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Nonsingular power-law and assisted inflation in loop quantum cosmology

Evan Ranken1,* and Parampreet Singh2,†

  • 1Department of Physics, Colorado College, Colorado Springs, Colorado 80903, USA
  • 2Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA

  • *evan.ranken@coloradocollege.edu
  • †psingh@phys.lsu.edu
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Phys. Rev. D 85, 104002 – Published 3 May, 2012

DOI: https://doi.org/10.1103/PhysRevD.85.104002

Abstract

We investigate the dynamics of single and multiple scalar fields with exponential potentials, leading to power-law and assisted inflation, in loop quantum cosmology. Unlike in the classical theory, dynamical trajectories in loop quantum cosmology are generically nonsingular, with a big bounce replacing classical big bang in the Planck regime. Post-bounce, after a phase of superinflation, dynamical trajectories evolve towards the classical attractor in the inflationary scenarios. Depending on the initial conditions, bounce is shown to occur in kinetic as well as potential dominated regimes. We analyze the number of e-foldings resulting from the phase of superinflation and find the dependence of the maximum possible number of e-foldings on the equation of state at the bounce and on the steepness of the potential. We find that if the potential is not steep, this phase can lead to a large number of e-foldings in power-law inflation. For the assisted inflation scenario, an increase in the number of fields can yield a significant increase in the number of e-foldings during superinflation.

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Phys. Rev. D 85, 104002– Published 3 May, 2012
  • Received 20 March 2012
Article part of CHORUS

© 2012 American Physical Society

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