SIMBAD references

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 ΛCDM 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 z: q₀=q_m+q_d.{^}n*exp(-z/S). The best fit to data yields q_d=-8.03 and S=0.0262 (=d∼100Mpc), rejecting isotropy (q_d=0) with 3.9σ statistical significance, while q_m=-0.157 and consistent with no acceleration (q_m=0) at 1.4σ. 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.