Type Ia Supernovae and Weak Lensing : a window to matter-power on small-scales

SN Ia are weakly lensed by foreground inhomogeneity, making them brighter or dimmer depending on the line of sight. Historically, this has been treated as a noise term. I show that, through their correlation with foregrounds, the weak lensing of SN Ia is detectable and can be removed by an additional standardisation term. This increases the constraining power of observations at the transition from matter- to dark-energy dominated eras. 

Going further, I illustrate how the distribution of SN Ia residuals around their Hubble diagram fit opens a window to examine matter-power on scales smaller than those currently accessible to galaxy lensing. SN Ia data may be used to constrain dark matter halo properties, the presence of compact objects (such as primordial black holes), and the suppression or enhancement of matter-power on non-linear scales due to physics beyond cold dark matter.