Onset of inflation in inhomogeneous cosmology

TL;DR

This paper investigates how initial inhomogeneities influence the start of inflation in a closed universe, using a scalar field model and gradient expansion to determine conditions for inflation onset.

Contribution

It introduces a method to analyze the impact of inhomogeneities on inflation onset in closed universes using the long wavelength approximation.

Findings

Identifies conditions under which inhomogeneities allow inflation to begin.

Demonstrates the applicability of the gradient expansion method in this context.

Provides criteria for the transition to inflation based on initial inhomogeneity levels.

Abstract

We study how the initial inhomogeneities of the universe affect the onset of inflation in the closed universe. We consider the model of a chaotic inflation which is driven by a massive scalar field. In order to construct an inhomogeneous universe model, we use the long wavelength approximation ( the gradient expansion method ). We show the condition of the inhomogeneities for the universe to enter the inflationary phase.