Measuring Baryon Acoustic Oscillations with Millions of Supernovae

TL;DR

This paper explores the potential of using large-scale photometric supernova surveys to measure baryon acoustic oscillations, offering a new method to probe cosmic structure and dark energy.

Contribution

It demonstrates that a half-sky photometric supernova survey can detect BAOs and improve dark energy constraints when combined with luminosity distance measurements.

Findings

SN BAOs can be measured up to z=0.8 with a half-sky survey.

SN BAOs provide complementary information to SN luminosity distances.

Combining SN BAOs with distances reduces dependence on CMB priors.

Abstract

Since type Ia Supernovae (SNe) explode in galaxies, they can, in principle, be used as the same tracer of the large-scale structure as their hosts to measure baryon acoustic oscillations (BAOs). To realize this, one must obtain a dense integrated sampling of SNe over a large fraction of the sky, which may only be achievable photometrically with future projects such as the Large Synoptic Survey Telescope. The advantage of SN BAOs is that SNe have more uniform luminosities and more accurate photometric redshifts than galaxies, but the disadvantage is that they are transitory and hard to obtain in large number at high redshift. We find that a half-sky photometric SN survey to redshift z = 0.8 is able to measure the baryon signature in the SN spatial power spectrum. Although dark energy constraints from SN BAOs are weak, they can significantly improve the results from SN luminosity distances of the same data, and the combination of the two is no longer sensitive to cosmic microwave background priors.