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Mohammad Malekjani

Mohammad Malekjani

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId: 36105022500
HIndex:
Faculty: Faculty of Science
Address:
Phone:

Research

Title
Cosmological constrains on minimally and non-minimally coupled scalar field models
Type
JournalPaper
Keywords
cosmology dark energy
Year
2020
Journal MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
DOI
Researchers ، Valerio Marra ، Mohammad Malekjani

Abstract

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 CDM model is strongly favoured when the local determination of the Hubble constant is not considered and that this statement is weakened once √ local H 0 is included in the analysis. We calculate the parameter combination S 8 = σ 8  m /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 and comparable to the conformal value ξ = 1/6 at 1σ uncertainty.