Related papers: Global Cosmological Parameters Determined Using Cl…
Using the narrow clustering of the geometrically corrected gamma-ray energies released by gamma-ray bursts, we investigate the possibility of using these sources as standard candles to probe cosmological parameters such as the matter…
We have derived new bounds on the relativistic energy density in the Universe from cosmic microwave background (CMB), large scale structure (LSS), and type Ia supernova (SNI-a) observations. In terms of the effective number of neutrino…
We study the morphology of the radio emission of giant radio galaxies (GRGs), a rare type of active galaxies, in order to find new clues for the reasons of their large size. Using radio images from two sky surveys at 1.4 GHz we quantified…
In this work, we use two gas mass fraction samples of galaxy clusters obtained from their X-ray surface brightness observations jointly with recent $H(z)$ data in a flat $\Lambda$CDM framework to impose limits on cosmic opacity. It is…
Despite the fact that the mean matter density of the universe has been measured to an accuracy of a few percent within the standard $\Lambda$CDM paradigm, its median density is not known even to order of magnitude. Typical points lie in…
Ultra-steep spectrum (USS) radio sources are good tracers of powerful radio galaxies at $z > 2$. Identification of even a single bright radio galaxy at $z > 6$ can be used to detect redshifted 21cm absorption due to neutral hydrogen in the…
We present the constraints on the cosmological parameters obtained with the $E_{\rm peak}$--$E_{\gamma}$ correlation found with the most recent sample of 19 GRBs with spectroscopically measured redshift and well determined prompt emission…
We present a cosmic shear analysis of the 100 square degree weak lensing survey, combining data from the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ~100 square degrees, with a median source redshift z~0.78, this combined…
We use the existing catalog of Damped Lyman-Alpha (DLA) systems to place constraints on the amount of evolution in the baryonic content of galaxies and on the value of the cosmological constant. The density of cold gas at redshifts z=3+-1…
We have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($\alpha…
Observational constraints to a large class of decaying vacuum cosmologies are derived using the angular size data of compact radio sources and the latest age estimates of globular clusters. For this class of deflationary $\Lambda(t)$…
We present cosmological constraints from the Dark Energy Survey (DES) using a combined analysis of angular clustering of red galaxies and their cross-correlation with weak gravitational lensing of background galaxies. We use a 139 square…
The JVAS (Jodrell Bank-VLA Astrometric Survey) and CLASS (Cosmic Lens All-Sky Survey) are well-defined surveys containing about ten thousand flat-spectrum radio sources. For many reasons, flat-spectrum radio sources are particularly…
The Star Formation Rate Density (SFRD) history of the Universe is well constrained up to redshift $z \sim 2$. At earlier cosmic epochs, the picture has been largely inferred from UV-selected galaxies (e.g. Lyman-break galaxies, LBGs).…
We investigate the properties and the environment of radio sources with optical counterpart from the combined VLA-COSMOS and zCOSMOS samples. The advantage of this sample is the availability of optical spectroscopic information, high…
Combining cosmological probes has consolidated the standard cosmological model with percent precision, but some tensions have recently emerged when certain parameters are estimated from the local or primordial Universe. The origin of this…
We present a study of the baryonic fraction in galaxy clusters aimed at constraining the cosmological parameters Omega_m, Omega_Lambda and the ratio between the pressure and density of the ``dark'' energy, w. We use results on the…
The parameters of cosmological model with cold dark matter and cosmological constant (Lambda CDM) have been determined on a basis of three-year cosmic microwave background observations by space mission WMAP, as well as the data on the…
We use HII starburst galaxy apparent magnitude measurements to constrain cosmological parameters in six cosmological models. A joint analysis of HII galaxy, quasar angular size, baryon acoustic oscillations peak length scale, and Hubble…
We present measurements of both scale- and time-dependent deviations from the standard gravitational field equations. These late-time modifications are introduced separately for relativistic and non-relativistic particles, by way of the…