Improving SEOBNRv3 for LIGO Parameter Estimation

The Spinning Effective One Body--Numerical Relativity (SEOBNR) series of gravitational wave approximants are among the best available for Advanced LIGO/Virgo parameter estimation (PE). Over the past two years we have sped up, via direct code optimization, the eight-dimensional SEOBNR version 3 (SEOBNRv3) approximant by a factor of ~340x. This is particularly significant since there is no known way to develop an efficient eight-dimensional Reduced-Order Model that is faster than the SEOB code itself. We report on our latest work, both in speeding up our optimized SEOBNRv3 approximant (SEOBNRv3_opt) by another order of magnitude and in making SEOBNRv3_opt more robust than SEOBNRv3. This work brings direct SEOBNRv3-based PE within reach for many important LIGO sources.