Degeneracy of gravitational waveforms in the context of GW150914

James Creswell; Hao Liu; Andrew D. Jackson; Sebastian von Hausegger; Pavel Naselsky

doi:10.1088/1475-7516/2018/03/007

paper

Degeneracy of gravitational waveforms in the context of GW150914

arXiv:1803.02350 · doi:10.1088/1475-7516/2018/03/007

Abstract

We study the degeneracy of theoretical gravitational waveforms for binary black hole mergers using an aligned-spin effective-one-body model. After appropriate truncation, bandpassing, and matching, we identify regions in the mass--spin parameter space containing waveforms similar to the template proposed for GW150914, with masses $m_{1} = 3 6_{- 4}^{+ 5} M_{⊙}$ and $m_{2} = 2 9_{- 4}^{+ 4} M_{⊙}$ , using the cross-correlation coefficient as a measure of the similarity between waveforms. Remarkably high cross-correlations are found across broad regions of parameter space. The associated uncertanties exceed these from LIGO's Bayesian analysis considerably. We have shown that waveforms with greatly increased masses, such as $m_{1} = 70 M_{⊙}$ and $m_{2} = 35 M_{⊙}$ , and strong anti-aligned spins ( $χ_{1} = 0.95$ and $χ_{2} = - 0.95$ ) yield almost the same signal-to-noise ratio in the strain data for GW150914.

Accepted for publication in JCAP