Generic features of Einstein-Aether black holes

Black Holes in Einstein-Aether Theory

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 spin-0, spin1, and spin-2 modes whose speeds depend on four coupling coefficients. We find that the full three-parameter family of local spherically symm...

Engineering Einstein: Astrophysical Black Holes

Einstein-aether Theory *

Could there be an æther after all and we have just not yet noticed it? By an “æther” of course we do not mean to suggest a mechanical medium whose deformations correspond to electromagnetic fields, but rather a locally preferred state of rest at each point of spacetime, determined by some hitherto unknown physics. Such a frame would not be determined by a circumstance such as the moon’s gravita...

Stability of higher derivative modifications of Einstein - aether theory

A time-like unit vector field is used to generalize Einstein's gravity. The resulting theory, called the Einstein-aether theory, consists of a minimal coupling between an aether field and gravity. Inspired by the Bopp-Podolsky electrodynamics, which is well-known for removing the singularity at the point charge, we generalized the Einstein-aether theory by adding such a higher order self-intera...

Observational Features of Black Holes

Recently Holz & Wheeler [59] considered a very attracting possibility to detect retro-MACHOs, i.e. retroimages of the Sun by a Schwarzschild black hole. In this paper we discuss glories (mirages) formed near rapidly rotating Kerr black hole horizons and propose a procedure to measure masses and rotation parameters analyzing these forms of mirages. In some sense that is a manifestation of gravit...