New Directions in Gravity Searches for Spacetime-Symmetry breaking

In this talk, we review recent results in testing spacetime symmetries in gravitational physics. Topics discussed include new signals for hypothetical Lorentz and diffeomorphism symmetry violations in short-range gravity tests. We review results for multipole expansions that predict extra polarizations for gravitational waves. Both explicit and spontaneous spacetime-symmetry breaking origins are considered. We also discuss recent numerical results for black hole solutions in a vector field model of spontaneous symmetry breaking.