We review recent developments and results in testing general relativity (GR) at cosmological
scales. The subject has witnessed rapid growth during the last two decades with the aim of …

A century ago, Einstein formulated his elegant and elaborate theory of General Relativity,
which has so far withstood a multitude of empirical tests with remarkable success …

The dawn of the twenty-first century came with very positive prospects for gravity, cosmology,
and astrophysics. Technological progress made it possible for cosmology to enter to its …

The European Space Agency's Planck satellite, which was dedicated to studying the early
Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the …

We present cosmological parameter results from the final full-mission Planck measurements
of the cosmic microwave background (CMB) anisotropies, combining information from the …

Searching for violations of the no-hair theorem (NHT) is a powerful way to test gravity, and
more generally fundamental physics, particularly with regards to the existence of additional …

Astronomical observations reveal a major deficiency in our understanding of physics—the
detectable mass is insufficient to explain the observed motions in a huge variety of systems …

We present cosmological parameter results from the final full-mission Planck measurements
of the CMB anisotropies. We find good consistency with the standard spatially-flat 6 …

Gravitational waves (GWs) provide a new tool to probe the nature of dark energy (DE) and
the fundamental properties of gravity. We review the different ways in which GWs can be …

The gravitational wave (GW) event GW170817 from a binary neutron star merger together
with the electromagnetic counterpart showed that the speed of GWs ct is very close to that of …