Primordial perturbations in a non singular bouncing universe model.

By P. Peter, N. Pinto-Neto. 2002

136 citations recorded by the source corpus.

We construct a simple non singular cosmological model in which the currently observed expansion phase was preceded by a contraction. This is achieved, in the framework of pure general relativity, by means of a radiation fluid and a free scalar field having negative energy. We calculate the power spectrum of the scalar perturbations that are produced in such a bouncing model and find that, under the assumption of initial vacuum state for the quantum field associated with the hydrodynamical perturbation, this leads to a spectral index n=-1. The matching conditions applying to this bouncing model are derived and shown to be different from those in the case of a sharp transition. We find that if our bounce transition can be smoothly connected to a slowly contracting phase, then the resulting power spectrum will be scale invariant.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/cb941a4abd08f71463d1e6cc59e3ed104184c638

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Citations in the corpus

Nonsingular cosmology with a scale-invariant spectrum of cosmological perturbations from Lee-Wick theory (2008, background): “[70] The use of a second scalar field to obtain a nonsingular bounce was already discussed in [7, 8] [71] In light of the trans-Planckian problem for inflationary fluctuations, one may view this prescription with some scepticism.”
Non-singular cosmology in a model of non-relativistic gravity (2009, methodology): “The scenario of bouncing cosmology has been investigated in models motivated by various approaches to quantum gravity [18–23], and analyzed using effective field techniques by introducing energy-condition-violating matters [11, 24–26], while the generation of perturbation was studied in [27–34] (and”
Bouncing Cosmologies: Progress and Problems (2016, background): “(60) It is now easy to see that even with a matter energymomentum tensor which obeys the NEC, it is possible to obtain a bounce if the gravitational contribution D̃µν(gαβ) is such that the effective energy-momentum tensor violates the NEC.”
The Matter Bounce Alternative to Inflationary Cosmology (2012, result): “[50] P.”