Related papers: Cosmological constraints from large-scale structur…
We use the statistics of strong gravitational lensing based on the Cosmic Lens All-Sky Survey (CLASS) data to constrain cosmological parameters in a spatially-flat, inverse power-law potential energy density, scalar-field dark energy…
We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter $w$ that scales with the $\arctan$ of the redshift. The free parameters of the model are three constants: $\Omega_{b0}$,…
We present novel cosmological constraints based on a joint analysis of our HII galaxies (HIIG) Hubble relation with the full Planck Cosmic Microwave Background anisotropy spectrum and the Baryon Acoustic Oscillations (BAO) probes. The HII…
In previous papers, a cosmological model with constant-rate particle creation and vacuum term decaying linearly with the Hubble parameter was shown to lead to a good concordance when tested against precise observations: the position of the…
The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation…
The observed accelerated expansion of the Universe may be explained by dark energy or the breakdown of general relativity (GR) on cosmological scales. When the latter case, a modified gravity scenario, is considered, it is often assumed…
We investigate the possibility of measuring the Hubble constant, the fractional energy density components and the equation of state parameter of the ``dark energy'' using lensed multiple images of high-redshift supernovae. With future…
Directly comparing the 6 expansion rate measured by type Ia supernovae data and the lower bound on the expansion rate set by the strong energy conditions or the null hypothesis that there never exists cosmic acceleration, we see $3\sigma$…
We show that the spatial correlation of the intrinsic alignments (IAs) of galaxies, measured in galaxy redshift surveys, offers a precision route to improve the geometrical and dynamical constraints on cosmology. The IA has been treated as…
We present a cosmographic study designed to test the simplest type of accelerating cosmology: a flat universe with matter and a cosmological constant ($\Lambda$). Hubble series expansions are fit to the SCP Union2.1 supernova data set to…
The large-scale structure of the Universe and its evolution over time contains an abundance of cosmological information. One way to unlock this is by measuring the density and momentum power spectrum from the positions and peculiar…
The accelerating expansion of our universe at present could be driven by an unknown energy component (Dark Energy) or a modification of general relativity (Modified Gravity). In this note we revisit the constraints on a phenomenological…
The growth rate of cosmic structure is a powerful cosmological probe for extracting information on the gravitational interactions and dark energy. In the late time Universe, the growth rate becomes non-linear and is usually probed by…
In this paper we summarise the constraints that low-redshift data --such as supernovae Ia (SN Ia), baryon acoustic oscillations (BAO) and cosmic chronometers (CC)-- are able to set on the concordance model and its extensions, as well as on…
We use the redshift Hubble parameter $H(z)$ data derived from relative galaxy ages, distant type Ia supernovae (SNe Ia), the Baryonic Acoustic Oscillation (BAO) peak, and the Cosmic Microwave Background (CMB) shift parameter data, to…
Redshift space distortions caused by galaxy peculiar velocities provide a window onto the growth rate of large scale structure and a method for testing general relativity. We investigate through a comparison of N-body simulations to various…
Recent papers have shown that a small systematic redshift shift ($\Delta z\sim 10^{-5}$) in measurements of type Ia supernovae can cause a significant bias ($\sim$1\%) in the recovery of cosmological parameters. Such a redshift shift could…
We consider a very simple toy model for a spatially varying `cosmological constant', where we are inside a spherical bubble (with a given set of cosmological parameters) that is surrounded by a larger region where these parameters are…
One of the most compelling tasks of modern cosmology is to constrain the expansion history of the Universe, since this measurement can give insights on the nature of dark energy and help to estimate cosmological parameters. In this letter…
We use measurements of the galaxy-cluster angular size versus redshift to test and compare the standard model (LCDM) and the R_h=ct Universe. We show that the latter fits the data with a reduced chi^2_dof=0.786 for a Hubble constant H_0=…