General Relativity and Gravitation

, Volume 20, Issue 11, pp 1127–1139 | Cite as

Using EXCALC to study nondiagonal multidimensional spatially homogeneous cosmologies

  • Y. De Rop
  • J. Demaret
Research Articles


The exterior calculus package EXCALC2, developed by Schrüfer, is used to implement Siklos' method on a computer. By an appropriate choice of the 1-form basis of spatially homogeneous cosmological models, making use of the time-dependent automorphisms of the Lie algebra, it is possible to obtain a compact form of Einstein's field equations for general models of this type. The explicit expression of the equations, obtained with the help of EXCALC2, is given here for two nondiagonal five-dimensional spatially homogeneous models, namely G1 and G8. These equations constitute an ideal tool for the study of the dynamics of these models: an oscillatory behavior has been found for model G1, while model G8 exhibits a monotonous kasnerian mode of approach to the initial singularity.


General Model Explicit Expression Field Equation Differential Geometry Cosmological Model 
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Copyright information

© Plenum Publishing Corporation 1988

Authors and Affiliations

  • Y. De Rop
    • 1
  • J. Demaret
    • 2
  1. 1.Département de PhysiqueFacultés universitaires Notre-Dame de la PaixNamurBelgium
  2. 2.Institut d'AstrophysiqueUniversité de LiègeCointe-OugréeBelgium

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