Cosmological scenarios from multiquintessence

R A C Correa,W De Paula,P H R S Moraes,J R L Santos,A De Souza Dutra

doi:10.1140/epjc/s10052-018-6361-4

Abstract

In this work we derive and analyse cosmological scenarios coming from multi-component scalar field models. We consider a direct sum of a sine-Gordon with a Z2 model, and also a combination of those with a BNRT model. Moreover, we work with a modified version of the BNRT model, which breaks the Z2 times Z2 symmetry of the original BNRT potential, coupled with the sine-Gordon and with the standard Z2 models. We show that our approach can be straightforwardly elevated to N fields. All the computations are made analytically and some parameters restriction is put forward in order to get in touch with complete and realistic cosmological scenarios.

Highlights

In standard cosmology model (SM), the quantum vacuum energy is the responsible for the cosmic acceleration observationally predicted [1,2]
The motivation to study this first example, where we have a mixture of sine-Gordon and Z2 models, comes from the fact that those are found in many areas of Physics, including condensed matter physics, field theory, cosmology, among many others
The main cosmological puzzle nowadays is to predict in a theoretical level the observed cosmic acceleration

Summary

Introduction

In standard cosmology model (SM), the quantum vacuum energy is the responsible for the cosmic acceleration observationally predicted [1,2]. It enters the field equations of General Relativity in the form of a cosmological constant (CC). There is a huge discrepancy between the theoretically predicted value for the vacuum quantum energy obtained via Particle Physics [3] and via observations [4]. Such a discrepancy yields the consideration of alternative gravity theories, from which healthy cosmological models can be derived.

A brief review of the first-order formalism

Model I

Model II

Model III

Cosmological parameters solutions

Discussion