Cosmic Polarization Rotation, Cosmological Models, and the Detectability of Primordial Gravitational Waves

Understand

CMB (Cosmic Microwave Background) polarization observations test many aspects of cosmological models.

• Effective pseudoscalar-photon interaction(s) would induce a rotation of linear polarization of electromagnetic wave propagating with cosmological distance in various cosmological models.
• CMB polarization observations are superb tests of these models and have the potential to discover new fundamental physics.
• Pseudoscalar-photon interaction is proportional to the gradient of the pseudoscalar field.