-varying cosmological term: Emergence and fate of a FRW universe
Dec, 2003Citations per year
Abstract: (arXiv)
A time-varying cosmological "constant" Lambda is consistent with Einstein's equation, provided matter and/or radiation is created or destroyed to compensate for it. Supposing an empty primordial universe endowed with a very large cosmological term, matter will emerge gradually as Lambda decays. Provided only radiation or ultrarelativistic matter is initially created, the universe starts in a nearly de Sitter phase, which evolves towards a FRW regime as expansion proceeds. If, at some cosmological time, the cosmological term begins increasing again, as presently observed, expansion will accelerate and matter and/or radiation will be transformed back into dark energy. It is shown that such accelerated expansion is a route towards a new kind of gravitational singular state, characterized by an empty, conformally transitive spacetime in which all energy is dark.Note:
- RevTeX, 7 pages, no figures. Version 3: title and presentation changes; an appendix and references added. Version to be published in Gravitation & Cosmology
- cosmological constant
- fundamental constant: time dependence
- dark energy
- space-time: Robertson-Walker
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