@article {universe5030068,
	title = {Matter Growth in Imperfect Fluid Cosmology},
	journal = {Universe},
	volume = {5},
	number = {3},
	year = {2019},
	abstract = {Extensions of Einstein\&rsquo;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 standard \&Lambda; -cold-dark-matter ( \&Lambda; CDM) model. As an example, we consider the dynamics of a scalar-tensor extension of the standard model, the e \&Phi; \&Lambda; CDM 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 f \&sigma; 8 .},
	issn = {2218-1997},
	doi = {10.3390/universe5030068},
	url = {http://www.mdpi.com/2218-1997/5/3/68},
	author = {Zimdahl, Winfried and Velten, Hermano E.S. and Algoner, William C.}
}
