Related papers: Using bright ellipticals as dark energy cosmic clo…
Probing the evolution of the universe at high redshifts with standard candles is a powerful way to discriminate dark energy models, where an open question nowadays is whether this component is constant or evolves with time. One possible…
The amount and nature of dark energy (DE) can be tightly constrained by measuring the spatial correlation features and evolution of a sample of ~ 100,000 galaxy clusters over the redshift range 0<z < 1.5. Such an X-ray survey will discover…
Galaxy clusters at high redshift present a superb opportunity to study galaxy evolution, with large galaxy samples at fixed distances. Several lines of evidence point towards large formation redshifts and passive evolution for cluster…
We present a thorough quantitative analysis of the evolution of the colour-magnitude relation for early-type galaxies in 17 distant clusters with redshifts 0.31 < z < 1.27 using the Kodama & Arimoto (1997) evolutionary model for elliptical…
We present the cosmological parameters constraints obtained from the combination of galaxy cluster mass function measurements (Vikhlinin et al., 2009a,b) with new cosmological data obtained during last three years: updated measurements of…
We present a study of the color evolution of elliptical and S0 galaxies in six clusters of galaxies inside the redshift range 0.78 < z < 1.27. For each cluster, we used imaging from the Hubble Space Telescope to determine morphological…
[Abridged] We use data on massive galaxy clusters ($M_{\rm cluster} > 8 \times 10^{14} h^{-1} M_\odot$ within a comoving radius of $R_{\rm cluster} = 1.5 h^{-1}\Mpc$) in the redshift range $0.05 \lesssim z \lesssim 0.83$ to place…
We study the utility of a large sample of type Ia supernovae that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider information from the traditional luminosity…
Massive galaxy clusters at intermediate redshifts act as gravitational lenses that can magnify supernovae (SNe) occurring in background galaxies. We assess the possibility to use lensed SNe to put constraints on the mass models of galaxy…
Using the nonextensive Tsallis entropy and the holographic hypothesis, we propose a new dark energy (DE) model with time scale as infrared (IR) cutoff. Considering the age of the Universe as well as the conformal time as IR cutoffs, we…
Type Ia supernovae (SNIa) play a central role in constraining the late-time expansion history of the Universe and are directly implicated in current cosmological tensions. Motivated by the possibility of unaccounted redshift-dependent…
In this paper we analyze the constraints on the property of dark energy from cosmological observations. Together with SNe Ia Gold sample, WMAP, SDSS and 2dFGRS data, we include 69 long Gamma-Ray Bursts (GRBs) data in our study and perform…
The magnitude-redshift relation is one of the tools for a direct observational approach to cosmology. The discovery of high redshift Type Ia supernovae (SNIa) and their use as ``standard candles'' has resurrected interest in this approach.…
In this paper we use H II starburst galaxy apparent magnitude versus redshift data from Siegel et al. (2005) to constrain dark energy cosmological model parameters. These constraints are generally consistent with those derived using other…
In this paper, we constrain dark energy models using a compendium of observations at low redshifts. We consider the dark energy as a barotropic fluid, with the equation of state a constant as well the case where dark energy equation of…
We discuss a new method which is potentially capable of constraining cosmological parameters using observations of giant luminous arcs in rich X-ray clusters of galaxies. The mass profile and the mass normalization of the lenses are…
New ground-based and HST observations of distant clusters make it possible to trace the history of E/S0 galaxies to lookback times of ~10 $h_{50}^{-1}$ Gyr. The data strongly favor a scenario in which cluster ellipticals formed very early…
A simple chemical enrichment model for cluster early-type galaxies is described in which the mechanisms considered in the evolutionary model are infall of primordial gas, outflows and a possible variation in the star formation efficiency.…
We present a summary of our project that studies galaxies hosting type Ia supernova (SN Ia) at different redshifts. We present Gran Telescopio de Canarias (GTC) optical spectroscopy of six SN Ia host galaxies at redshift $z\sim 0.4-0.5$.…
The recently published analytic probability density function for the mildly non-linear cosmic density field within spherical cells is used to build a simple but accurate maximum likelihood estimate for the redshift evolution of the variance…