COT4 - Nonsingular Cosmology - Inflation |
Speaker_ |
Dymnikova, Irina |
Talk _ |
Nonsingular vacuum cosmologies with the de Sitter origin |
Abstract _ |
The variable cosmological term $\Lambda^{\mu\nu}=8\pi G T^{\mu\nu}_{vac}$ is introduced by reducing symmetry of a vacuum stress-energy tensor in the frame of possibilities given by the Petrov classification. A cosmological vacuum with variable density and anisotropic pressure evolves between $(8\pi G )^{-1}\Lambda g_{\mu\nu}$ and $(8\pi G)^{-1}\lambda g_{\mu\nu}$, and generates regular spherically symmetric space-times with the de Sitter origin. In the regular cosmologies of the Lemaitr\'e class, inflation appears as an initial state, a non-singular non simultaneous de Sitter bang followed by a Kasner-type anisotropic stage. For regular cosmologies of Kantowski-Sachs type, this occurs in the regular ${\cal R}-$regions in their past; for Kantowski-Sachs observers evolution starts with a null bang from a horizon. |