Improved distance measurements using twin supernovae from SNfactory

The Nearby Supernova Factory (Aldering, et al. 2002) has collected spectrophotometric timeseries of many Hubble-flow type Ia supernovae. Using this dataset, we discuss a novel method of standardizing supernovae by finding "twin" supernovae with matching spectral data. The analysis uses Gaussian processes to interpolate data from supernovae, and matches them up, allowing only relative dust extinction. We find that the best spectral twins have a much lower dispersion in relative brightness than the overall sample. We demonstrate both the usage of this method and the data requirements to implement it.