Effect of dark energy sound speed and equation of state on CDM power spectrum

Abstract

We study the influence of equation of state $w$ and effective sound speed $c_e$ of the dark energy perturbations on the cold dark matter(CDM) power spectrum.We consider different cases of the equation of state and the effective sound speed, the cold dark matter power spectrum is found to be generically suppressed in these cases as compared to the $\Lambda$CDM model. The suppression at different length scales depends on the value of $w$ and $c_e$, and the effect of different $w$ is profoundly seen at all length scales. The influence of sound speed is significantly seen only at the intermediate length scales and is negligible at scales very much larger and smaller than the Hubble scale.

arXiv commentBased on the poster presented at the 7th International Conference on Gravitation and Cosmology (ICGC2011), Goa, December 14 - 19, 2011: Contribution to the proceedings for the same

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• Reconstructing the dark energy potential
• Full Investigation on the Dynamics of Power-Law Kinetic Quintessence
• Sound speed of scalar field dark energy: weak effects and large uncertainties
• Dark energy homogeneity in general relativity: Are we applying it correctly?
• A varying Dark Energy effective speed of sound parameter in the phantom Universe