CTORS(diracgamma)
-DEFAULT_CTORS(diracgamma5)
+DEFAULT_CTOR(diracone)
+DEFAULT_CTOR(diracgamma)
+DEFAULT_CTOR(diracgamma5)
+DEFAULT_CTOR(diracgammaL)
+DEFAULT_CTOR(diracgammaR)
-DEFAULT_CTORS(diracgammaL)
-DEFAULT_CTORS(diracgammaR)
//////////
// other constructors
//////////
// archiving
//////////
-clifford::clifford(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
+clifford::clifford(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
{
unsigned rl;
n.find_unsigned("label", rl);
DEFAULT_ARCHIVING(diracone)
DEFAULT_ARCHIVING(diracgamma)
DEFAULT_ARCHIVING(diracgamma5)
-
DEFAULT_ARCHIVING(diracgammaL)
DEFAULT_ARCHIVING(diracgammaR)
+
//////////
// functions overriding virtual functions from base classes
//////////
GINAC_ASSERT(is_a<diracgamma>(self->op(0)));
unsigned char rl = ex_to<clifford>(*self).get_representation_label();
+ ex dim = ex_to<idx>(self->op(1)).get_dim();
+ if (other->nops() > 1)
+ dim = minimal_dim(dim, ex_to<idx>(other->op(1)).get_dim());
+
if (is_a<clifford>(*other)) {
// Contraction only makes sense if the represenation labels are equal
if (ex_to<clifford>(*other).get_representation_label() != rl)
return false;
- ex dim = ex_to<idx>(self->op(1)).get_dim();
-
// gamma~mu gamma.mu = dim ONE
if (other - self == 1) {
*self = dim;
*other = _ex1;
return true;
}
+
+ } else if (is_a<symbol>(other->op(0)) && other->nops() == 2) {
+
+ // x.mu gamma~mu -> x-slash
+ *self = dirac_slash(other->op(0), dim, rl);
+ *other = _ex1;
+ return true;
}
return false;
/** Perform automatic simplification on noncommutative product of clifford
* objects. This removes superfluous ONEs, permutes gamma5/L/R's to the front
* and removes squares of gamma objects. */
-ex clifford::simplify_ncmul(const exvector & v) const
+ex clifford::eval_ncmul(const exvector & v) const
{
exvector s;
s.reserve(v.size());
} else if (!a_is_diracgamma && !b_is_diracgamma && ag.is_equal(bg)) {
// a\ a\ -> a^2
- varidx ix((new symbol)->setflag(status_flags::dynallocated), ex_to<idx>(a.op(1)).get_dim());
+ varidx ix((new symbol)->setflag(status_flags::dynallocated), ex_to<idx>(a.op(1)).minimal_dim(ex_to<idx>(b.op(1))));
a = indexed(ag, ix) * indexed(ag, ix.toggle_variance());
b = dirac_ONE(representation_label);
something_changed = true;
if (s.empty())
return clifford(diracone(), representation_label) * sign;
if (something_changed)
- return nonsimplified_ncmul(s) * sign;
+ return reeval_ncmul(s) * sign;
else
- return simplified_ncmul(s) * sign;
+ return hold_ncmul(s) * sign;
}
-ex clifford::thisexprseq(const exvector & v) const
+ex clifford::thiscontainer(const exvector & v) const
{
return clifford(representation_label, v);
}
-ex clifford::thisexprseq(exvector * vp) const
+ex clifford::thiscontainer(exvector * vp) const
{
return clifford(representation_label, vp);
}
return clifford(diracgammaR(), rl);
}
-ex dirac_gamma6(unsigned char rl)
-{
- return clifford(diracone(), rl) + clifford(diracgamma5(), rl);
-}
-
-ex dirac_gamma7(unsigned char rl)
-{
- return clifford(diracone(), rl) - clifford(diracgamma5(), rl);
-}
-
ex dirac_slash(const ex & e, const ex & dim, unsigned char rl)
{
// Slashed vectors are actually stored as a clifford object with the
/** Take trace of a string of an even number of Dirac gammas given a vector
* of indices. */
-static ex trace_string(exvector::const_iterator ix, unsigned num)
+static ex trace_string(exvector::const_iterator ix, size_t num)
{
// Tr gamma.mu gamma.nu = 4 g.mu.nu
if (num == 2)
return lorentz_g(ix[0], ix[1]);
- // Tr gamma.mu gamma.nu gamma.rho gamma.sig = 4 (g.mu.nu g.rho.sig + g.nu.rho g.mu.sig - g.mu.rho g.nu.sig
