Signatures of Planck corrections in a spiralling axion inflation model
Abstract
The minimal subPlanckian axion inflation model accounts for a large scalartotensor ratio via a spiralling trajectory in the field space of a complex field Φ. Here we consider how the predictions of the model are modified by Planck scalesuppressed corrections. In the absence of Planck corrections the model is equivalent to a ϕ{sup 4/3} chaotic inflation model. Planck corrections become important when the dimensionless coupling ξ of Φ{sup 2} to the topological charge density of the stronglycoupled gauge sector FF{sup ~} satisfies ξ∼1. For values of Φ which allow the Planck corrections to be understood via an expansion in powers of Φ{sup 2}/M{sub Pl}{sup 2}, we show that their effect is to produce a significant modification of the tensortoscalar ratio from its ϕ{sup 4/3} chaotic inflation value without strongly modifying the spectral index. In addition, to leading order in Φ{sup 2}/M{sub Pl}{sup 2}, the Planck modifications of n{sub s} and r satisfy a consistency relation, Δn{sub s}=−Δr/16. Observation of these modifications and their correlation would allow the model to be distinguished from a simple ϕ{sup 4/3} chaotic inflation model and would also provide a signature for the influence of leadingorder Planck corrections.
 Authors:
 Dept. of Physics, University of Lancaster,Lancaster LA1 4YB (United Kingdom)
 Publication Date:
 Sponsoring Org.:
 SCOAP3, CERN, Geneva (Switzerland)
 OSTI Identifier:
 22454547
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 05; Other Information: PUBLISHERID: JCAP05(2015)014; OAI: oai:repo.scoap3.org:10223; Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AXIONS; CHAOS THEORY; CHARGE DENSITY; CORRECTIONS; COSMOLOGICAL INFLATION; GAUGE INVARIANCE; SCALARS; STRONGCOUPLING MODEL; TENSORS; TOPOLOGY
Citation Formats
McDonald, John. Signatures of Planck corrections in a spiralling axion inflation model. United States: N. p., 2015.
Web. doi:10.1088/14757516/2015/05/014.
McDonald, John. Signatures of Planck corrections in a spiralling axion inflation model. United States. doi:10.1088/14757516/2015/05/014.
McDonald, John. 2015.
"Signatures of Planck corrections in a spiralling axion inflation model". United States.
doi:10.1088/14757516/2015/05/014.
@article{osti_22454547,
title = {Signatures of Planck corrections in a spiralling axion inflation model},
author = {McDonald, John},
abstractNote = {The minimal subPlanckian axion inflation model accounts for a large scalartotensor ratio via a spiralling trajectory in the field space of a complex field Φ. Here we consider how the predictions of the model are modified by Planck scalesuppressed corrections. In the absence of Planck corrections the model is equivalent to a ϕ{sup 4/3} chaotic inflation model. Planck corrections become important when the dimensionless coupling ξ of Φ{sup 2} to the topological charge density of the stronglycoupled gauge sector FF{sup ~} satisfies ξ∼1. For values of Φ which allow the Planck corrections to be understood via an expansion in powers of Φ{sup 2}/M{sub Pl}{sup 2}, we show that their effect is to produce a significant modification of the tensortoscalar ratio from its ϕ{sup 4/3} chaotic inflation value without strongly modifying the spectral index. In addition, to leading order in Φ{sup 2}/M{sub Pl}{sup 2}, the Planck modifications of n{sub s} and r satisfy a consistency relation, Δn{sub s}=−Δr/16. Observation of these modifications and their correlation would allow the model to be distinguished from a simple ϕ{sup 4/3} chaotic inflation model and would also provide a signature for the influence of leadingorder Planck corrections.},
doi = {10.1088/14757516/2015/05/014},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 05,
volume = 2015,
place = {United States},
year = 2015,
month = 5
}

The minimal subPlanckian axion inflation model accounts for a large scalartotensor ratio via a spiralling trajectory in the field space of a complex field Φ. Here we consider how the predictions of the model are modified by Planck scalesuppressed corrections. In the absence of Planck corrections the model is equivalent to a φ{sup 4/3} chaotic inflation model. Planck corrections become important when the dimensionless coupling ξ of Φ{sup 2} to the topological charge density of the stronglycoupled gauge sector F Ftilde satisfies ξ ∼ 1. For values of Φ which allow the Planck corrections to be understood via an expansion in powersmore »

Planckscale corrections to axion models
It has been argued that quantum gravitational effects will violate all nonlocal symmetries. PecceiQuinn symmetries must therefore be an accidental'' or automatic consequence of local gauge symmetry. Moreover, higherdimensional operators suppressed by powers of {ital M}{sub Pl} are expected to explicitly violate the PecceiQuinn symmetry. Unless these operators are of dimension {ital d}{ge}10, axion models do not solve the strong {ital CP} problem in a natural fashion. A small gravitationally induced contribution to the axion mass has little if any effect on the density of relic axions. If {ital d}=10, 11, or 12 these operators can solve the axion domainwallmore » 
A minimal subPlanckian axion inflation model with large tensortoscalar ratio
We present a minimal axion inflation model which can generate a large tensortoscalar ratio while remaining subPlanckian. The modulus of a complex scalar field Φ with a λΦ{sup 4} potential couples directly to the gauge field of a stronglycoupled sector via a term of the form (Φ/M{sub Pl}){sup m}F Ftilde . This generates a minimum of the potential which is aperiodic in the phase. The resulting inflation model is equivalent to a φ{sup 4/(m+1)} chaotic inflation model. For the natural case of a leadingorder portallike interaction of the form Φ{sup †}ΦF Ftilde , the model is equivalent to a φ{supmore » 
New model of axion monodromy inflation and its cosmological implications
We propose a new realization of axion monodromy inflation in which axion monodromy arises from torsional cycles in a type IIB compactification. A class of monomial potentials is obtained with specific values for the power index. Moreover, the inflaton mass changes profile due to the couplings between various fields after compactification. Consequently, the potential obtains a steplike profile at some critical scale. We study the cosmological implications of one concrete realization of this model. At the background level, it realizes a sufficiently long inflationary stage, which allows for the violation of the slowroll conditions for a short period of timemore »