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Caltech

TAPIR Seminar

Friday, May 17, 2013
2:00pm to 3:00pm
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Cahill 370
Fast evaluation of asymptotic waveforms from gravitational perturbations
Scott Field, Postdoctoral Fellow, Joint Space-Science Institute, University of Maryland,

In the context of blackhole perturbation theory, I describe evaluation of an asymptotic waveform from data (Regge-Wheeler-Zerilli master functions given as a time-series) recorded at a radial location. The asymptotic waveform is represented as a convolution of the data with a time-domain kernel comprised of a few damped exponentials. In turn, each exponential's strength and damping rate arises from a sum-of-poles approximation of a Laplace frequency domain kernel. I will motivate the origin of the frequency domain kernel as well as the numerical techniques needed for its sum-of-poles approximation. The method is used to study late-time decay tails at null-infinity, "teleportation" of a signal between two finite radial values, and luminosities from extreme-mass-ratio binaries. Through numerical simulations with data recorded as close as r = 30M, I compute asymptotic waveforms with late-time -4 decay (for l = 2 perturbations), and also luminosities from circular and eccentric orbits that match frequency domain results to relative errors of better than 10^{-9}. These results are achieved without a compactification scheme, extrapolation procedure or even solving a PDE.

For more information, please contact JoAnn Boyd by phone at 4280 or by email at [email protected].