Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation

Shuntaro Mizuno, Ryo Saito, David Langlois

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

We investigate the features generated by a sharp turn along the inflationary trajectory in a two-field model of Dirac-Born-Infeld inflation, where one of the fields is heavy. Distinct features are generated by two different effects: the mixing of the light and heavy modes during the turn, on the one hand, and the resonance between the oscillations along the heavy direction after the turn, on the other hand. Contrary to models with standard kinetic terms, the resonance effect is not strongly suppressed because the action contains derivative interactions. Working in the potential basis, we study the oscillations after the turn and compute the amplitude of the mixing and resonance features in the power spectrum, as well as in the bispectrum for the latter effect. We find that the amplitudes and positions of these combined features obey specific consistency relations, which could be confronted with cosmological data.

Original languageEnglish
Article number032
JournalJournal of Cosmology and Astroparticle Physics
Volume2014
Issue number11
DOIs
Publication statusPublished - 2014 Nov 1
Externally publishedYes

Fingerprint

oscillations
power spectra
trajectories
kinetics
interactions

Keywords

  • Cosmological perturbation theory
  • Inflation

ASJC Scopus subject areas

  • Astronomy and Astrophysics

Cite this

Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation. / Mizuno, Shuntaro; Saito, Ryo; Langlois, David.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2014, No. 11, 032, 01.11.2014.

Research output: Contribution to journalArticle

@article{00a5dc572bec4843bd7d283ad89a6cf4,
title = "Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation",
abstract = "We investigate the features generated by a sharp turn along the inflationary trajectory in a two-field model of Dirac-Born-Infeld inflation, where one of the fields is heavy. Distinct features are generated by two different effects: the mixing of the light and heavy modes during the turn, on the one hand, and the resonance between the oscillations along the heavy direction after the turn, on the other hand. Contrary to models with standard kinetic terms, the resonance effect is not strongly suppressed because the action contains derivative interactions. Working in the potential basis, we study the oscillations after the turn and compute the amplitude of the mixing and resonance features in the power spectrum, as well as in the bispectrum for the latter effect. We find that the amplitudes and positions of these combined features obey specific consistency relations, which could be confronted with cosmological data.",
keywords = "Cosmological perturbation theory, Inflation",
author = "Shuntaro Mizuno and Ryo Saito and David Langlois",
year = "2014",
month = "11",
day = "1",
doi = "10.1088/1475-7516/2014/11/032",
language = "English",
volume = "2014",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "11",

}

TY - JOUR

T1 - Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation

AU - Mizuno, Shuntaro

AU - Saito, Ryo

AU - Langlois, David

PY - 2014/11/1

Y1 - 2014/11/1

N2 - We investigate the features generated by a sharp turn along the inflationary trajectory in a two-field model of Dirac-Born-Infeld inflation, where one of the fields is heavy. Distinct features are generated by two different effects: the mixing of the light and heavy modes during the turn, on the one hand, and the resonance between the oscillations along the heavy direction after the turn, on the other hand. Contrary to models with standard kinetic terms, the resonance effect is not strongly suppressed because the action contains derivative interactions. Working in the potential basis, we study the oscillations after the turn and compute the amplitude of the mixing and resonance features in the power spectrum, as well as in the bispectrum for the latter effect. We find that the amplitudes and positions of these combined features obey specific consistency relations, which could be confronted with cosmological data.

AB - We investigate the features generated by a sharp turn along the inflationary trajectory in a two-field model of Dirac-Born-Infeld inflation, where one of the fields is heavy. Distinct features are generated by two different effects: the mixing of the light and heavy modes during the turn, on the one hand, and the resonance between the oscillations along the heavy direction after the turn, on the other hand. Contrary to models with standard kinetic terms, the resonance effect is not strongly suppressed because the action contains derivative interactions. Working in the potential basis, we study the oscillations after the turn and compute the amplitude of the mixing and resonance features in the power spectrum, as well as in the bispectrum for the latter effect. We find that the amplitudes and positions of these combined features obey specific consistency relations, which could be confronted with cosmological data.

KW - Cosmological perturbation theory

KW - Inflation

UR - http://www.scopus.com/inward/record.url?scp=84914666066&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84914666066&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2014/11/032

DO - 10.1088/1475-7516/2014/11/032

M3 - Article

VL - 2014

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 11

M1 - 032

ER -