Dark energy homogeneity in general relativity: are we applying it correctly? [CL]

http://arxiv.org/abs/1505.03436


Thusfar, there does not appear to be an agreed definition of homogeneous dark energy (DE). In this work, we argue that a correct definition of homogeneous DE is one whose density perturbation in comoving gauge vanishes. Using different DE models, we then investigate the consequence of this approach in the power spectrum — with all the power spectra being normalized to match each other on small scales, at z = 0. We find that on super-Hubble scales, relativistic corrections in the observed galaxy power spectrum are able to distinguish a homogeneous DE from the concordance model and from a clustering DE, at low z and for high magnification bias. However, the matter power spectrum: is incapable of distinguishing a homogeneous DE from the concordance model (on all scales), at z = 0; but is able to differentiate it from a clustering DE, particularly at low z. Moreover, we found that relativistic effects become enhanced with decreasing magnification bias, and with increasing z.

Read this paper on arXiv…

D. Duniya
Thu, 14 May 15
25/57

Comments: 10 pages, 6 figures. Submitted to Physical Review D