Non-singular Power-law and Assisted inflation in Loop Quantum Cosmology

TL;DR

This paper explores how loop quantum cosmology modifies inflationary dynamics, replacing the classical big bang with a bounce, and shows that multiple scalar fields can enhance inflationary e-foldings.

Contribution

It demonstrates the non-singular bounce in loop quantum cosmology and analyzes how initial conditions and multiple fields influence inflationary e-foldings.

Findings

Loop quantum cosmology replaces the big bang with a bounce.

Super-inflation phase can produce significant e-foldings.

Multiple fields increase e-foldings during super-inflation.

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 non-singular, with a big bounce replacing classical big bang in the Planck regime. Post bounce, after a phase of super-inflation, 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 super-inflation, 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 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 super-inflation.