A number of challenges to the standard Λ CDM model have been emerging during the past
few years as the accuracy of cosmological observations improves. In this review we discuss …

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 …

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 …

We present results from an analysis of all data taken by the bicep2/Keck CMB polarization
experiments up to and including the 2015 observing season. This includes the first Keck …

Determining the origin of structure in the universe is one of the most important open
problems in cosmology. CMB anisotropies sourced by early-universe density perturbations …

A stochastic background of gravitational waves could be created by the superposition of a
large number of independent sources. The physical processes occurring at the earliest …

Abstract Models where dark matter and dark energy interact with each other have been
proposed to solve the coincidence problem. We review the motivations underlying the need …

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 …

The search for the curl component (B mode) in the cosmic microwave background (CMB)
polarization induced by inflationary gravitational waves is described. The canonical single …