TY - JOUR

T1 - Hypernatural inflation

AU - Linde, Andrei

AU - Wang, Dong Gang

AU - Welling, Yvette

AU - Yamada, Yusuke

AU - Achúcarro, Ana

N1 - Funding Information:
We thank Renata Kallosh, Diederik Roest and Alexander Westphal for stimulating discussions and collaborations on related work. The work of AL and YY is supported by SITP and by the US National Science Foundation grant PHY-1720397. DGW and YW are supported by a de Sitter Fellowship of the Netherlands Organization for Scientific Research (NWO). The work of AA is partially supported by the Netherlands’ Organization for Fundamental Research in Matter (FOM), by the Basque Government (IT-979-16) and by the Spanish Ministry MINECO (FPA2015-64041-C2-1P).
Publisher Copyright:
© 2018 IOP Publishing Ltd and Sissa Medialab.

PY - 2018/7/16

Y1 - 2018/7/16

N2 - We construct a model of natural inflation in the context of α-attractor supergravity, in which both the dilaton field and the axion field are light during inflation, and the inflaton may be a combination of the two. The T-model version of this theory is defined on the Poincaré disk with radius |Z| = 1. It describes a Mexican hat potential with the flat axion direction corresponding to a circle of radius |Z| < 1. The axion decay constant fa in this theory can be exponentially large because of the hyperbolic geometry of the Poincaré disk. Depending on initial conditions, this model may describe α-attractor inflation driven by the radial component of the inflaton field, natural inflation driven by the axion field, or a sequence of these two regimes. We also construct the E-model version of this theory, which have similar properties. In addition, we describe generalized α-attractor models where the potential can be singular at the boundary of the moduli space, and show that they can provide a simple solution for the problem of initial conditions for the models with plateau potentials.

AB - We construct a model of natural inflation in the context of α-attractor supergravity, in which both the dilaton field and the axion field are light during inflation, and the inflaton may be a combination of the two. The T-model version of this theory is defined on the Poincaré disk with radius |Z| = 1. It describes a Mexican hat potential with the flat axion direction corresponding to a circle of radius |Z| < 1. The axion decay constant fa in this theory can be exponentially large because of the hyperbolic geometry of the Poincaré disk. Depending on initial conditions, this model may describe α-attractor inflation driven by the radial component of the inflaton field, natural inflation driven by the axion field, or a sequence of these two regimes. We also construct the E-model version of this theory, which have similar properties. In addition, we describe generalized α-attractor models where the potential can be singular at the boundary of the moduli space, and show that they can provide a simple solution for the problem of initial conditions for the models with plateau potentials.

KW - Inflation

KW - supersymmetry and cosmology

UR - http://www.scopus.com/inward/record.url?scp=85051750268&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051750268&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2018/07/035

DO - 10.1088/1475-7516/2018/07/035

M3 - Article

AN - SCOPUS:85051750268

VL - 2018

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 7

M1 - 035

ER -