Scale-dependent gravitational waves from a rolling axion

Ryo Namba, Marco Peloso, Maresuke Shiraishi, Lorenzo Sorbo, Caner Unal

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

We consider a model in which a pseudo-scalar field σ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and tensor primordial perturbations only through gravitational interactions. These sourced signals are localized on modes that exit the horizon while the roll of σ is significant. We focus our study on cases in which the model can simultaneously produce (i) a large gravitational wave signal, resulting in observable B-modes of the CMB polarizations, and (ii) sufficiently small scalar perturbations, so to be in agreement with the current limits from temperature anisotropies. Different choices of parameters can instead lead to a localized and visible departure from gaussianity in the scalar sector, either at CMB or LSS scales.

Original languageEnglish (US)
Article number041
JournalJournal of Cosmology and Astroparticle Physics
Volume2016
Issue number1
DOIs
StatePublished - Jan 22 2016

Fingerprint

gravitational waves
scalars
large-scale structure of the universe
perturbation
horizon
sectors
tensors
anisotropy
polarization
interactions
temperature

Keywords

  • cosmological perturbation theory
  • ination
  • primordial gravitational waves (theory)

Cite this

Scale-dependent gravitational waves from a rolling axion. / Namba, Ryo; Peloso, Marco; Shiraishi, Maresuke; Sorbo, Lorenzo; Unal, Caner.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2016, No. 1, 041, 22.01.2016.

Research output: Contribution to journalArticle

Namba, Ryo ; Peloso, Marco ; Shiraishi, Maresuke ; Sorbo, Lorenzo ; Unal, Caner. / Scale-dependent gravitational waves from a rolling axion. In: Journal of Cosmology and Astroparticle Physics. 2016 ; Vol. 2016, No. 1.
@article{a5cacc47346a44dfbe5a69f7d5b665dc,
title = "Scale-dependent gravitational waves from a rolling axion",
abstract = "We consider a model in which a pseudo-scalar field σ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and tensor primordial perturbations only through gravitational interactions. These sourced signals are localized on modes that exit the horizon while the roll of σ is significant. We focus our study on cases in which the model can simultaneously produce (i) a large gravitational wave signal, resulting in observable B-modes of the CMB polarizations, and (ii) sufficiently small scalar perturbations, so to be in agreement with the current limits from temperature anisotropies. Different choices of parameters can instead lead to a localized and visible departure from gaussianity in the scalar sector, either at CMB or LSS scales.",
keywords = "cosmological perturbation theory, ination, primordial gravitational waves (theory)",
author = "Ryo Namba and Marco Peloso and Maresuke Shiraishi and Lorenzo Sorbo and Caner Unal",
year = "2016",
month = "1",
day = "22",
doi = "10.1088/1475-7516/2016/01/041",
language = "English (US)",
volume = "2016",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Scale-dependent gravitational waves from a rolling axion

AU - Namba, Ryo

AU - Peloso, Marco

AU - Shiraishi, Maresuke

AU - Sorbo, Lorenzo

AU - Unal, Caner

PY - 2016/1/22

Y1 - 2016/1/22

N2 - We consider a model in which a pseudo-scalar field σ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and tensor primordial perturbations only through gravitational interactions. These sourced signals are localized on modes that exit the horizon while the roll of σ is significant. We focus our study on cases in which the model can simultaneously produce (i) a large gravitational wave signal, resulting in observable B-modes of the CMB polarizations, and (ii) sufficiently small scalar perturbations, so to be in agreement with the current limits from temperature anisotropies. Different choices of parameters can instead lead to a localized and visible departure from gaussianity in the scalar sector, either at CMB or LSS scales.

AB - We consider a model in which a pseudo-scalar field σ rolls for some e-folds during inflation, sourcing one helicity of a gauge field. These fields are only gravitationally coupled to the inflaton, and therefore produce scalar and tensor primordial perturbations only through gravitational interactions. These sourced signals are localized on modes that exit the horizon while the roll of σ is significant. We focus our study on cases in which the model can simultaneously produce (i) a large gravitational wave signal, resulting in observable B-modes of the CMB polarizations, and (ii) sufficiently small scalar perturbations, so to be in agreement with the current limits from temperature anisotropies. Different choices of parameters can instead lead to a localized and visible departure from gaussianity in the scalar sector, either at CMB or LSS scales.

KW - cosmological perturbation theory

KW - ination

KW - primordial gravitational waves (theory)

UR - http://www.scopus.com/inward/record.url?scp=84956597982&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84956597982&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2016/01/041

DO - 10.1088/1475-7516/2016/01/041

M3 - Article

VL - 2016

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 1

M1 - 041

ER -