Loop Quantum Cosmology and the Fine Structure Constant

TL;DR

This paper explores how variations in the fine structure constant  within Loop Quantum Cosmology affect cosmic evolution, revealing bounce phenomena influenced by ghost scalar fields and loop quantum effects.

Contribution

It introduces a model combining varying  with Loop Quantum Cosmology, analyzing the dynamics with ghost scalar fields and matter coupling in flat and closed universes.

Findings

Series of cosmological bounces induced by ghost fields and loop effects

Variation of  impacts cosmic evolution in quantum gravity context

Dynamics depend on matter coupling and cosmological geometry

Abstract

The cosmological implications of introducing a variation to the fine structure `constant', \alpha are examined within the context of Loop Quantum Cosmology. The evolution of \alpha is described using the model introduced by Bekenstein, Sandvik, Barrow and Magueijo, in which a ghost scalar field produces the variation. The dynamics of the system are examined in flat and closed cosmological settings. Matter consisting of the scalar field and radiation are examined with a thermodynamically motivated coupling between the two, which can lead to a series of bounces induced by both the negative density effects of the ghost field and the loop effects.