Related papers: An Upper Limit on Omega_matter Using Lensed Arcs
If dark matter in the form of compact objects comprises a large fraction of the mass of the universe, then gravitational lensing effects on gamma-ray bursts are expected. We utilize BATSE and Ulysses data to search for lenses of different…
The nature of dark matter and dark energy are among the central questions in cosmology. Strong gravitational lenses with multiple source planes provide a geometric probe of cosmology: the ratio of deflection angles at different redshifts…
The details of the CMB power spectrum are being revealed through the combined efforts of the world's CMBologists. The current data set constrains several cosmological parameters. A combination with other (non-lensing) constraints yields…
We use the abundance and weak lensing mass measurements of the SDSS maxBCG cluster catalog to simultaneously constrain cosmology and the richness--mass relation of the clusters. Assuming a flat \LambdaCDM cosmology, we find…
It is noticed that the total relative density of mass in the Universe Omega_tot should exceed 1, i.e. Omega_tot=1+f^2/6 according to the field relativistic theory of gravity (RTG), which is free of the cosmological singularity and which…
We report on the first measurement of the average mass and mass-to-light ratio of galaxy groups by analysing the weak lensing signal induced by these systems. The groups, which have velocity dispersions of 50-400 km/s, have been selected…
For a wide variety of cosmological models characterized by the cosmic mass density $\Omega_M$ and the normalized cosmological constant $\Omega_{\Lambda}$, we derive an analytic expression for the estimate of magnification cross-sections by…
We discuss the variation of cosmological upper bounds on $M_\nu$, the sum of the neutrino masses, with the choice of data sets included in the analysis, pointing out a few oddities not easily seen when all data sets are combined. For…
The concentrations of the cuspy dark matter halos predicted by simulations of cold dark matter are related to the cosmology in which the halos form. Observational constraints on halo concentration therefore map into constraints on…
We present constraints on the cosmological constant lambda_0 and the density parameter Omega_0 from joint constraints from the analyses of gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS), optical…
This work is related to different questions within cosmology. The principal idea herein is to develop cosmological knowledge making use of the analyses of observational data in order to find the values of the matter density Omega_m and…
The evolution of the galaxy cluster abundance depends sensitively on the value of the cosmological density parameter, Omega_0. Recent ASCA data are used to quantify this evolution as measured by the X-ray temperature function. A chi^2…
I show that three independent methods utilizing clusters of galaxies - cluster dynamics and mass-to-light ratio, baryon fraction in clusters, and cluster evolution - all indicate the same robust result: the mass-density of the universe is…
The existence of the three most massive clusters of galaxies observed so far at z>0.5 is used to constrain the mass density parameter of the universe, Omega, and the amplitude of mass fluctuations, sigma_8. We find Omega=0.2 (+0.3,-0.1),…
We assess a claim that observed galaxy clusters with mass ~10^14 Msun are more centrally concentrated than predicted in LCDM. We generate mock strong gravitational lensing observations, taking the lenses from a cosmological hydrodynamical…
Motivated by the significant overdensity of background bright quasars recently detected behind the foreground clusters of galaxies on scale of $10$ arcminutes, we have investigated the possibility of attributing the quasar-cluster…
We show that an expected number ratio of radial arcs (gravitationally lensed images whose major axes lie in the radial direction of a cluster-lens potential) to tangential arcs (gravitationally lensed images whose major axes lie in the…
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…
Extensive analyses of statistical strong gravitational lensing are performed based on the final Cosmic Lens All Sky Survey (CLASS) well-defined statistical sample of flat spectrum radio sources and current estimates of galaxy luminosity…
The statistics of wide-separation (6'' < theta < 15'') gravitational lenses constrain the amount of mass in the cores of dark matter halos on group and cluster mass scales. For a family of halo models with a central cusp $\rho \propto…