+ // Tr gamma.mu gamma.nu gamma.rho gamma.sig = 4 (g.mu.nu g.rho.sig + g.nu.rho g.mu.sig - g.mu.rho g.nu.sig )
else if (num == 4)
return lorentz_g(ix[0], ix[1]) * lorentz_g(ix[2], ix[3])
+ lorentz_g(ix[1], ix[2]) * lorentz_g(ix[0], ix[3])
exvector v(num - 2);
int sign = 1;
ex result;
- for (unsigned i=1; i<num; i++) {
- for (unsigned n=1, j=0; n<num; n++) {
+ for (size_t i=1; i<num; i++) {
+ for (size_t n=1, j=0; n<num; n++) {
if (n == i)
continue;
v[j++] = ix[n];
else
return _ex0;
- } else if (is_ex_exactly_of_type(e, mul)) {
+ } else if (is_exactly_a<mul>(e)) {
// Trace of product: pull out non-clifford factors
ex prod = _ex1;
- for (unsigned i=0; i<e.nops(); i++) {
+ for (size_t i=0; i<e.nops(); i++) {
const ex &o = e.op(i);
if (is_clifford_tinfo(o.return_type_tinfo(), rl))
prod *= dirac_trace(o, rl, trONE);
}
return prod;
- } else if (is_ex_exactly_of_type(e, ncmul)) {
+ } else if (is_exactly_a<ncmul>(e)) {
if (!is_clifford_tinfo(e.return_type_tinfo(), rl))
return _ex0;
// gamma5 gets moved to the front so this check is enough
bool has_gamma5 = is_a<diracgamma5>(e.op(0).op(0));
- unsigned num = e.nops();
+ size_t num = e.nops();
if (has_gamma5) {
// I/4! * epsilon0123.mu1.mu2.mu3.mu4 * Tr gamma.mu1 gamma.mu2 gamma.mu3 gamma.mu4 S_2k
// (the epsilon is always 4-dimensional)
exvector ix(num-1), bv(num-1);
- for (unsigned i=1; i<num; i++)
+ for (size_t i=1; i<num; i++)
base_and_index(e.op(i), bv[i-1], ix[i-1]);
num--;
int *iv = new int[num];
ex result;
- for (unsigned i=0; i<num-3; i++) {
+ for (size_t i=0; i<num-3; i++) {
ex idx1 = ix[i];
- for (unsigned j=i+1; j<num-2; j++) {
+ for (size_t j=i+1; j<num-2; j++) {
ex idx2 = ix[j];
- for (unsigned k=j+1; k<num-1; k++) {
+ for (size_t k=j+1; k<num-1; k++) {
ex idx3 = ix[k];
- for (unsigned l=k+1; l<num; l++) {
+ for (size_t l=k+1; l<num; l++) {
ex idx4 = ix[l];
iv[0] = i; iv[1] = j; iv[2] = k; iv[3] = l;
exvector v;
v.reserve(num - 4);
- for (unsigned n=0, t=4; n<num; n++) {
+ for (size_t n=0, t=4; n<num; n++) {
if (n == i || n == j || n == k || n == l)
continue;
iv[t++] = n;
}
exvector iv(num), bv(num);
- for (unsigned i=0; i<num; i++)
+ for (size_t i=0; i<num; i++)
base_and_index(e.op(i), bv[i], iv[i]);
return trONE * (trace_string(iv.begin(), num) * mul(bv)).simplify_indexed();
// Scan for any ncmul objects
lst srl;
ex aux = e.to_rational(srl);
- for (unsigned i=0; i<srl.nops(); i++) {
+ for (size_t i=0; i<srl.nops(); i++) {
- ex lhs = srl.op(i).lhs();
- ex rhs = srl.op(i).rhs();
+ ex o = srl.op(i);
+ ex lhs = o.lhs();
+ ex rhs = o.rhs();
- if (is_ex_exactly_of_type(rhs, ncmul)
+ if (is_exactly_a<ncmul>(rhs)
&& rhs.return_type() == return_types::noncommutative
&& is_clifford_tinfo(rhs.return_type_tinfo())) {
// Expand product, if necessary
ex rhs_expanded = rhs.expand();
if (!is_a<ncmul>(rhs_expanded)) {
- srl.let_op(i) = (lhs == canonicalize_clifford(rhs_expanded));
+ srl[i] = (lhs == canonicalize_clifford(rhs_expanded));
continue;
} else if (!is_a<clifford>(rhs.op(0)))
exvector v;
v.reserve(rhs.nops());
- for (unsigned j=0; j<rhs.nops(); j++)
+ for (size_t j=0; j<rhs.nops(); j++)
v.push_back(rhs.op(j));
// Stupid recursive bubble sort because we only want to swap adjacent gammas
exvector::iterator it = v.begin(), next_to_last = v.end() - 1;
- if (is_a<diracgamma5>(it->op(0)))
+ if (is_a<diracgamma5>(it->op(0)) || is_a<diracgammaL>(it->op(0)) || is_a<diracgammaR>(it->op(0)))
++it;
while (it != next_to_last) {
if (it[0].compare(it[1]) > 0) {
it[0] = save1;
it[1] = save0;
sum -= ncmul(v, true);
- srl.let_op(i) = (lhs == canonicalize_clifford(sum));
+ srl[i] = (lhs == canonicalize_clifford(sum));
goto next_sym;
}
++it;