Observations of type Ia supernovae (SN Ia), a class of exploding stars,
ushered in a cosmological revolution: the expansion of the Universe is
accelerating, driven by dark energy. I will describe how we are using these
exploding white dwarf stars to study the expansion history of the Universe,
and the prospects for precision cosmology with future supernova surveys
through flagship projects like the Large Synoptic Survey Telescope (LSST) on
the ground and the Wide-Field Infrared Survey Telescope (WFIRST) in space.
Surprisingly, one of the major uncertainties in this field is linked to our
lack of detailed understanding of the physics of these supernovae. Unusual
objects, including a class we call "type-Iax" supernovae, provide a window
into the progenitors, binary companions, and explosion mechanisms of white
dwarf supernovae, and may yield imporant clues to the nature of SN Ia and the
variety of systems that result in white dwarf explosions.
[Host: Rahman Amanullah]