Generic features of Einstein-Aether black holes

We reconsider spherically symmetric black hole solutions in Einstein-Aether theory with the condition that this theory has identical parametrized post-Newtonian parameters as those for general relativity, which is the main difference from the previous research. In contrast with previous study, we allow superluminal propagation of a spin-0 Aether-gravity wave mode. As a result, we obtain black holes having a spin-0 horizon inside an event horizon. We allow a singularity at a spin-0 horizon since it is concealed by the event horizon. If we allow such a configuration, the kinetic term of the Aether field can be large enough for black holes to be significantly different from Schwarzschild black holes with respect to Arnowitt-Deser-Misner mass, innermost stable circular orbit, Hawking temperature, and so on. We also discuss whether or not the above features can be seen in more generic vector-tensor theories.