GiNaC 1.8.7
tensor.h
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5/*
6 * GiNaC Copyright (C) 1999-2023 Johannes Gutenberg University Mainz, Germany
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22
23#ifndef GINAC_TENSOR_H
24#define GINAC_TENSOR_H
25
26#include "ex.h"
27#include "archive.h"
28
29namespace GiNaC {
30
34class tensor : public basic
35{
37
38 // functions overriding virtual functions from base classes
39protected:
40 unsigned return_type() const override { return return_types::noncommutative_composite; }
41
42 // non-virtual functions in this class
43public:
47 bool replace_contr_index(exvector::iterator self, exvector::iterator other) const;
48};
49
50
53class tensdelta : public tensor
54{
56
57 // functions overriding virtual functions from base classes
58public:
59 bool info(unsigned inf) const override;
60 ex eval_indexed(const basic & i) const override;
61 bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const override;
62protected:
63 unsigned return_type() const override { return return_types::commutative; }
64
65 // non-virtual functions in this class
66protected:
67 void do_print(const print_context & c, unsigned level) const;
68 void do_print_latex(const print_latex & c, unsigned level) const;
69};
71
72
76class tensmetric : public tensor
77{
79
80 // functions overriding virtual functions from base classes
81public:
82 bool info(unsigned inf) const override;
83 ex eval_indexed(const basic & i) const override;
84 bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const override;
85protected:
86 unsigned return_type() const override { return return_types::commutative; }
87
88 // non-virtual functions in this class
89protected:
90 void do_print(const print_context & c, unsigned level) const;
91};
93
94
98class minkmetric : public tensmetric
99{
101
102 // other constructors
103public:
105 minkmetric(bool pos_sig);
106
107 // functions overriding virtual functions from base classes
108public:
109 bool info(unsigned inf) const override;
110 ex eval_indexed(const basic & i) const override;
111
113 void archive(archive_node& n) const override;
115 void read_archive(const archive_node& n, lst& syms) override;
116protected:
117 unsigned return_type() const override { return return_types::commutative; }
118
119 // non-virtual functions in this class
120protected:
121 void do_print(const print_context & c, unsigned level) const;
122 void do_print_latex(const print_latex & c, unsigned level) const;
123
124 // member variables
125private:
126 bool pos_sig;
127};
129
130
135class spinmetric : public tensmetric
136{
138
139 // functions overriding virtual functions from base classes
140public:
141 bool info(unsigned inf) const override;
142 ex eval_indexed(const basic & i) const override;
143 bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const override;
144
145protected:
146 void do_print(const print_context & c, unsigned level) const;
147 void do_print_latex(const print_latex & c, unsigned level) const;
148};
150
151
155class tensepsilon : public tensor
156{
158
159 // other constructors
160public:
161 tensepsilon(bool minkowski, bool pos_sig);
162
163 // functions overriding virtual functions from base classes
164public:
165 bool info(unsigned inf) const override;
166 ex eval_indexed(const basic & i) const override;
167 bool contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const override;
168
170 void archive(archive_node& n) const override;
172 void read_archive(const archive_node& n, lst& syms) override;
173protected:
174 unsigned return_type() const override { return return_types::commutative; }
175
176 // non-virtual functions in this class
177protected:
178 void do_print(const print_context & c, unsigned level) const;
179 void do_print_latex(const print_latex & c, unsigned level) const;
180
181 // member variables
182private:
184 bool pos_sig;
185};
187
188
189// utility functions
190
198ex delta_tensor(const ex & i1, const ex & i2);
199
207ex metric_tensor(const ex & i1, const ex & i2);
208
218ex lorentz_g(const ex & i1, const ex & i2, bool pos_sig = false);
219
228ex spinor_metric(const ex & i1, const ex & i2);
229
236ex epsilon_tensor(const ex & i1, const ex & i2);
237
245ex epsilon_tensor(const ex & i1, const ex & i2, const ex & i3);
246
256ex lorentz_eps(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool pos_sig = false);
257
258} // namespace GiNaC
259
260#endif // ndef GINAC_TENSOR_H
Archiving of GiNaC expressions.
This class stores all properties needed to record/retrieve the state of one object of class basic (or...
Definition: archive.h:49
This class is the ABC (abstract base class) of GiNaC's class hierarchy.
Definition: basic.h:105
Wrapper template for making GiNaC classes out of STL containers.
Definition: container.h:73
Lightweight wrapper for GiNaC's symbolic objects.
Definition: ex.h:72
This class represents a Minkowski metric tensor.
Definition: tensor.h:99
minkmetric(bool pos_sig)
Construct Lorentz metric tensor with given signature.
Definition: tensor.cpp:75
ex eval_indexed(const basic &i) const override
Automatic symbolic evaluation of an indexed Lorentz metric tensor.
Definition: tensor.cpp:284
void do_print(const print_context &c, unsigned level) const
bool pos_sig
If true, the metric is diag(-1,1,1...).
Definition: tensor.h:126
void archive(archive_node &n) const override
Save (a.k.a.
Definition: tensor.cpp:106
void read_archive(const archive_node &n, lst &syms) override
Read (a.k.a.
