Related papers: Lambda_0 and Omega_0 from Lensing Statistics and O…
I present constraints on cosmological parameters in the lambda_0-Omega_0 plane from a joint analysis of gravitational lensing statistics (astro-ph/9904175) and the magnitude-redshift relation for Type Ia supernovae (astro-ph/9812133 and…
The $m$-$z$ relation for type Ia supernovae is one of the key pieces of evidence supporting the cosmological `concordance model' with $\lambda_0 \approx 0.7$ and $\Omega_0 \approx 0.3$. However, it is well known that the $m$-$z$ relation…
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…
I review simultaneous constraints on the cosmological parameters lambda_0 and Omega_0 from gravitational lensing. The emphasis is on systematic extragalactic surveys for strong gravitational lenses, mainly the largest and best-defined such…
Strong gravitational lensing has traditionally been one of the few phenomena said to oppose a large cosmological constant; many analyses of lens statistics have given upper limits on $\Omega_\Lambda$ that are marginally inconsistent with…
We investigate observational constraints from lensing statistics and high-z type Ia supernovae on flat cosmological models with nonrelativistic matter and an exotic fluid with equation of state, $p_x=(m/3 -1)\rho_x$. We show that agreement…
We reanalyse optical gravitational lens surveys from the literature in order to determine relative probabilities in the $\lambda_{0}$-$\Omega_{0}$ plane, using a softened singular isothermal sphere lens model. In addition, we examine a…
I present several simple figures to illustrate cosmology and structure formation in a nutshell. Then I discuss the following argument: if we assume that Omega_{Lambda} = 0 then the CMB results favor high Omega_{m} while the supernova…
The distance-redshift relation depends on the amount of matter of each type in the universe. Measurements at different redshifts constrain differing combinations of these matter densities and thus may be used in combination to constrain…
In the pre-WMAP, pre-Supernova-Ia-Hubble-diagram era, quasar lensing statistics stubbornly indicated low values of Omega_Lambda. In contrast, a number of recent lensing statistics studies either find the data support the standard Lambda-CDM…
Constraints on an exact quintessence scalar-field model with an exponential potential are derived from gravitational lens statistics. An exponential potential can account for data from both optical quasar surveys and radio selected sources.…
The $m$-$z$ relation for Type Ia supernovae is compatible with the cosmological concordance model if one assumes that the Universe is homogeneous, at least with respect to light propagation. This could be due to the density along each line…
In this paper we investigate the statistical properties of gravitational lenses for models in which a cosmological term decreases with time as $\Lambda \propto a^{-m}$, where $a$ is the scale factor and $m$ is a parameter ($0 \leq m < 3$).…
We combine the Cosmic Lens All-Sky Survey (CLASS) with new Sloan Digital Sky Survey (SDSS) data on the local velocity dispersion distribution function of E/S0 galaxies, $\phi(\sigma)$, to derive lens statistics constraints on…
I use the most recent cosmic microwave background (CMB) anisotropy measurements to constrain the leading cold dark matter models in the Omega_m - Omega_lambda plane. A narrow triangular region is preferred. This triangle is elongated in…
In this paper, we use three different kinds of observational data, including 130 strong gravitational lensing (SGL) systems, type Ia supernovae (SNeIa: Pantheon and Union2.1) and 31 Hubble parameter data points ($H(z)$) from cosmic…
We use a strong lensing inversion in the cluster of galaxies AC 114 to derive constraints on the cosmological parameters Omega_M0 and Omega_Lambda. If it is possible to measure spectroscopically the redshifts of many multiple images then…
Gravitational lensing information from the two and higher point statistics of the CMB temperature and polarization fields are intrinsically correlated because they are lensed by the same realization of structure between last scattering and…
Following the recent measurement of the acoustic peak by the BOOMERanG and MAXIMA experiments in the CMB anisotropy angular power spectrum, many analyses have found that the geometry of the Universe is very close to flat, but slightly…
The evidence for positive cosmological constant $\Lambda$ from Type Ia supernovae is reexamined. Both high redshift supernova teams are found to underestimate the effects of host galaxy extinction. The evidence for an absolute magnitude-…