Comparing Merger and Ringdown Waveforms for Modified Gravity Theories

Binary black hole mergers are prime candidates when looking for deviations from GR in the strong-field regime. The parameterized post-Einsteinian (ppE) formalism provides a framework for constructing frequency domain GR waveforms into modified waveforms that account for leading PN order deviations predicted by a beyond-GR theory. These corrections are computed assuming a quasicircular inspiral, making the correction applicable only in the inspiral regime. We extend the ppE correction into the merger and ringdown regimes where beyond-GR corrections may also be expected. We compare theories which predict stronger corrections in the early inspiral against theories the predict corrections at merger, and these effects on parameter estimation.