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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
| Article number | 014 |
|---|---|
| <mark>Journal publication date</mark> | 8/05/2015 |
| <mark>Journal</mark> | Journal of Cosmology and Astroparticle Physics |
| Issue number | 5 |
| Number of pages | 13 |
| Publication Status | Published |
| <mark>Original language</mark> | English |
The minimal sub-Planckian axion inflation model accounts for a large scalar-to-tensor ratio via a spiralling trajectory in the field space of a complex field Phi. Here we consider how the predictions of the model are modified by Planck scale-suppressed corrections. In the absence of Planck corrections the model is equivalent to a phi(4/3) chaotic inflation model. Planck corrections become important when the dimensionless coupling xi of |Phi|(2) to the topological charge density of the strongly-coupled gauge sector F (F) over tilde satisfies xi similar to 1. For values of |Phi| which allow the Planck corrections to be understood via an expansion in powers of |Phi|(2)/M-P1(2), we show that their effect is to produce a significant modification of the tensor-to-scalar ratio from its phi(4/3) chaotic inflation value without strongly modifying the spectral index. In addition, to leading order in |Phi|(2)/M-P1(2), the Planck modifications of n(s) and r satisfy a consistency relation, Delta n(s) = -Delta r/16. Observation of these modifications and their correlation would allow the model to be distinguished from a simple phi(4/3) chaotic inflation model and would also provide a signature for the influence of leading-order Planck corrections.