### Abstract

We investigate a constraint on reheating followed by α-attractor-type inflation (the E-model and T-model) from an observation of the spectral index ns. When the energy density of the Universe is dominated by an energy component with the cosmic equation-of-state parameter wre during reheating, its e-folding number Nre and the reheating temperature Tre are bounded depending on wre. When the reheating epoch consists of two phases - where the energy density of the Universe is dominated by uniform inflaton field oscillations in the first phase and by relativistic nonthermalized particles in the second phase - we find a constraint on the e-folding number of the first oscillation phase, Nsc, depending on the parameters of the inflaton potential. For the simplest perturbative reheating scenario, we find the lower bound for a coupling constant of inflaton decay in the E-model and T-model depending on the model parameters. We also find a constraint on the α parameter, α0.01, for the T-model and E-model when we assume a broad resonance reheating scenario.

Original language | English |
---|---|

Article number | 083524 |

Journal | Physical Review D |

Volume | 93 |

Issue number | 8 |

DOIs | |

Publication status | Published - Apr 28 2016 |

Externally published | Yes |

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### All Science Journal Classification (ASJC) codes

- Physics and Astronomy (miscellaneous)

### Cite this

*Physical Review D*,

*93*(8), [083524]. https://doi.org/10.1103/PhysRevD.93.083524

**Constraints on α -attractor inflation and reheating.** / Ueno, Yoshiki; Yamamoto, Kazuhiro.

Research output: Contribution to journal › Article

*Physical Review D*, vol. 93, no. 8, 083524. https://doi.org/10.1103/PhysRevD.93.083524

}

TY - JOUR

T1 - Constraints on α -attractor inflation and reheating

AU - Ueno, Yoshiki

AU - Yamamoto, Kazuhiro

PY - 2016/4/28

Y1 - 2016/4/28

N2 - We investigate a constraint on reheating followed by α-attractor-type inflation (the E-model and T-model) from an observation of the spectral index ns. When the energy density of the Universe is dominated by an energy component with the cosmic equation-of-state parameter wre during reheating, its e-folding number Nre and the reheating temperature Tre are bounded depending on wre. When the reheating epoch consists of two phases - where the energy density of the Universe is dominated by uniform inflaton field oscillations in the first phase and by relativistic nonthermalized particles in the second phase - we find a constraint on the e-folding number of the first oscillation phase, Nsc, depending on the parameters of the inflaton potential. For the simplest perturbative reheating scenario, we find the lower bound for a coupling constant of inflaton decay in the E-model and T-model depending on the model parameters. We also find a constraint on the α parameter, α0.01, for the T-model and E-model when we assume a broad resonance reheating scenario.

AB - We investigate a constraint on reheating followed by α-attractor-type inflation (the E-model and T-model) from an observation of the spectral index ns. When the energy density of the Universe is dominated by an energy component with the cosmic equation-of-state parameter wre during reheating, its e-folding number Nre and the reheating temperature Tre are bounded depending on wre. When the reheating epoch consists of two phases - where the energy density of the Universe is dominated by uniform inflaton field oscillations in the first phase and by relativistic nonthermalized particles in the second phase - we find a constraint on the e-folding number of the first oscillation phase, Nsc, depending on the parameters of the inflaton potential. For the simplest perturbative reheating scenario, we find the lower bound for a coupling constant of inflaton decay in the E-model and T-model depending on the model parameters. We also find a constraint on the α parameter, α0.01, for the T-model and E-model when we assume a broad resonance reheating scenario.

UR - http://www.scopus.com/inward/record.url?scp=84964678901&partnerID=8YFLogxK

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U2 - 10.1103/PhysRevD.93.083524

DO - 10.1103/PhysRevD.93.083524

M3 - Article

VL - 93

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 8

M1 - 083524

ER -