Cosmological tests of gravity with latest observations
  We perform observational tests of modified gravity on cosmological scales
following model-dependent and model-independent approaches using the latest
astronomical observations, including measurements of the local Hubble constant,
cosmic microwave background, the baryonic acoustic oscillations and redshift
space distortions derived from galaxy surveys including the SDSS BOSS and
eBOSS, as well as the weak lensing observations performed by the CFHTLenS team.
Using all data combined, we find a deviation from the prediction of general
relativity in both the effective Newton's constant, $\mu(a,k)$, and in the
gravitational slip, $\eta(a,k)$. The deviation is at a $3.1\sigma$ level in the
joint $\{\mu(a,k),\eta(a,k)\}$ space using a two-parameter phenomenological
model for $\mu$ and $\eta$, and it reaches a $3.7\sigma$ level if a general
parametrisation is used. This signal, which may be subject to unknown
observational systematics, or a sign of new physics, is worth further
investigating with forthcoming observations.
