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f(R) gravity k-Essence late-time phenomenology

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dc.contributor.author Odintsov S.D.
dc.contributor.author Oikonomou V.K.
dc.contributor.author Fronimos F.P.
dc.date.accessioned 2021-02-25T21:01:02Z
dc.date.available 2021-02-25T21:01:02Z
dc.date.issued 2020
dc.identifier.issn 2212-6864
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/162879
dc.description.abstract © 2020 Elsevier B.V. In this work we shall study the late-time behavior of k-Essence f(R) gravity without scalar potential, in the presence of matter and radiation perfect fluids. We quantify the late-time study by using the statefinder function [Formula presented], which is a function of the redshift and of the Hubble rate. By appropriately rewriting the Friedmann equation in terms of the redshift and of the function YH(z), we numerically solve it using appropriate initial conditions, and we critically examine the effects of the k-Essence higher order kinetic terms. As we demonstrate, the effect of the higher order scalar field kinetic terms on the late-time dynamics is radical, since the dark energy oscillations are absent, and in addition, the cosmological physical quantities are compatible with the latest Planck data and also the model is almost indistinguishable from the Λ Cold Dark Matter model. This is in contrast to the standard f(R) gravity case, where the oscillations are present. Furthermore, by choosing a different set of values of two of the free parameters of the model, and specifically the coefficient of the higher order kinetic term and of the exponent of Rδ appearing in the f(R) action, we demonstrate that it is possible to obtain ρDE<0 for redshifts z∼2−3.8, which complies phenomenologically with, and seems to explain, the observational data for the same redshifts, and also to obtain a viable cosmological evolution at z∼0, at least when the dark energy equation of state parameter and the dark energy density parameters are considered.
dc.relation.ispartofseries Physics of the Dark Universe
dc.title f(R) gravity k-Essence late-time phenomenology
dc.type Article
dc.relation.ispartofseries-volume 29
dc.collection Публикации сотрудников КФУ
dc.source.id SCOPUS22126864-2020-29-SID85083494449


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  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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