Non-Minimally Coupled Inflation with Initial Conditions from a Pre-Inflation Anamorphic Contracting Era

TL;DR

This paper proposes a cosmological model where a universe transitions smoothly from an initial contracting phase to a non-minimally coupled inflationary phase, providing initial conditions and predicting observable spectral index corrections.

Contribution

It introduces a model connecting an anamorphic contracting era to non-minimally coupled inflation without a bounce, offering new initial conditions and observable predictions.

Findings

Smooth transition from contraction to inflation without bounce

Initial conditions from contraction support inflation

Predicted spectral index corrections increase observational compatibility

Abstract

Inflation due to a non-minimally coupled scalar field with a large non-minimal coupling, as first proposed by Salopek, Bardeen and Bond (SBB), is in good agreement with the observed value of the spectral index and constraints on the tensor-to-scalar ratio. Here we explore the possibility that SBB inflation represents the late stage of a Universe which emerges from an early contracting era. We present a model in which the Universe smoothly transitions from an anamorphic contracting era to late-time SBB inflation without encountering a singular bounce. This corresponds to a continuous expansion in the Einstein frame throughout. We show that the anamorphic contracting era is able to provide the smooth superhorizon initial conditions necessary for subsequent SBB inflation to occur. The model predicts corrections to the non-minimal coupling, kinetic term and potential of SBB inflation which can observably increase the observed spectral index relative to its SBB prediction.