Impact of dark energy perturbations on the growth index

2014/03/31 by Ronaldo C. Batista · 5 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Astrophysics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Omega #Parametrization (atmospheric modeling) #Physics #Quantum mechanics #Quintessence #Radiative transfer #Redshift #Spectral index #astro-ph.CO

paper · pdf · doi:10.1103/physrevd.89.123508

published as Phys. Rev. D 89, 123508 (2014) · 7 pages, 6 figures, minor changes, matches the accepted version in Phys. Rev. D

openalex publication_date 2014/06/13 · arxiv created 2014/07/07 · arxiv updated 2014/07/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We show that in clustering dark energy models the growth index of linear matter perturbations, \ensuremathγ, can be much lower than in \mathrm\ensuremathΛCDM or smooth quintessence models and presents a strong variation with redshift. We find that the impact of dark energy perturbations on \ensuremathγ is enhanced if the dark energy equation of state has a large and rapid decay at low redshift. We study four different models with these features and show that we may have 0.33<\ensuremathγ(z)<0.48 at 0<z<3. We also show that the constant \ensuremathγ parametrization for the growth rate, f=d ln\ensuremathδ_m/d lna=\mathrm\ensuremathΩ_m^\ensuremathγ, is a few percent inaccurate for such models and that a redshift-dependent parametrization for \ensuremathγ can provide about four times more accurate fits for f. We discuss the robustness of the growth index to distinguish between general relativity with clustering dark energy and modified gravity models, finding that some f(R) and clustering dark energy models can present similar values for \ensuremathγ.

Citations

• A parametrization for the growth index of linear matter perturbations
• Dark Energy versus Modified Gravity
• Atypicalk-essence cosmologies
• The Essence of Quintessence and the Cost of Compression
• The effective theory of quintessence: thew< −1 side unveiled
• Accelerating Universes with Scaling Dark Matter
• Dispersion of growth of matter perturbations inf(R)gravity
• Kinetically driven quintessence
• Distinguishing modified gravity from dark energy

Cited by

• Clustering dark energy and halo abundances
• Nonlinear dark matter collapse under diffusion
• Dark energy homogeneity in general relativity: Are we applying it correctly?
• Can holographic dark energy models fit the observational data?
• Growth of matter perturbations in the extended viscous dark energy models

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• Implications of a high growth index on the variation of G