Testing supernova cosmology and progenitor effects with the SDSS-II supernova survey

The study of Type Ia Supernovae, the brilliant explosions of White Dwarfs, has ushered in a new era of observational Cosmology, one in which we have learned that the Universe is not only expanding, but accelerating in its expansion. For further advances to be made in the the field of Supernova Cosmology, future planned surveys will have to understand the systematic differences in these explosions. We use the full 3-year observational data from the Sloan Digital Sky Survey - II Supernova Survey to explore this field. First, we show that the environment a Type Ia Supernova occurs in biases the distance modulus at which current algorithms place them, resulting in a systematic error in derived cosmological parameters. We then investigate the ability Type II-P Supernovae to be used as complements to their brighter cousins as cosmological distance indicators, subject to different progenitor effects and thus different sources of uncertainty. Finally we quantify the diversity in Type II-P Supernovae themselves and the relationship the environment has on their observational properties, and the propensity this might have for biasing distance measurements with these objects