TY - JOUR
T1 - Are dark energy models with variable EoS parameter w compatible with the late inhomogeneous Universe?
AU - Akarsu, Özgür
AU - Bouhmadi-López, Mariam
AU - Brilenkov, Maxim
AU - Brilenkov, Ruslan
AU - Eingorn, Maxim
AU - Zhuk, Alexander
N1 - Publisher Copyright:
© 2015 IOP Publishing Ltd and Sissa Medialab srl .
PY - 2015/7/1
Y1 - 2015/7/1
N2 - We study the late-time evolution of the Universe where dark energy (DE) is presented by a barotropic fluid on top of cold dark matter (CDM) . We also take into account the radiation content of the Universe. Here by the late stage of the evolution we refer to the epoch where CDM is already clustered into inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies). Under this condition the mechanical approach is an adequate tool to study the Universe deep inside the cell of uniformity. More precisely, we study scalar perturbations of the FLRW metric due to inhomogeneities of CDM as well as fluctuations of radiation and DE. For an arbitrary equation of state for DE we obtain a system of equations for the scalar perturbations within the mechanical approach. First, in the case of a constant DE equation of state parameter w, we demonstrate that our method singles out the cosmological constant as the only viable dark energy candidate. Then, we apply our approach to variable equation of state parameters in the form of three different linear parametrizations of w, e.g., the Chevallier-Polarski-Linder perfect fluid model. We conclude that all these models are incompatible with the theory of scalar perturbations in the late Universe.
AB - We study the late-time evolution of the Universe where dark energy (DE) is presented by a barotropic fluid on top of cold dark matter (CDM) . We also take into account the radiation content of the Universe. Here by the late stage of the evolution we refer to the epoch where CDM is already clustered into inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies). Under this condition the mechanical approach is an adequate tool to study the Universe deep inside the cell of uniformity. More precisely, we study scalar perturbations of the FLRW metric due to inhomogeneities of CDM as well as fluctuations of radiation and DE. For an arbitrary equation of state for DE we obtain a system of equations for the scalar perturbations within the mechanical approach. First, in the case of a constant DE equation of state parameter w, we demonstrate that our method singles out the cosmological constant as the only viable dark energy candidate. Then, we apply our approach to variable equation of state parameters in the form of three different linear parametrizations of w, e.g., the Chevallier-Polarski-Linder perfect fluid model. We conclude that all these models are incompatible with the theory of scalar perturbations in the late Universe.
KW - cosmological perturbation theory
KW - dark energy theory
UR - http://www.scopus.com/inward/record.url?scp=84938323233&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2015/07/038
DO - 10.1088/1475-7516/2015/07/038
M3 - Article
AN - SCOPUS:84938323233
SN - 1475-7516
VL - 2015
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 7
M1 - 038
ER -