The SpECTRE Cauchy-characteristic evolution system for rapid, precise waveform extraction

We give full details regarding the new Cauchy-characteristic evolution (CCE)system in SpECTRE. The implementation is built to provide streamlinedflexibility for either extracting waveforms during the process of a SpECTREbinary compact object simulation, or as a standalone module for extractingwaveforms from worldtube data provided by another code base. Using our recentlypresented improved analytic formulation, the CCE system is free of pure-gaugelogarithms that would spoil the spectral convergence of the scheme. Itgracefully extracts all five Weyl scalars, in addition to the news and thestrain. The SpECTRE CCE system makes significant improvements on previousimplementations in modularity, ease of use, and speed of computation.