Clustering of quintessence on horizon scales and its imprint on HI intensity mapping
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Science
Abstract
Quintessence can cluster only on horizon scales. What is the effect on the observed matter distribution? To answer this, we need a relativistic approach that goes beyond the standard Newtonian
calculation and deals properly with large scales. Such an approach has recently been developed for
the case when dark energy is vacuum energy, which does not cluster at all. We extend this relativistic analysis to deal with dynamical dark energy. Using three quintessence potentials as examples,
we compute the angular power spectrum for the case of an HI intensity map survey. Compared to
the concordance model with the same small-scale power at z = 0, quintessence boosts the angular
power by up to 15% at high redshifts, while power in the two models converges at low redshifts.
The difference is mainly due to the background evolution, driven mostly by the normalization of the
power spectrum today. The dark energy perturbations make only a small contribution on the largest
scales, and a negligible contribution on smaller scales. Ironically, the dark energy perturbations remove the false boost of large-scale power that arises if we impose the (unphysical) assumption that
the dark energy is smooth.
Description
Keywords
Quintessence, Horizon scales, HI intensity mapping, Dark energy perturbations
Citation
Duniya, D.G.A. et al. (2013). Clustering of quintessence on horizon scales and its imprint on HI intensity mapping. Journal of Cosmology and Astroparticle Physics, 10