Definition: tensor.cpp:99
bool info(unsigned inf) const override
Information about the object.
Definition: tensor.cpp:167
void do_print_latex(const print_latex &c, unsigned level) const
unsigned return_type() const override
Definition: tensor.h:117
Base class for print_contexts.
Definition: print.h:103
Context for latex-parsable output.
Definition: print.h:123
@ noncommutative_composite
Definition: flags.h:282
This class represents an antisymmetric spinor metric tensor which can be used to raise/lower indices ...
Definition: tensor.h:136
bool info(unsigned inf) const override
Information about the object.
Definition: tensor.cpp:196
ex eval_indexed(const basic &i) const override
Automatic symbolic evaluation of an indexed metric tensor.
Definition: tensor.cpp:311
void do_print_latex(const print_latex &c, unsigned level) const
void do_print(const print_context &c, unsigned level) const
bool contract_with(exvector::iterator self, exvector::iterator other, exvector &v) const override
Contraction of an indexed spinor metric with something else.
Definition: tensor.cpp:462
This class represents the delta tensor.
Definition: tensor.h:54
bool contract_with(exvector::iterator self, exvector::iterator other, exvector &v) const override
Contraction of an indexed delta tensor with something else.
Definition: tensor.cpp:431
unsigned return_type() const override
Definition: tensor.h:63
void do_print_latex(const print_latex &c, unsigned level) const
void do_print(const print_context &c, unsigned level) const
bool info(unsigned inf) const override
Information about the object.
Definition: tensor.cpp:140
ex eval_indexed(const basic &i) const override
Automatic symbolic evaluation of an indexed delta tensor.
Definition: tensor.cpp:211
This class represents the totally antisymmetric epsilon tensor.
Definition: tensor.h:156
void do_print_latex(const print_latex &c, unsigned level) const
bool minkowski
If true, tensor is in Minkowski-type space.
Definition: tensor.h:183
bool pos_sig
If true, the metric is assumed to be diag(-1,1,1...).
Definition: tensor.h:184
void read_archive(const archive_node &n, lst &syms) override
Read (a.k.a.
Definition: tensor.cpp:112
unsigned return_type() const override
Definition: tensor.h:174
bool contract_with(exvector::iterator self, exvector::iterator other, exvector &v) const override
Contraction of epsilon tensor with something else.
Definition: tensor.cpp:542
bool info(unsigned inf) const override
Information about the object.
Definition: tensor.cpp:188
void do_print(const print_context &c, unsigned level) const
tensepsilon(bool minkowski, bool pos_sig)
Definition: tensor.cpp:87
void archive(archive_node &n) const override
Save (a.k.a.
Definition: tensor.cpp:120
ex eval_indexed(const basic &i) const override
Automatic symbolic evaluation of an indexed epsilon tensor.
Definition: tensor.cpp:342
This class represents a general metric tensor which can be used to raise/lower indices.
Definition: tensor.h:77
bool info(unsigned inf) const override
Information about the object.
Definition: tensor.cpp:148
unsigned return_type() const override
Definition: tensor.h:86
void do_print(const print_context &c, unsigned level) const
ex eval_indexed(const basic &i) const override
Automatic symbolic evaluation of an indexed metric tensor.
Definition: tensor.cpp:253
bool contract_with(exvector::iterator self, exvector::iterator other, exvector &v) const override
Contraction of an indexed metric tensor with something else.
Definition: tensor.cpp:444
This class holds one of GiNaC's predefined special tensors such as the delta and the metric tensors.
Definition: tensor.h:35
unsigned return_type() const override
Definition: tensor.h:40
bool replace_contr_index(exvector::iterator self, exvector::iterator other) const
Replace dummy index in contracted-with object by the contracting object's second index (used internal...
Definition: tensor.cpp:388
Interface to GiNaC's light-weight expression handles.
size_t n
Definition: factor.cpp:1432
size_t c
Definition: factor.cpp:757
exset syms
Definition: factor.cpp:2429
Definition: add.cpp:38
ex spinor_metric(const ex &i1, const ex &i2)
Create a spinor metric tensor with specified indices.
Definition: tensor.cpp:608
ex metric_tensor(const ex &i1, const ex &i2)
Create a symmetric metric tensor with specified indices.
Definition: tensor.cpp:587
GINAC_DECLARE_UNARCHIVER(add)
ex delta_tensor(const ex &i1, const ex &i2)
Create a delta tensor with specified indices.
Definition: tensor.cpp:577
ex lorentz_eps(const ex &i1, const ex &i2, const ex &i3, const ex &i4, bool pos_sig)
Create an epsilon tensor in a Minkowski space with four indices.
Definition: tensor.cpp:658
ex lorentz_g(const ex &i1, const ex &i2, bool pos_sig)
Create a Minkowski metric tensor with specified indices.
Definition: tensor.cpp:597
std::vector< ex > exvector
Definition: basic.h:48
ex epsilon_tensor(const ex &i1, const ex &i2)
Create an epsilon tensor in a Euclidean space with two indices.
Definition: tensor.cpp:620
#define GINAC_DECLARE_REGISTERED_CLASS(classname, supername)
Macro for inclusion in the declaration of each registered class.
Definition: registrar.h:153

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