15th Capra Meeting on Radiation Reaction in General Relativity

Green functions, caustics, and self-force

Abraham Harte

Albert Einstein Institute
[SLIDES]

Green functions are discussed in spacetimes where light cones can develop caustics. The leading order singular structure of a field disturbance is found to follow a simple rule near null geodesics. This is derived by showing that part of the structure of a generic Green function can be extracted from a Green function on an appropriate plane wave spacetime. The influence of caustics on self-force is briefly discussed