Covariant second-order perturbations in generalized two-field inflation

Eleftheria Tzavara, Shuntaro Mizuno, Bartjan Van Tent

研究成果: Article

3 引用 (Scopus)

抄録

We examine the covariant properties of generalized models of two-field inflation, with non-canonical kinetic terms and a possibly non-trivial field metric. We demonstrate that kinetic-term derivatives and covariant field derivatives do commute in a proper covariant framework, which was not realized before in the literature. We also define a set of generalized slow-roll parameters, using a unified notation. Within this framework, we study the most general class of models that allows for well-defined adiabatic and entropic sound speeds, which we identify as the models with parallel momentum and field velocity vectors. For these models we write the exact cubic action in terms of the adiabatic and isocurvature perturbations. We thus provide the tool to calculate the exact non-Gaussianity beyond slow-roll and at any scale for these generalized models. We illustrate our general results by considering their long-wavelength limit, as well as with the example of two-field DBI inflation.

元の言語English
記事番号027
ジャーナルJournal of Cosmology and Astroparticle Physics
2014
発行部数7
DOI
出版物ステータスPublished - 2014 7 1
外部発表Yes

Fingerprint

perturbation
kinetics
coding
velocity distribution
momentum
acoustics
wavelengths

ASJC Scopus subject areas

  • Astronomy and Astrophysics

これを引用

Covariant second-order perturbations in generalized two-field inflation. / Tzavara, Eleftheria; Mizuno, Shuntaro; Tent, Bartjan Van.

:: Journal of Cosmology and Astroparticle Physics, 巻 2014, 番号 7, 027, 01.07.2014.

研究成果: Article

Tzavara, Eleftheria ; Mizuno, Shuntaro ; Tent, Bartjan Van. / Covariant second-order perturbations in generalized two-field inflation. :: Journal of Cosmology and Astroparticle Physics. 2014 ; 巻 2014, 番号 7.
@article{90d326a628f0479c9617048ed423ed8e,
title = "Covariant second-order perturbations in generalized two-field inflation",
abstract = "We examine the covariant properties of generalized models of two-field inflation, with non-canonical kinetic terms and a possibly non-trivial field metric. We demonstrate that kinetic-term derivatives and covariant field derivatives do commute in a proper covariant framework, which was not realized before in the literature. We also define a set of generalized slow-roll parameters, using a unified notation. Within this framework, we study the most general class of models that allows for well-defined adiabatic and entropic sound speeds, which we identify as the models with parallel momentum and field velocity vectors. For these models we write the exact cubic action in terms of the adiabatic and isocurvature perturbations. We thus provide the tool to calculate the exact non-Gaussianity beyond slow-roll and at any scale for these generalized models. We illustrate our general results by considering their long-wavelength limit, as well as with the example of two-field DBI inflation.",
keywords = "cosmological applications of theories with extra dimensions, cosmological perturbation theory, inflation, non-gaussianity",
author = "Eleftheria Tzavara and Shuntaro Mizuno and Tent, {Bartjan Van}",
year = "2014",
month = "7",
day = "1",
doi = "10.1088/1475-7516/2014/07/027",
language = "English",
volume = "2014",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "7",

}

TY - JOUR

T1 - Covariant second-order perturbations in generalized two-field inflation

AU - Tzavara, Eleftheria

AU - Mizuno, Shuntaro

AU - Tent, Bartjan Van

PY - 2014/7/1

Y1 - 2014/7/1

N2 - We examine the covariant properties of generalized models of two-field inflation, with non-canonical kinetic terms and a possibly non-trivial field metric. We demonstrate that kinetic-term derivatives and covariant field derivatives do commute in a proper covariant framework, which was not realized before in the literature. We also define a set of generalized slow-roll parameters, using a unified notation. Within this framework, we study the most general class of models that allows for well-defined adiabatic and entropic sound speeds, which we identify as the models with parallel momentum and field velocity vectors. For these models we write the exact cubic action in terms of the adiabatic and isocurvature perturbations. We thus provide the tool to calculate the exact non-Gaussianity beyond slow-roll and at any scale for these generalized models. We illustrate our general results by considering their long-wavelength limit, as well as with the example of two-field DBI inflation.

AB - We examine the covariant properties of generalized models of two-field inflation, with non-canonical kinetic terms and a possibly non-trivial field metric. We demonstrate that kinetic-term derivatives and covariant field derivatives do commute in a proper covariant framework, which was not realized before in the literature. We also define a set of generalized slow-roll parameters, using a unified notation. Within this framework, we study the most general class of models that allows for well-defined adiabatic and entropic sound speeds, which we identify as the models with parallel momentum and field velocity vectors. For these models we write the exact cubic action in terms of the adiabatic and isocurvature perturbations. We thus provide the tool to calculate the exact non-Gaussianity beyond slow-roll and at any scale for these generalized models. We illustrate our general results by considering their long-wavelength limit, as well as with the example of two-field DBI inflation.

KW - cosmological applications of theories with extra dimensions

KW - cosmological perturbation theory

KW - inflation

KW - non-gaussianity

UR - http://www.scopus.com/inward/record.url?scp=84904978728&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84904978728&partnerID=8YFLogxK

U2 - 10.1088/1475-7516/2014/07/027

DO - 10.1088/1475-7516/2014/07/027

M3 - Article

AN - SCOPUS:84904978728

VL - 2014

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - 7

M1 - 027

ER -