IPAC Colloquia --:Yun Wang (Univ. of Oklahoma) -- Probing the Nature of Cosmic Acceleration

The cause for the observed acceleration in the expansion of the universe is unknown, and referred to as "dark energy" for convenience. Dark energy could be an unknown energy component, or a modification of Einstein's general relativity. This determines the measurements that are optimal in unveiling the nature of dark energy: the cosmic expansion history, and the growth history of cosmic large scale structure. I will examine galaxy clustering and Type Ia supernovae as dark energy probes, and discuss recent results and future prospects.