Gravity seminar - Jonathan Thornburg Seminar

 

I will begin with a brief overview of extreme mass-ratio black hole binaries (EMRIs), why they're interesting systems to study, and why it's hard to model their radiation-reaction dynamics to the desired accuracy. I will then outline one particular approach to this modelling using a puncture-function regularization of the perturbation equations, and present numerical results for a toy model: a scalar-field particle in an equatorial eccentric orbit in Kerr spacetime. For certain orbits the radiation-raction force acting on the particle exhibits large "wiggles" after each periastron passage. These appear to be due to the excitation of Kerr quasi-normal modes (QNMs) by the particle, followed by a later encounter of the particle with field radiated from the QNMs.