Phantom Inflation in Little Rip

TL;DR

This paper explores phantom inflation within little rip cosmology, showing that a universe with a w < -1 parameter can undergo inflation before a rip singularity at infinite time, with perturbation spectra consistent with observations.

Contribution

It introduces a model of phantom inflation in little rip cosmology and numerically analyzes primordial perturbations, linking current acceleration to potential future inflation.

Findings

Primordial perturbation spectrum aligns with observational data.

Universe can undergo inflation before rip singularity at infinite time.

Current acceleration may be the onset of phantom inflation.

Abstract

We study the phantom inflation in little rip cosmology, in which the current acceleration is driven by the field with the parameter of state w < -1, but since w tends to -1 asymptotically, the rip singularity occurs only at infinite time. In this scenario, before the rip singularity is arrived, the universe is in an inflationary regime. We numerically calculate the spectrum of primordial perturbation generated during this period and find that the results may be consistent with observations. This implies that if the reheating happens again, the current acceleration might be just a start of phantom inflation responsible for the upcoming observational universe.