Related papers: A cosmological test for general relativity
Deviations from general relativity, such as could be responsible for the cosmic acceleration, would influence the growth of large scale structure and the deflection of light by that structure. We clarify the relations between several…
We derive the effects of a non-zero cosmological constant $\Lambda$ on gravitational wave propagation in the linearized approximation of general relativity. In this approximation we consider the situation where the metric can be written as…
We study a Newtonian cosmological model in the context of a noncommutative space. It is shown that the trajectories of a test particle undergo modifications such that it no longer satisfies the cosmological principle. For the case of a…
The cosmic microwave background (CMB) offers a unique window into the early universe, providing insights into cosmological parameters like the Hubble constant. Recent precise measurements of the CMB by experiments like Planck seem to point…
The Cosmic Microwave Background (CMB) provides a precious window on fundamental physics at very high energy scales, possibly including quantum gravity, GUTs and supersymmetry. The CMB has already enabled defect-based rivals to inflation to…
WMAP observations have accurately determined the position of the first two peaks and dips in the CMB temperature power spectrum. These encode information on the ratio of the distance to the last scattering surface to the sound horizon at…
Location dependence of physical parameters such as the electromagnetic fine structure constant and Newton's G produce body accelerations which violate universality of free fall rates testable with laboratory and space experiments.…
Recent measurements of the cosmic microwave background radiation (CMB), particularly when combined with other datasets, have revolutionised our knowledge of the values of the basic cosmological parameters. Here we summarize the state of…
We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-$\alpha$ forest and the Cosmic Microwave Background are used to set…
We build a minimal extension of General Relativity in which Newton's gravitational coupling, $G$, the speed of light, $c$, and the cosmological constant, $\Lambda$, are spacetime variables. This is done while satisfying the contracted…
We review the status of neutrino mass constraints obtained from cosmological observations, with a particular focus on the results derived considering Cosmic Microwave Background (CMB) data by various experiments (Planck, ACT and SPT),…
Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately…
We present the first joint-likelihood analysis of Big Bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) data. Bayesian inference is performed on the baryon abundance and the effective number of neutrino species, $N_{\rm…
We review the current cosmological status of neutrinos, with particular emphasis on their effects on Big Bang Nucleosynthesis, Large Scale Structure of the universe and Cosmic Microwave Background Radiation measurements.
We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…
Big bang nucleosynthesis has long provided the primary determination of the cosmic baryon density $\omb h^2$, or equivalently the baryon-to-photon ratio, \eta. Recently, data on CMB anisotropies have become increasingly sensitive to \eta.…
Age consistency for the Universe today has been an important cosmological test. Even more powerful consistency tests at times as early as 10^{-32} sec lie ahead in the precision era of cosmology. I outline tests based upon cosmic microwave…
We show that the first year results of the Wilkinson Microwave Anisotropy Probe (WMAP) constrain very efficiently the energy density in relativistic particles in the universe. We derive new bounds on additional relativistic degrees of…
Nowadays, thanks to the improved precision of cosmological data, it has been possible to search for deviation from the general relativity theory with tests on large cosmic scales. Particularly, there is a class of modified gravity theories…
We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are allowed to be highly non-linear, and the…