The critical issue in cosmology today lies in understanding the unidentified ingredient in the cosmic energy budget that acts against the gravitational attraction of normal matter making up the stars and galaxies, leading to an expanding Universe that is speeding up. With our current best guess of this ” energy“, namely Einstein’s cosmological constant, at odds with our particle physics predictions, we are tasked with finding an alternative theory. However, our profound lack of intuition of the physics behind energyplaces severe constraints on our ability to make progress, forcing us to make assumptions about the time evolution of energy as well as the other cosmological parameters that could, if incorrect, render our results meaningless. In this talk, I will present 3 approaches which can accurately determine if and how energy changes with time with no prior assumptions about it. I will show that using the data expected from the future-generation SuperNovae Acceleration Probe (SNAP) experiment, we will be able to determine the correct model of energy even if it is beyond the scope of our current theories.
Astrophysics and Cosmology Research Unit, School of Chemistry and Physics, University of Kwazulu-Natal