We introduce a new geometrically invariant prescription for comparing two different spacetimes based on geodesic deviation. We use this method to compare a family of recently introduced analytical spacetime representing inspiraling black-hole binaries to fully nonlinear numerical solutions to the Einstein equations. Our method can be used to improve analytical spacetime models by providing a local measure of the effects that violations of the Einstein equations will have on timelike geodesics, and indirectly, gas dynamics. We also discuss the advantages and limitations of this method.
@article{arxiv.1802.02990,
title = {Comparing an analytical spacetime metric for a merging binary to a fully nonlinear numerical evolution using curvature scalars},
author = {Jam Sadiq and Yosef Zlochower and Hiroyuki Nakano},
journal= {arXiv preprint arXiv:1802.02990},
year = {2018}
}