Understanding the reason for the observed accelerated expansion of the Universe
represents one of the fundamental open questions in physics. In cosmology, a classification …

We review recent progress in the construction of modified gravity models as alternatives to
dark energy as well as the development of cosmological tests of gravity. Einstein's theory of …

We identify a scalar-tensor model embedded in the Horndeski action whose cosmological
background and linear scalar fluctuations are degenerate with the concordance cosmology …

We present an accurate non-linear matter power spectrum prediction scheme for a variety of
extensions to the standard cosmological paradigm, which uses the tuned halo model …

Long range scalar fields with a coupling to matter appear to violate known bounds on
gravitation in the solar system and the laboratory. This is evaded thanks to screening …

The Novel Probes Project, an initiative to advance the field of astrophysical tests of the dark
sector by creating a forum that connects observers and theorists, is introduced. This review …

Shortly after its discovery, General Relativity (GR) was applied to predict the behavior of our
Universe on the largest scales, and later became the foundation of modern cosmology. Its …

The weak equivalence principle (WEP) is the cornerstone of general relativity (GR). Testing
it is thus a natural way to confront GR to experiments, which has been pursued for four …

As we are entering the era of precision cosmology, it is necessary to count on accurate
cosmological predictions from any proposed model of dark matter. In this paper we present a …

Future large scale structure surveys will provide increasingly tight constraints on our
cosmological model. These surveys will report results on the distance scale and growth rate …