Cosmological Constraints from Type Ia Supernovae Peculiar Velocity Measurements

TL;DR

This paper measures the correlated peculiar velocities of nearby Type Ia supernovae to constrain cosmological parameters, highlighting the importance of including peculiar velocity effects for accurate results.

Contribution

It provides the first detection of correlated peculiar velocities in nearby SNe and assesses their impact on cosmological parameter estimation.

Findings

Sigma_8=0.79 +/- 0.22 from SNe velocities

Ignoring peculiar velocities underestimates errors on w by about 35%

Demonstrates potential of SNe velocities to constrain cosmology in future surveys

Abstract

We detect the correlated peculiar velocities of nearby type Ia supernovae (SNe), while highlighting an error in some of the literature. We find sigma_8=0.79 +/- 0.22 from SNe, and examine the potential of this method to constrain cosmological parameters in the future. We demonstrate that a survey of 300 low-z SNe (such as the nearby SNfactory) will underestimate the errors on w by about 35% if the coherent peculiar velocities are not included.