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http://arxiv.org/gr-qc/0406042 [Broken]

Oscillatory Universes in Loop Quantum Cosmology and Initial Conditions for Inflation

James E. Lidsey, David J. Mulryne, N. J. Nunes, Reza Tavakol

6 pages, 4 figures

LQC continues attracting new researchers: these people are newcomers in the field this year AFAIK. They are at the University of London. looks like a the start of a group there

"Our aim here is to study oscillatory universes within the context of Loop Quantum Cosmology (LQC) which is the application of Loop Quantum Gravity(LQG) to anhomogeneous minisuperspace environment. LQG is at presentthe main background independent and non– perturbative candidate for a quantum theory of gravity(see for example[4, 5]). This approach provides a (discrete) description of high–energy dynamics in the form of a difference equation. An important consequence of this discretization is the removal of the initial singularity [6]. As the universe expands and its volume increases, it enters an intermediate semi–classical phase in which the evolution equations take a continuous form but include modifications due to non–perturbative quantization effects [7]..."

Abstract:

"Positively-curved, oscillatory universes are studied within the context of Loop Quantum Cosmology subject to a consistent semi-classical treatment. The semi-classical effects are reformulated in terms of an effective phantom fluid with a variable equation of state. In cosmologies sourced by a massless scalar field, these effects lead to a universe that undergoes ever-repeating cycles of expansion and contraction. The presence of a self-interaction potential for the field breaks the symmetry of the cycles and can enable the oscillations to establish the initial conditions for successful slow-roll inflation, even when the field is initially at the minimum of its potential. The displacement of the field from its minimum is enhanced for lower and more natural values of the parameter that sets the effective quantum gravity scale. For sufficiently small values of this parameter, the universe can enter a stage of eternal self-reproduction."

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# Oscillatory Universes in Loop Quantum Cosmology

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