Inflation in Oscillating Universe

TL;DR

This paper investigates how high-energy corrections to the Friedmann equation enable a bouncing universe, leading to a novel inflationary scenario driven by scalar fields during contraction and post-bounce expansion.

Contribution

It introduces a semi-analytical and numerical study of inflation in an oscillating universe with a bounce, highlighting the role of kinetic contraction and energy scale constraints.

Findings

Kinetic contraction can precede inflation in bouncing models.

Scalar field dynamics are influenced by anti-friction during contraction.

Bounce energy scale constrains the inflationary e-folds.

Abstract

We make use of possible high energy correction to the Friedmann equation to implement the bounce and study the behavior of massive scalar field before and after bounce semianalytically and numerically. We find that the slow-roll inflation can be preceded by the kinetic dominated contraction. During this process, the field initially in the bottom of its potential can be driven by the anti-frictional force resulted from the contraction and roll up its potential hill, and when it rolls down after the bounce, it can driven a period inflation. The required e-folds number during the inflation limits the energy scale of bounce. Further unlike that expected, the field during the contraction can not be driven to arbitrary large value, even though the bounce occurs at Planck scale.