While general relativity possesses local Lorentz invariance, both canonical
quantum gravity and string theory suggest that Lorentz invariance may be broken
at high energies. Broken Lorentz invariance has also been postulated as an
explanation for astrophysical anomalies such as the missing GZK cutoff.
Therefore, we seek an effective field theory description of gravity where
Lorentz invariance is broken. We will construct a candidate theory and then
briefly discuss some of the implications.
