Mapping apparent horizon centers in SpECTRE simulations of binary black holes with unequal masses

SpECTRE is a next-generation numerical-relativity code that uses a discontinuous-Galerkin method combined with task-based parallelism. As with the Spectral Einstein Code (SpEC), SpECTRE excises singularities from the computational domain and then deforms the spatial domain so that the boundaries of the excised region track the positions, shapes, and sizes of the black-hole horizons. In this talk, I will discuss an implementation of a map that tracks the horizon centers that combines translation, rotation, and expansion, and I will demonstrate the map in SpECTRE evolutions of binary black holes with unequal masses.