SNLS Projects

This page is somewhat out of date. See the published results here.

Predicted Effects

Hui & Green make a specific prediction of the effect of both weak lensing and peculiar velocities on the cosmology derived from the SNLS (see their figures 7 & 8, and table II). For an SNLS that produces 600 Type Ia SNe for fitting in a Hubble diagram the total degradation due to both weak lensing and correlated velocities is about 11% in the error on w.

They leave as an open question the possibility of correcting for these peculiar velocities, although their outlook on the feasability of this is somewhat pessimistic.

Mike Hudson has provided peculiar velocities for the SNe in the Astier et al. (2006) low-redshift sample. We used these to apply corrections to the sample and then calculate the total offset in Delta mu_B which amounts to 1.4%.

This plot focuses on the low-redshift part of the Hubble diagram from Astier et al. (2006). The corrections are computed using equations 11 and 13 from Hui & Green. The total offset of the corrected low redshift SN sample as compared with the uncorrected low redshift sample is 0.014 in mu_B.