Turning noise into signal: learning from the scatter in the Hubble diagram

Understand

The supernova (SN) Hubble diagram residual contains valuable information on both the present matter power spectrum and its growth history.

• In this paper we show that this information can be retrieved with precision by combining both peculiar velocity and weak-lensing analysis on the data.
• To wit, peculiar velocity induces correlations on the nearby SN while lensing induces a non-Gaussian dispersion in faraway objects.
• We show that both effects have almost orthogonal degeneracies and discuss how they can be extracted simultaneously from the data.