Special Colloquium:  (1.30pm, Physics 385)                                                                                                                                                                       

White Dwarf Supernovae: Physics and Cosmology       


Saurabh Jha (Rutgers University)          


Observations of type 1a supernovae (SN1a), 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, specifically the initial conditions and the explosion mechanism. I will show how our group at Rutgers uses data from the Southern African Large Telescope (SALT) and the Hubble Space Telescope (HST) to improve both our physical understanding of these cosmic explosions and their cosmological utility.