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

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.
Authors:
 [1] ;  [2]
  1. Department of Physics, McGill University, Rue University, Montréal, QC H3A 2T8 (Canada)
  2. Department of Physics and Astronomy, Louisiana State University, Tower Drive, Baton Rouge, 70803 (United States)
Publication Date:
OSTI Identifier:
22370626
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DUSTS; ENERGY DENSITY; GENERAL RELATIVITY THEORY; MATTER; PERTURBATION THEORY; QUANTUM COSMOLOGY; QUANTUM GRAVITY; SCALAR FIELDS; SCALARS; UNIVERSE