Dynamical Analysis in Chameleon Dark Energy

A detailed analysis of the phase-space for the field equations in scalar field cosmology with a chameleon cosmology in a spatially flat Friedmann-Lemaitre-Robertson-Walker spacetime is presented. For the matter source it is assumed that it is an ideal gas with a constant equation of state parameter, while for the scalar field potential and the coupling function of the chameleon mechanism it is considered that four different sets which provide four different models. The H-normalization approach and the field equations with the help of dimensionless variables written is considered. The asymptotic solutions are determined from where the theory can describe the main eras of cosmological history and evolution that are found. Future attractors which describe acceleration exist; however, acceleration solutions related to the inflationary era is found in past, as also the radiation epoch and the matter dominated eras are provided by the dynamics. The Chameleon dark energy model can be used as a unified model for the elements which contribute to the dark sector of the universe that are concluded.

Automated summary

A detailed analysis is presented on the phase-space for the field equations in scalar field cosmology with a chameleon cosmology. Four different sets of potential and coupling function are considered. The H-normalization approach and dimensionless variables are used to analyze the field equations. The asymptotic solutions describe the main eras of cosmological history and the existence of acceleration solutions. The Chameleon dark energy model is concluded to be a unified model for the dark sector of the universe.