
Physics 2006
Black Holes in EinsteinAether TheoryDOI: 10.1088/02649381/27/4/049802 Abstract: We study black hole solutions in general relativity coupled to a unit timelike vector field dubbed the "aether". To be causally isolated a black hole interior must trap matter fields as well as all aether and metric modes. The theory possesses spin0, spin1, and spin2 modes whose speeds depend on four coupling coefficients. We find that the full threeparameter family of local spherically symmetric static solutions is always regular at a metric horizon, but only a twoparameter subset is regular at a spin0 horizon. Asymptotic flatness imposes another condition, leaving a oneparameter family of regular black holes. These solutions are compared to the Schwarzschild solution using numerical integration for a special class of coupling coefficients. They are very close to Schwarzschild outside the horizon for a wide range of couplings, and have a spacelike singularity inside, but differ inside quantitatively. Some quantities constructed from the metric and aether oscillate in the interior as the singularity is approached. The aether is at rest at spatial infinity and flows into the black hole, but differs significantly from the the 4velocity of freelyfalling geodesics.
