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From de Sitter to de Sitter: A non-singular inflationary universe driven by vacuum

Saulo Carneiro
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Abstract

A semi-classical analysis of vacuum energy in the expanding spacetime suggests that the cosmological term decays with time, with a concomitant matter production. For early times we find, in Planck units, $Λ\approx H^4$, where H is the Hubble parameter. The corresponding cosmological solution has no initial singularity, existing since an infinite past. During an infinitely long period we have a quasi-de Sitter, inflationary universe, with $H \approx 1$. However, at a given time, the expansion undertakes a phase transition, with H and $Λ$ decreasing to nearly zero in a few Planck times, producing a huge amount of radiation. On the other hand, the late-time scenario is similar to the standard model, with the radiation phase followed by a dust era, which tends asymptotically to a de Sitter universe, with vacuum dominating again.

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Saulo Carneiro. 2006-05-26. From de Sitter to de Sitter: A non-singular inflationary universe driven by vacuum. https://doi.org/10.1142/s0218271806009510

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