相关论文: The growth index of matter perturbations and modif…
The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining the cosmic acceleration. The growth rate is parametrized by the growth index…
We study the linear growth of matter perturbations in the DGP model with the growth index $\gamma$ as a function of redshift. At the linear approximation: $\gamma(z)\approx\gamma_0+\gamma_0^\prime z $, we find that, for…
Measurements of the growth index $\gamma(z)$ provide a clue as to whether Einstein's field equations encompass gravity also on large cosmic scales, those where the expansion of the universe accelerates. We show that the information encoded…
We re-examine the growth index of the concordance $\Lambda$ cosmology in the light of the latest 6dF and {\em WiggleZ} data. In particular, we investigate five different models for the growth index $\gamma$, by comparing their cosmological…
The growth rate of matter perturbations can be used to distinguish between different gravity theories and to distinguish between dark energy and modified gravity at cosmological scales as an explanation to the observed cosmic acceleration.…
We study one of the simplest covariant modified-gravity models based on the Dvali-Gabadadze-Porrati (DGP) brane cosmology, a self-accelerating universe. In this model gravitational leakage into extra dimensions is responsible of late-time…
In this study, we analyse constraints on the growth index of matter perturbations, $\gamma$, within the framework of $f(Q)$ gravity, using recent cosmological observations, at the background and the perturbation levels, including…
In the literature, it was proposed that the growth index $\gamma$ is useful to distinguish the scenarios of dark energy and modified gravity. In the present work, we consider the constraints on the growth index $\gamma$ by using the latest…
Measurement of peculiar velocities by combining redshifts and distance indicators is a powerful way to measure the growth rate of cosmic structure and test theories of gravity at low redshift. Here we constrain the growth rate of structure…
We propose a parametrization for the growth index of the linear matter perturbations, $\gamma(z)=\gamma_0+\frac{z}{1+z}\gamma_1$. The growth factor of the perturbations parameterized as $\Omega_m^{\gamma}$ is analyzed for both the $w$CDM…
We study how the cosmological constraints from growth data are improved by including the measurements of bias from Dark Energy Survey (DES). In particular, we utilize the biasing properties of the DES Luminous Red Galaxies (LRGs) and the…
The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining cosmic acceleration. We explore here the inclusion of spatial curvature into the…
Alternative cosmological models have been proposed to alleviate the tensions reported in the concordance cosmological model, or to explain the current accelerated phase of the universe. One way to distinguish between General Relativity and…
The growth index $\gamma_L$ was proposed to investigate the possible deviation from the standard $\Lambda$CDM model and Einstein's gravity theory in a dynamical perspective. Recently, thanks to the measurement of the cosmic growth rate via…
We propose two improved parameterized form for the growth index of the linear matter perturbations: (I) $\gamma(z)=\gamma_0+(\gamma_{\infty}-\gamma_0){z\over z+1}$ and (II) $\gamma(z)=\gamma_0+\gamma_1…
Recently, some efforts focus on differentiating dark energy and modified gravity with the growth function $\delta(z)$. In the literature, it is useful to parameterize the growth rate $f\equiv d\ln\delta/d\ln a=\Omega_m^\gamma$ with the…
We use the clustering properties of Luminous Red Galaxies (LRGs) and the growth rate data provided by the various galaxy surveys in order to constrain the growth index ($\gamma$) of the linear matter fluctuations. We perform a standard…
We perform here a global analysis of the growth index $\gamma$ behaviour from deep in the matter era till the far future. For a given cosmological model in GR or in modified gravity, the value of $\gamma(\Omega_{m})$ is unique when the…
We use Luminous Red Galaxies from the Sloan Digital Sky Survey II to test the cosmological structure growth in two alternatives to the standard LCDM+GR cosmological model. We compare observed three-dimensional clustering in SDSS DR7 with…
The detailed nature of dark energy remains a mystery, leaving the possibility that its effects might be explained by changes to the laws of gravity on large scales. The peculiar velocities of galaxies directly trace the strength of gravity…