Polarizing primordial gravitational waves by parity violation

We study primordial gravitational waves in the Horava-Lifshitz theory of quantum gravity, in which high-order spatial derivative operators, including the ones violating parity, generically appear in order for the theory to be power-counting renormalizable and ultraviolet complete. Because of both parity violation and the nonadiabatic evolution of the modes due to a modified dispersion relationship, a large polarization of primordial gravitational waves becomes possible, and it could be well within the range of detection of the BB, TB and EB power spectra of the forthcoming cosmic microwave background observation, where T, E, and B stand, respectively, the different components of the polarization of the cosmic microwave background radiation.