$\Lambda$CDM Bounce Cosmology without $\Lambda$CDM: the case of modified gravity

TL;DR

This paper demonstrates that a $ ext{F}(R)$ gravity model can replicate the $ ext{Lambda}$CDM bounce cosmology without matter fluids or a cosmological constant, aligning with observational data and ensuring stability.

Contribution

It introduces a pure $ ext{F}(R)$ gravity framework that reproduces the $ ext{Lambda}$CDM bounce scenario, including inflationary and stability properties, without additional matter or cosmological constant.

Findings

The $ ext{F}(R)$ gravity model mimics $ ext{Lambda}$CDM bounce cosmology.

The model aligns with Planck observational data.

The stability and particle production aspects are thoroughly validated.

Abstract

We provide an $F(R)$ gravity description of a $\Lambda$CDM bouncing model, without the need for matter fluids or for cosmological constant. As we explicitly demonstrate, the two cosmological eras that constitute the $\Lambda$CDM bouncing model, can be generated by $F(R)$ gravity which can lead to accelerating cosmologies. The resulting F(R) gravity has Einstein frame inflationary properties that have concordance to the latest Planck observational data. Both the $F(R)$ gravity stability properties are thoroughly investigated and also, the gravitational particle production, a feature necessary for the viability of the $\Lambda$CDM bounce scenario, is also addressed. As we will show, the $\Lambda$CDM bounce model can be successfully described by pure $F(R)$ gravity, with appealing phenomenological attributes, which we extensively discuss.