Princeton Meeting

I am often asked to explain how often compact binaries merge in the local universe; how often gravitational wave detectors will find the ripples in the fabric of the universe produced by these mergers; and what science these measurements enable.

Recent presentations of this kind include

January 2013, Princeton ; May, 2013, Caltech TAPIR group CGWAS 2013 summer school

The conservative answer involves only extrapolation from experience. We know pairs of neutron stars which will merge, in our galaxy; having lots of experience with finding neutron stars, we know how many exist in our galaxy, from what we’ve seen; and we know how galaxies similar to our own form stars in the nearby universe over the last few billion years. Combining these together, we find LIGO will almost certainly see the gravitational wave signal from merging NS-NS binaries.

The more aggressive answer involves substantial extrapolations away from known experience, using our best understanding of how compact binaries form. Compact binaries are known to form through binary evolution; “population synthesis” predictions involve using our best understanding of stellar evolution to generate synthetic binary populations. Compact binaries have also been observed in interacting stellar environments – globular clusters. Both by extrapolating from experience and using our best knowledge, these interacting environments could contribute many mergers…but probably don’t, based on our current expectations from the physics (e.g., Tsang et al 2013 review).

For more information, see

Abadie et al 2010, CQG 27 173001 Predictions for the rates of compact binary coalescences : A slightly dated review of the compact binary literature provided by my collaborators and I in LIGO. My work features prominently. J. Aasi et al, arxiv:1304.0760 Prospects for localization of gravitational wave transients Dominik et al 2012 ApJ 759 52 and arxiv:1308.1456 : The most recent results