Pilar Ruiz-Lapuente

Measurements of Omega and Lambda from 42 high redshift supernovae

We report measurements of the mass density, Omega_M, and cosmological-constant energy density, Omega_Lambda, of the universe based on the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these SNe, at redshifts between 0.18 and 0.83, are fit jointly with a set of SNe from the Calan/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. All SN peak magnitudes are standardized using a SN Ia lightcurve width-luminosity relation. The measurement yields a joint probability distribution of the cosmological parameters that is approximated by the relation 0.8 Omega_M - 0.6 Omega_Lambda ~= -0.2 +/- 0.1 in the region of interest (Omega_M 0) = 99%, including the identified systematic uncertainties. The best-fit age of the universe relative to the Hubble time is t_0 = 14.9{+1.4,-1.1} (0.63/h) Gyr for a flat cosmology. The size of our sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We find no significant differences in either the host reddening distribution or Malmquist bias between the low-redshift Calan/Tololo sample and our high-redshift sample. The conclusions are robust whether or not a width-luminosity relation is used to standardize the SN peak magnitudes.

New constraints on Omega(M), Omega(lambda), and w from an independent set of eleven high-redshift supernovae observed with HST

We report measurements of

Spectra and hubble space telescope light curves of six typE Ia supernovae at 0.511 < z < 1.12 and the union2 compilation

\Omega_M

The Sloan Digital Sky Survey - II:supernova survey: technical summary

,

Timescale stretch parameterization of Type Ia supernova B-band light curves

\Omega_\Lambda

New Constraints on ΩM, ΩΛ, and w from an Independent Set of 11 High-Redshift Supernovae Observed with the Hubble Space Telescope*

, and w from eleven supernovae at z=0.36-0.86 with high-quality lightcurves measured using WFPC-2 on the HST. This is an independent set of high-redshift supernovae that confirms previous supernova evidence for an accelerating Universe. Combined with earlier Supernova Cosmology Project data, the new supernovae yield a flat-universe measurement of the mass density

High-Velocity Features: A Ubiquitous Property of Type Ia Supernovae

\Omega_M=0.25^{+0.07}_{-0.06}

SN 2003du: 480 days in the life of a normal type Ia supernova

(statistical)

SN 2004aw: confirming diversity of Type Ic supernovae

\pm0.04

Variable cosmological constant as a Planck scale effect

(identified systematics), or equivalently, a cosmological constant of