Related papers: Completing Natural Inflation
An axion-like inflaton coupled to non-Abelian gauge bosons provides a compelling microphysical framework for warm inflation. Starting even from cold initial conditions, in these systems, sphaleron heating may generate thermal friction…
A generic non-minimal coupling can push any higher-order terms of the scalar potential sufficiently far out in field space to yield observationally viable plateau inflation. We provide analytic and numerical evidence that this generically…
In the context of single field inflation, models with a quadratic potential and models with a natural potential with subplanckian decay constant are in tension with the Planck data. We show that, when embedded in a two-field model with an…
We propose a novel scenario in which scalar perturbations, that seed the large scale structure of the Universe, are generated without relying on a scalar field (the inflaton). In this framework, inflation is driven by a de Sitter space-time…
We present a toy model of an axion gauge field inflation scenario that yields viable density and gravitational wave spectra. The scenario consists of an axionic inflaton in a steep potential that is effectively flattened by a coupling to a…
The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest…
We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly…
Models of chaotic inflation with a fractional power-law potential are not only viable but also testable in the foreseeable future. We show that such models can be realized in simple strongly coupled supersymmetric gauge theories. In these…
Within General Relativity, a minimally coupled scalar field governed by a quadratic potential is able to produce an accelerated expansion of the universe provided its value and excursion are larger than the Planck scale. This is an…
We focus on the massive gauge theory formulation of axion monodromy inflation. We argue that a gauge symmetry hidden in these models is the key protection mechanism from dangerous corrections from both field theory and gravitational…
Recently it was shown that discrete R-invariance in superpotential can lead to a successful flat potential in inflation. We suggest that this discrete R-symmetry arises from an underlying supersymmetric gauge theory, which gives rise to a…
We describe a novel technique that renders theories of $N$ axions tractable, and more generally can be used to efficiently analyze a large class of periodic potentials of arbitrary dimension. Such potentials are complex energy landscapes…
We examine the theoretical possibility for the heavy QCD axion to induce slow-roll inflation while solving the strong CP problem through the Peccei-Quinn mechanism. If the cancellation between contributions from a small-size instanton and…
We propose a scenario for realizing super-Planckian axion decay constants in Calabi-Yau orientifolds of type IIB string theory, leading to large-field inflation. Our construction is a simple embedding in string theory of the mechanism of…
Axions play a central role in many realizations of large field models of inflation and in recent alternative mechanisms for generating primordial tensor modes in small field models. If these axions couple to gauge fields, the coupling…
Large field inflation can be sensitive to perturbative and nonperturbative quantum corrections that spoil slow roll. A large number $N$ of light species in the theory, which occur in many string constructions, can amplify these problems.…
A consistent non-compact axion cosmology requires a non-periodic field, an effective field theory valid sufficiently above the inflationary scale, and a small non-QCD contribution to the potential that tilts the axionic vacuum landscape in…
The possibility of having an inflationary epoch within a noncommutative geometry approach to unifying gravity and the standard model is demonstrated. This inflationary phase occurs without the need to introduce "ad hoc" additional fields or…
In this note we show that models of natural inflation based on closed string axions are incompatible with the weak gravity conjecture (WGC). Specifically, we use T-duality in order to map the bounds on the charge-to-mass ratio of particles…
Considering the conformal scaling gauge symmetry as a fundamental symmetry of nature in the presence of gravity, a scalar field is required and used to describe the scale behavior of universe. In order for the scalar field to be a physical…