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arXiv · 1402.3009

Non-singular bounce scenarios in loop quantum cosmology and the effective field description

Yi-Fu Cai·Edward Wilson-Ewing
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Abstract

A non-singular bouncing cosmology is generically obtained in loop quantum cosmology due to non-perturbative quantum gravity effects. A similar picture can be achieved in standard general relativity in the presence of a scalar field with a non-standard kinetic term such that at high energy densities the field evolves into a ghost condensate and causes a non-singular bounce. During the bouncing phase, the perturbations can be stabilized by introducing a Horndeski operator. Taking the matter content to be a dust field and an ekpyrotic scalar field, we compare the dynamics in loop quantum cosmology and in a non-singular bouncing effective field model with a non-standard kinetic term at both the background and perturbative levels. We find that these two settings share many important properties, including the result that they both generate scale-invariant scalar perturbations. This shows that some quantum gravity effects of the very early universe may be mimicked by effective field models.

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Yi-Fu Cai, Edward Wilson-Ewing. 2014-03-12. Non-singular bounce scenarios in loop quantum cosmology and the effective field description. https://doi.org/10.1088/1475-7516%2F2014%2F03%2F026

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