MULTIDIMENSIONAL COSMOLOGICAL WORLD MODELS AS 2-DIMENSIONAL DYNAMIC-SYSTEMS

We investigate the dynamics of two kinds of multidimensional cosmological models: (1) FRW (K=±1)×TD and (2) FRW (K=0)×SD, with the hydrodynamical energy-momentum tensor Tμv=diag(ρ{variant}, mρ{variant}, mρ{variant}, nρ{variant}, ..., nρ{variant}). It is shown that a full classification of these models on the two-dimensional phase-space is possible. Phase-portraits allow a simple discussion of various dynamical effects of extra dimensions. © 1990.