Maple Professionel
Maple Académique
Maple Edition Étudiant
Maple Personal Edition
Maple Player
Maple Player for iPad
MapleSim Professionel
MapleSim Académique
Maple T.A. - Suite d'examens de classement
Maple T.A. MAA Placement Test Suite
Möbius - Didacticiels de mathématiques en ligne
Machine Design / Industrial Automation
Aéronautique
Ingénierie des véhicules
Robotics
Energie
System Simulation and Analysis
Model development for HIL
Modélisation du procédé pour la conception de systèmes de contrôle
Robotics/Motion Control/Mechatronics
Other Application Areas
Enseignement des mathématiques
Enseignement de l’ingénierie
Enseignement secondaire et supérieur (CPGE, BTS)
Tests et évaluations
Etudiants
Modélisation financière
Recherche opérationnelle
Calcul haute performance
Physique
Webinaires en direct
Webinaires enregistrés
Agenda des évènements
Forum MaplePrimes
Blog Maplesoft
Membres Maplesoft
Maple Ambassador Program
MapleCloud
Livres blancs techniques
Bulletin électronique
Livres Maple
Math Matters
Portail des applications
Galerie de modèles MapleSim
Cas d'Etudes Utilisateur
Exploring Engineering Fundamentals
Concepts d’enseignement avec Maple
Centre d’accueil utilisateur Maplesoft
Centre de ressources pour enseignants
Centre d’assistance aux étudiants
Tensor[EinsteinTensor] - calculate the Einstein tensor for a metric
Calling Sequences
EinsteinTensor(g, R)
Parameters
g - a metric tensor
R - (optional) the curvature tensor of the metric g
Description
Let Ric(g) and S(g) be the Ricci tensor and Ricci scalar for the metric g. Then the covariant form of the Einstein tensor is Ein(g) = Ric(g) - 1/2*g*S(g). The contravariant form is obtained by raising both indices of the covariant Einstein tensor with the metric g.
The program EinsteinTensor(g, R) returns the contravariant form of the Einstein tensor. This tensor is symmetric and its covariant divergence vanishes.
This command is part of the DifferentialGeometry:-Tensor package, and so can be used in the form EinsteinTensor(...) only after executing the command with(DifferentialGeometry) and with(Tensor) in that order. It can always be used in the long form DifferentialGeometry:-Tensor:-EinsteinTensor.
Examples
Example 1.
Create a 4 dimensional manifold M, define a metric g1, and calculate the Einstein tensor E1.
Calculate the Christoffel symbols for the metric g1.
Calculate the Einstein tensor for the metric g1.
Check that the covariant divergence of the Einstein tensor E1 vanishes.
See Also
Physics[Einstein], DifferentialGeometry, Tensor, Christoffel, Physics[Christoffel], ContractIndices, CovariantDerivative, Physics[D_], CurvatureTensor, Physics[Riemann], SectionalCurvature, RicciScalar, RicciTensor, Physics[Ricci]
Download Help Document