1301.2598 (Peter Adshead et al.)

A Sinister Universe: Chiral gravitons lurking, and Lyth un-bound    [PDF]

Peter Adshead, Emil Martinec, Mark Wyman

Models of inflation involving non-Abelian gauge field backgrounds can produce gravitational waves at an observable level with a preferred handedness, while satisfying current observational bounds. This asymmetry comes about because the non-Abelian background generates parity-violation in the action for perturbations. In the specific model we study, Chromo-Natural Inflation, these gravitational waves can be produced at observable levels even when no field makes a super-Planckian field excursion, thus evading a common formulation of the Lyth bound.

View original: http://arxiv.org/abs/1301.2598