Chiral primordial gravitational waves from a Lifshitz point.
We study primordial gravitational waves produced during inflation in quantum gravity at a Lifshitz point proposed by Horava. Assuming power-counting renormalizability, foliation-preserving diffeomorphism invariance, and the condition of detailed balance, we show that primordial gravitational waves are circularly polarized due to parity violation. The chirality of primordial gravitational waves is a quite robust prediction of quantum gravity at a Lifshitz point which can be tested through observations of cosmic microwave background radiation and stochastic gravitational waves.
Takahashi
Tomohiro
T
Department of Physics, Kyoto University, Kyoto, 606-8501, Japan.
Soda
Jiro
J