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 } = 36 ^ { +5 } _ { -4 } M _ { \odot } and m _ { 2 } = 29 ^ { +4 } _ { -4 } M _ { \odot } , 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 _ { \odot } and m _ { 2 } = 35 M _ { \odot } , and strong anti-aligned spins ( \chi _ { 1 } = 0.95 and \chi _ { 2 } = -0.95 ) yield almost the same signal-to-noise ratio in the strain data for GW150914 .