Acceleration of the Universe driven by the Casimir force

TL;DR

This paper explores a cosmological model where the universe's acceleration is driven by the Casimir force, analyzing its dynamics, solutions, and observational fit compared to the standard Lambda-CDM model.

Contribution

It introduces a detailed dynamical system analysis of a universe driven by Casimir energy, providing exact solutions and comparing its observational viability to Lambda-CDM.

Findings

The Casimir-driven model exhibits bouncing and initial singularity solutions.

Bayesian analysis favors the Lambda-CDM model over the Casimir model.

Negative radiation-like terms may reconcile primordial element abundances.

Abstract

We investigate an evolutional scenario of the FRW universe with the Casimir energy scaling like $(-)(1+z)^4$. The Casimir effect is used to explain the vacuum energy differences (its value measured from astrophysics is so small compared to value obtained from quantum field theory calculations). The dynamics of the FRW model is represented in terms of a two-dimensional dynamical system to show all evolutional paths of this model in the phase space for all admissible initial conditions. We find also an exact solution for non flat evolutional paths of Universe driven by the Casimir effect. The main difference between the FRW model with the Casimir force and the $\Lambda$CDM model is that their generic solutions are a set of evolutional paths with a bounce solution and an initial singularity, respectively. The evolutional scenario are tested by using the SNIa data, FRIIb radiogalaxies, baryon oscillation peak and CMB observation. We compare the power of explanation of the model considered and the $\Lambda$CDM model using the Bayesian information criterion and Bayesian factor. Our investigation of the information criteria of model selection showed the preference of the $\Lambda$CDM model over the model considered. However the presence of negative like the radiation term can remove a tension between the theoretical and observed primordial ${}^4$He and D abundance.