Saul A. Teukolsky

Relativistic plasmas around compact objects can sometimes be approximated as being force-free. In this limit, the plasma inertia is negligible and the overall dynamics is governed by global electric currents. We present a novel numerical approach for simulating such force-free plasmas, which allows for high accuracy in smooth regions as well as capturing dissipation in current sheets.

Abstract We give full details regarding the new Cauchy-characteristic evolution (CCE) system in spectre. The implementation is built to provide streamlined flexibility for either extracting waveforms during the process of a spectre binary compact object simulation or as a stand-alone module for extracting waveforms from worldtube data provided by another code base.

Abstract The parametrized post-Einsteinian framework modifies inspiral waveform models to incorporate effects beyond general relativity (GR). We extend the existing model into the merger-ringdown regime. The modification introduced here adds a single degree of freedom that corresponds to a change in the binary coalescence time. Other merger properties remain as predicted by GR. We discuss parameter estimation with this model, and how it can be used to extract information from beyond-GR waveforms.