Nonlinear memory in binary black hole waveforms

Denis Pollney

Although predominantly oscillatory, a complete gravitational wave signal also contains non-oscillatory components which result in secular drifts or offsets in the signals. Nonlinear gravitational memory arises from a change in mass multipole moments of a bound system due to contributions from the emitted gravitational waves. In practice it appears as a slowly monotonically growing signal during the inspiral which sees a rapid rise at the time of merger. The low amplitude and non-oscillatory nature of these signals present unique challenges for modeling. I discuss recent efforts to evaluate these signals in numerical simulations using characteristic extraction as well as their potential relevance to detection.