Probing polarization states of primordial gravitational waves with cosmic microwave background anisotropies
Probing polarization states of primordial gravitational waves with cosmic microwave background anisotropies
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yields parity violating terms, which may produce a circularly polarized gravitational wave background (GWB) during inflation. In contrast to the standard prediction of inflation …