Matter Growth in Imperfect Fluid Cosmology

Universe

HermanoE.S. Velten¹  WilliamC. Algoner²  Winfried Zimdahl³ 

[1] Núcleo Cosmo-UFES, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Campus de Goiabeiras, CEP 29075-910 Vitória, Espírito Santo, Brazil;Departamento de Física, Universidade Federal de Ouro Preto (UFOP), CEP 35400-000 Ouro Preto, Minas Gerais, Brazil;;PPGCosmo &

关键词: fluid cosmology;    cosmological perturbation theory;    scalar-tensor theory;    cosmic structure formation;   

DOI  :  10.3390/universe5030068

来源: DOAJ

【 摘 要 】

Extensions of Einstein’s General Relativity (GR) can formally be given a GR structure in which additional geometric degrees of freedom are mapped on an effective energy-momentum tensor. The corresponding effective cosmic medium can then be modeled as an imperfect fluid within GR. The imperfect fluid structure allows us to include, on a phenomenological basis, anisotropic stresses and energy fluxes which are considered as potential signatures for deviations from the cosmological standardΛ -cold-dark-matter ( Λ CDM) model. As an example, we consider the dynamics of a scalar-tensor extension of the standard model, thee ΦΛCDM model. We constrain the magnitudes of anisotropic pressure and energy flux with the help of redshift-space distortion (RSD) data for the matter growth function fσ 8 .

【 授权许可】

Unknown