Oscillating Chiral Tensor Spectrum from Axionic Inflation

Abstract

We study the axionic inflation with a modulated potential and examine if the primordial tensor power spectrum exhibits oscillatory feature, which is testable with future space-based gravitational wave experiments such as DECIGO and BBO. In the case of the single-field axion monodromy inflation, it turns out that it is difficult to detect the oscillation in the spectrum due to suppression of the sub-Planckian decay constant of axion. On the other hand, in the case of aligned chromo-natural inflation where the axion is coupled to a SU(2) gauge field, it turns out that the sizable oscillation in the tensor spectrum can occur due to the enhancement of chiral gravitational waves sourced by the gauge field. We expect that this feature will be a new probe to axion phenomenologies in early universe through the chiral gravitational waves.

References in corpus (6)

• Monodromy in the CMB: Gravity Waves and String Inflation
• Generation and Characterization of Large Non-Gaussianities in Single Field Inflation
• The Powers of Monodromy
• Natural Inflation and Quantum Gravity
• Oscillating modulation to B-mode polarization from varying propagating speed of primordial gravitational waves
• Axion monodromy inflation with sinusoidal corrections

Cited by in corpus (4)

• Gravitational waves at interferometer scales and primordial black holes in axion inflation
• Higgsed Chromo-Natural Inflation
• Chirality oscillation of primordial gravitational waves during inflation
• Generation of gravitational waves from symmetry restoration during inflation