Tachyon field in Loop Quantum Cosmology: inflation and evolution picture

TL;DR

This paper investigates how tachyon matter within loop quantum cosmology leads to a nonsingular universe evolution, featuring super inflation and a bounce, with numerical simulations illustrating the dynamics and comparison to classical inflation.

Contribution

It demonstrates that tachyon matter in LQC always results in a nonsingular bounce and extends classical inflation, including super inflation phases, with detailed numerical evolution analysis.

Findings

Quantum solutions exhibit attractor behavior similar to classical solutions.

The universe undergoes a bounce with tachyon field climbing and descending the potential.

Quantum inflation can be extended beyond classical limits.

Abstract

Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe through a bounce in the high energy region. We show that this is always true in tachyon matter LQC. Different from the classical Friedman-Robertson-Walker (FRW) cosmology, the super inflation can appear in the tachyon matter LQC; furthermore, the inflation can be extended to the region where classical inflation stops. Using numerical method, we give an evolution picture of the tachyon field with an exponential potential in the context of LQC. It indicates that the quantum dynamical solutions have the attractive behavior as the classical solutions do. The whole evolution of the tachyon field is that in the distant past, the tachyon field--being in the contracting cosmology--is accelerates to climb up the potential hill with a negative velocity; then at the boundary the tachyon field is bounced into an expanding universe with positive velocity rolling down to the bottom of the potential. In the slow roll limit, we compare the quantum inflation with the classical case in both an analytic and numerical way.