Consistency of the canonical formulation of Horava Gravity

Chopin Soo

Both the projectable and non-projectable formulation of Horava gravity face serious challenges. In the latter, with spacetime dependent lapse function, the local Hamiltonian constraint gives rise to inconsistencies in the constraint algebra (as was pointed out by Henneaux and coworkers). On the other hand, the projectable version, with spatially independent lapse function and global Hamiltonian constraint, produces a first class constrained system; but the absence of a local constraint results in an extra scalar graviton mode which poses serious phemenological difficulties. An alternative canonical formulation of Horava gravity will be presented. It resolves the difficulties by producing both a consistent set of first class constraints and also equivalently enforcing a local Hamiltonian constraint which eliminates the spurious graviton mode.