March 26 , 2007

Testing the Kerr Metric: Confronting strong field relativity with
observations

Avery E. Broderick

General Relativity has been remarkably successful, passing every test that it has been put to.  However, we are only beginning to test GR in the strong field limit, primarily with the aid of black holes and neutron stars.  I will discuss how observations of the supermassive black hole at the Galactic center may be used to test qualitative predictions of GR (e.g., the existence of black hole horizons) as well as provide a quantitative test of the Kerr metric specifically. Critical to these efforts will be the development of a sub-millimeter Very Long Baseline Array, which could be done in the next five years at minimal cost, and polarization observations, which are already being done.