Applying symplectic geometry to understand and refine Hamiltonian MC.
Parametrizing deviations from purely GR, vacuum black holes.
The deformation to spherically symmetric black holes under a class of corrections to general relativity.
Computing how much energy and momentum gravitational waves carry in a very broad class of almost-GR theories.
Turning an O(n^2) problem into an O(n log n) problem in radio interferometry, similar in spirit to how the fast Fourier transform operates.