]> www.ginac.de Git - ginac.git/blobdiff - ginac/color.cpp
- inserted a couple of missing namepace std:: resolutions.
[ginac.git] / ginac / color.cpp
index e36c1cbe9796effef77d085d228bb4f5be614894..adcd8740f2ab7686a7babde2ca6a493cfa998394 100644 (file)
@@ -24,7 +24,6 @@
 #include <stdexcept>
 
 #include "color.h"
-#include "ex.h"
 #include "idx.h"
 #include "ncmul.h"
 #include "numeric.h"
@@ -145,7 +144,7 @@ DEFAULT_COMPARE(su3t)
 DEFAULT_COMPARE(su3f)
 DEFAULT_COMPARE(su3d)
 
-DEFAULT_PRINT(su3one, "ONE")
+DEFAULT_PRINT_LATEX(su3one, "ONE", "\\mathbb{1}")
 DEFAULT_PRINT(su3t, "T")
 DEFAULT_PRINT(su3f, "f")
 DEFAULT_PRINT(su3d, "d")
@@ -154,10 +153,10 @@ DEFAULT_PRINT(su3d, "d")
  *  objects. This removes superfluous ONEs. */
 ex color::simplify_ncmul(const exvector & v) const
 {
-       //!! TODO: sort by representation label
        exvector s;
        s.reserve(v.size());
 
+       // Remove superfluous ONEs
        exvector::const_iterator it = v.begin(), itend = v.end();
        while (it != itend) {
                if (!is_ex_of_type(it->op(0), su3one))
@@ -166,9 +165,7 @@ ex color::simplify_ncmul(const exvector & v) const
        }
 
        if (s.size() == 0)
-               return color(su3one());
-       else if (s.size() == v.size())
-               return simplified_ncmul(v);
+               return color(su3one(), representation_label);
        else
                return simplified_ncmul(s);
 }
@@ -297,6 +294,56 @@ ex su3f::eval_indexed(const basic & i) const
 }
 
 
+/** Contraction of generator with something else. */
+bool su3t::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
+{
+       GINAC_ASSERT(is_ex_of_type(*self, indexed));
+       GINAC_ASSERT(is_ex_of_type(*other, indexed));
+       GINAC_ASSERT(self->nops() == 2);
+       GINAC_ASSERT(is_ex_of_type(self->op(0), su3t));
+       unsigned char rl = ex_to_color(*self).get_representation_label();
+
+       if (is_ex_exactly_of_type(other->op(0), su3t)) {
+
+               // T.a T.a = 4/3 ONE
+               if (other - self == 1) {
+                       *self = numeric(4, 3);
+                       *other = color_ONE(rl);
+                       return true;
+
+               // T.a T.b T.a = -1/6 T.b
+               } else if (other - self == 2
+                       && is_ex_of_type(self[1], color)) {
+                       *self = numeric(-1, 6);
+                       *other = _ex1();
+                       return true;
+
+               // T.a S T.a = 1/2 Tr(S) - 1/6 S
+               } else {
+                       exvector::iterator it = self + 1;
+                       while (it != other) {
+                               if (!is_ex_of_type(*it, color)) {
+                                       return false;
+                               }
+                               it++;
+                       }
+
+                       it = self + 1;
+                       ex S = _ex1();
+                       while (it != other) {
+                               S *= *it;
+                               *it++ = _ex1();
+                       }
+
+                       *self = color_trace(S, rl) * color_ONE(rl) / 2 - S / 6;
+                       *other = _ex1();
+                       return true;
+               }
+       }
+
+       return false;
+}
+
 /** Contraction of an indexed symmetric structure constant with something else. */
 bool su3d::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
 {
@@ -308,25 +355,49 @@ bool su3d::contract_with(exvector::iterator self, exvector::iterator other, exve
        if (is_ex_exactly_of_type(other->op(0), su3d)) {
 
                // Find the dummy indices of the contraction
-               exvector dummy_indices;
-               dummy_indices = ex_to_indexed(*self).get_dummy_indices(ex_to_indexed(*other));
-
-               // d.abc*d.abc=40/3
+               exvector self_indices = ex_to_indexed(*self).get_indices();
+               exvector other_indices = ex_to_indexed(*other).get_indices();
+               exvector all_indices = self_indices;
+               all_indices.insert(all_indices.end(), other_indices.begin(), other_indices.end());
+               exvector free_indices, dummy_indices;
+               find_free_and_dummy(all_indices, free_indices, dummy_indices);
+
+               // d.abc d.abc = 40/3
                if (dummy_indices.size() == 3) {
                        *self = numeric(40, 3);
                        *other = _ex1();
                        return true;
 
