Evidence for anisotropy of cosmic acceleration
  Observations reveal a `bulk flow' in the local Universe which is faster and
extends to much larger scales than is expected around a typical observer in the
standard $\Lambda$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 Lightcurve Analysis (JLA) 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 CMB
dipole which falls exponentially with redshift $z$: $q_0 = q_\mathrm{m} +
\vec{q}_\mathrm{d}.\hat{n}\exp(-z/S)$. The best fit to data yields
$q_\mathrm{d} = -8.03$ and $S = 0.0262~(\Rightarrow d \sim 100~\mathrm{Mpc})$,
rejecting isotropy ($q_\mathrm{d} = 0$) with $3.9\sigma$ statistical
significance, while $q_\mathrm{m} = -0.157$ and consistent with no acceleration
($q_\mathrm{m} = 0$) at $1.4\sigma$. 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.
