Institute for Advanced Study Informal Astrophysics Seminar

ABSTRACT: Type Ia supernovae (SN Ia) are exquisite tools with which to trace the history of cosmic expansion, and they have a starring role in attempts to understand the dark energy that drives our accelerating Universe. Current supernova samples have grown to a size where systematic uncertainties are beginning to dominate statistical ones. I will describe the factors that limit the precision of our cosmological inferences and avenues for improvement, with a focus on understanding the reddening of SN Ia (by dust or otherwise) and constraining SN Ia progenitor models through observations of peculiar objects. I will also discuss new applications of precise distances from SN Ia in current and upcoming surveys.