Astronomy Journal Club: Ben Ryan - Confirming the Kerr Metric for Dark Compact Objects
Speaker Ben Ryan
Date Dec 7, 2012
Time 12:00 pm
Location 134 Astronomy Building
Sponsor Department of Astronomy
Event type Pizza lunch
Analytic solutions to the Einstein field equations for a point particle possessing mass, angular momentum, and electric charge are widely assumed to provide an exact representation for astrophysical 'black holes.' These objects are inferred from measurements of the electromagnetic spectrum of associated accretion disks and kinematic observations of nearby luminous objects which indicate large amounts of mass contained within a few Schwarzschild radii.
Such objects are unique for the assumed simplicity with which they can be completely parametrized given the scale of the entropy they possess, and are impossible to observe directly. The implication, therefore, is that one must be careful in relying on the canonical model of these objects, particularly in light of the possibility of general relativity being supplanted by an alternative theory of gravity.
The observational evidence for compact objects distinct from more traditional dense matter is reviewed as context, and tests of the Kerr metric as a model for these objects are discussed.