# Chiral Photons from Chiral Gravitational Waves.

@article{Inomata2019ChiralPF, title={Chiral Photons from Chiral Gravitational Waves.}, author={Keisuke Inomata and M. Kamionkowski}, journal={Physical review letters}, year={2019}, volume={123 3}, pages={ 031305 } }

We show that a parity-breaking uniform (averaged over all directions on the sky) circular polarization of amplitude V_{00}≃2.6×10^{-17}Δχ(r/0.06) can be induced by a chiral gravitational-wave (GW) background with a tensor-to-scalar ratio r and chirality parameter Δχ (which is ±1 for a maximally chiral background). We also show, however, that a uniform circular polarization can arise from a realization of a nonchiral GW background that spontaneously breaks parity. The magnitude of this… Expand

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