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Cosmological constrains on minimally and non-minimally coupled scalar field models

Davari, Z ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1093/mnras/stz3096
  3. Publisher: Oxford University Press , 2020
  4. Abstract:
  5. We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy (DE), the mysterious energy component that is driving the accelerated expansion of the universe. After discussing the dynamics at both the background and perturbation level, we confront the two models with the latest cosmological data. After obtaining updated constraints on their parameters, we perform model selection using the basic information criteria. We found that the ACDM model is strongly favoured when the local determination of the Hubble constant is not considered and that this statement is weakened once local H0 is included in the analysis. We calculate the parameter combination S8 = σ8 √Ωm/0.3 and show the decrement of the tension with respect to the Planck results in the case of minimally and non-minimally coupled scalar field models. Finally, for the coupling constant between DE and gravity, we obtain the constraint ξ ∼ - 0.06-0.19+0.19, approaching the one from Solar system tests |ξ | < 10-2, comparable to the conformal value ξ = 1/6 at 1σ uncertainty. © 2019 The Author(s)
  6. Keywords:
  7. Cosmology: theory ; Dark energy ; Methods: analytical
  8. Source: Monthly Notices of the Royal Astronomical Society ; Volume 491, Issue 2 , 2020 , Pages 1920-1933
  9. URL: https://academic.oup.com/mnras/article/491/2/1920/5612228