  We show that there is a minimal Einstein-Aether theory, obtained as a
phenomenologically and theoretically consistent limit from the generic
Einstein-Aether theory, that supports Einstein metrics as solutions with a
reduced cosmological constant. The minimal theory is obtained by taking three
of the coupling constants to be zero but keeping the expansion coupling
constant to be nonzero. The square of the expansion of the unit-timelike aether
field depletes the bare cosmological constant and thus provides, via local
Lorentz symmetry breaking inherent in the Einstein-Aether theories, a novel
mechanism for reconciling the observed, small cosmological constant (or dark
energy) with the large theoretical prediction coming from quantum field
theories. The crucial point here is that minimal Einstein-Aether theory does
not modify the well-tested aspects of General Relativity such as solar systems
tests and black hole physics including gravitational waves.
