Resolving Gravitational Memory in Numerical Relativity using Cauchy-characteristic Extraction

Although gravitational memory was realized in the 1970s, numerical simulations of binary black hole mergers have been unable to resolve this phenomenon until now. We show that by using Cauchy-characteristic extraction (CCE) to extract waveforms in simulations produced by SXS's Spectral Einstein Code, we can accurately resolve the gravitational memory. We present results for memory in simulations with a variety of mass ratios and spins. We also discuss the measurability of memory for both LIGO and LISA.