-               // d.akl*d.bkl=5/3*delta.ab
+               // d.akl d.bkl = 5/3 delta.ab
                } else if (dummy_indices.size() == 2) {
-                       exvector a = index_set_difference(ex_to_indexed(*self).get_indices(), dummy_indices);
-                       exvector b = index_set_difference(ex_to_indexed(*other).get_indices(), dummy_indices);
-                       GINAC_ASSERT(a.size() > 0);
-                       GINAC_ASSERT(b.size() > 0);
-                       *self = numeric(5, 3) * delta_tensor(a[0], b[0]);
+                       exvector a;
+                       std::back_insert_iterator<exvector> ita(a);
+                       ita = set_difference(self_indices.begin(), self_indices.end(), dummy_indices.begin(), dummy_indices.end(), ita, ex_is_less());
+                       ita = set_difference(other_indices.begin(), other_indices.end(), dummy_indices.begin(), dummy_indices.end(), ita, ex_is_less());
+                       GINAC_ASSERT(a.size() == 2);
+                       *self = numeric(5, 3) * delta_tensor(a[0], a[1]);
                        *other = _ex1();
                        return true;
                }
+
+       } else if (is_ex_exactly_of_type(other->op(0), su3t)) {
+
+               // d.abc T.b T.c = 5/6 T.a
+               if (other+1 != v.end()
+                && is_ex_exactly_of_type(other[1].op(0), su3t)
+                && ex_to_indexed(*self).has_dummy_index_for(other[1].op(1))) {
+
+                       exvector self_indices = ex_to_indexed(*self).get_indices();
+                       exvector dummy_indices;
+                       dummy_indices.push_back(other[0].op(1));
+                       dummy_indices.push_back(other[1].op(1));
+                       int sig;
+                       ex a = permute_free_index_to_front(self_indices, dummy_indices, sig);
+                       *self = numeric(5, 6);
+                       other[0] = color_T(a, ex_to_color(other[0]).get_representation_label());
+                       other[1] = _ex1();
+                       return true;
+               }
        }
 
        return false;
@@ -346,13 +417,13 @@ bool su3f::contract_with(exvector::iterator self, exvector::iterator other, exve
                exvector dummy_indices;
                dummy_indices = ex_to_indexed(*self).get_dummy_indices(ex_to_indexed(*other));
 
-               // f.abc*f.abc=24
+               // f.abc f.abc = 24
                if (dummy_indices.size() == 3) {
                        *self = 24;
                        *other = _ex1();
                        return true;
 
-               // f.akl*f.bkl=3*delta.ab
+               // f.akl f.bkl = 3 delta.ab
                } else if (dummy_indices.size() == 2) {
                        int sign1, sign2;
                        ex a = permute_free_index_to_front(ex_to_indexed(*self).get_indices(), dummy_indices, sign1);
@@ -361,6 +432,25 @@ bool su3f::contract_with(exvector::iterator self, exvector::iterator other, exve
                        *other = _ex1();
                        return true;
                }
+
+       } else if (is_ex_exactly_of_type(other->op(0), su3t)) {
+
+               // f.abc T.b T.c = 3/2 I T.a
+               if (other+1 != v.end()
+                && is_ex_exactly_of_type(other[1].op(0), su3t)
+                && ex_to_indexed(*self).has_dummy_index_for(other[1].op(1))) {
+
+                       exvector self_indices = ex_to_indexed(*self).get_indices();
+                       exvector dummy_indices;
+                       dummy_indices.push_back(other[0].op(1));
+                       dummy_indices.push_back(other[1].op(1));
+                       int sig;
+                       ex a = permute_free_index_to_front(self_indices, dummy_indices, sig);
+                       *self = numeric(3, 2) * sig * I;
+                       other[0] = color_T(a, ex_to_color(other[0]).get_representation_label());
+                       other[1] = _ex1();
+                       return true;
+               }
        }
 
        return false;