http://arxiv.org/abs/1602.01389
We investigate the validity of the Cosmological Principle by constraining the cosmological parameters $H_0$ and $q_0$ through the celestial sphere. Our analyses are performed in a low-redshift regime in order to follow a model independent approach, using both Union2.1 and JLA Type Ia Supernovae (SNe) compilations. We find that the preferred direction of the $H_0$ parameter in the sky is consistent with the bulk flow motion of our local Universe in the Union2.1 case, while the $q_0$ directional analysis seem to be anti-correlated with the $H_0$ for both data sets. Furthermore, we test the consistency of these results with Monte Carlo (MC) realisations, finding that the anisotropy on both parameters are significant within $2-3\sigma$ confidence level, albeit we find a significant correlation between the $H_0$ and $q_0$ mapping with the angular distribution of SNe from the JLA compilation. Therefore, we conclude that the detected anisotropies are either of local origin, or induced by the non-uniform celestial coverage of the SNe data set.
C. Bengaly, A. Bernui and J. Alcaniz
Thu, 4 Feb 16
10/50
Comments: 6 pages, 6 figures; Contribution to the proceedings of the “The Fourteenth Marcel Grossmann Meeting on General Relativity”, University of Rome “La Sapienza”, Rome, July 12-18, 2015, based on talk delivered at the DE1 parallel session, in addition to the results from C. A. P. Bengaly, A. Bernui and J. S. Alcaniz, ApJ 808 (2015) 39 (arXiv:1503.01413 [astro-ph.CO])