n-DBI gravity, maximal slicing and the Kerr geometry

Abstract: Recently, in arXiv:1110.0832, we have established that solutions of Einstein's gravity admitting foliations with a certain geometric condition are also solutions of n-DBI gravity, arXiv:1109.1468. Here we observe that, in vacuum, the required geometric condition is fulfilled by the well known maximal slicing, often used in numerical relativity. As a corollary, we establish that the Kerr geometry is a solution of n-DBI gravity in the foliation adapted to Boyer-Lindquist coordinates.