%0 Journal Article
%T Evidence for anisotropy of cosmic acceleration
%A Jacques Colin
%A Mohamed Rameez
%A Roya Mohayaee
%A Subir Sarkar
%J -
%D 2019
%R 10.1051/0004-6361/201936373
%X Observations reveal a ¡°bulk flow¡± in the local Universe which is faster and extends to much larger scales than are expected around a typical observer in the standard ¦«CDM cosmology. This is expected to result in a scale-dependent dipolar modulation of the acceleration of the expansion rate inferred from observations of objects within the bulk flow. From a maximum-likelihood analysis of the Joint Light-curve Analysis catalogue of Type Ia supernovae, we find that the deceleration parameter, in addition to a small monopole, indeed has a much bigger dipole component aligned with the cosmic microwave background dipole, which falls exponentially with redshift <i>z<i/>: . The best fit to data yields <i>q<i/><sub>d<sub/>£¿=£¿£¿8.03 and <i>S<i/>£¿=£¿0.0262 (£¿<i>d<i/>£¿¡«£¿100£¿Mpc), rejecting isotropy (<i>q<i/><sub>d<sub/>£¿=£¿0) with 3.9<i>¦Ò<i/> statistical significance, while <i>q<i/><sub>m<sub/>£¿=£¿£¿0.157 and consistent with no acceleration (<i>q<i/><sub>m<sub/>£¿=£¿0) at 1.4<i>¦Ò<i/>. Thus the cosmic acceleration deduced from supernovae may be an artefact of our being non-Copernican observers, rather than evidence for a dominant component of ¡°dark energy¡± in the Universe
%U https://www.aanda.org/articles/aa/full_html/2019/11/aa36373-19/aa36373-19.html