Horava-Lifshitz theory as a Fermionic Aether in Ashtekar gravity
  We show how Ho\v{r}ava-Lifshitz (HL) theory appears naturally in the Ashtekar
formulation of relativity if one postulates the existence of a fermionic field
playing the role of aether. The spatial currents associated with this field
must be switched off for the equivalence to work. Therefore the field supplies
the preferred frame associated with breaking refoliation (time diffeomorphism)
invariance, but obviously the symmetry is only spontaneously broken if the
field is dynamic. When Dirac fermions couple to the gravitational field via the
Ashtekar variables, the low energy limit of HL gravity, recast in the language
of Ashtekar variables, naturally emerges (provided the spatial fermion current
identically vanishes). HL gravity can therefore be interpreted as a time-like
current, or a Fermi aether, that fills space-time, with the Immirzi parameter,
a chiral fermionic coupling, and the fermionic charge density fixing the value
of the parameter $\lambda$ determining HL theory. This reinterpretation sheds
light on some features of HL theory, namely its good convergence properties.
