Gradient expansion approach to multi-field ination

Yuichi Takamizu, Atsushi Naruko, Misao Sasaki

Research output: Contribution to conferencePaper

Abstract

We develop a theory of nonlinear cosmological perturbations on superhorizon scales for a multi-component scalar field with a general kinetic term and a general form of the potential in the context of inationary cosmology. We employ the ADM for- malism and the spatial gradient expansion approach, characterised by O(ε2), where ε = 1=(HL) is a small parameter representing the ratio of the Hubble radius to the characteristic length scale L of perturbations. We provide a formalism to obtain the solution in the multi field case, if we know a complete set of solution of scalar fields. This formalism can be applied to the calculation of the superhorizon evolution of a primordial non-Gaussianity beyond the so-called δN formalism, equivalent to O(ε0).

Original languageEnglish
Pages182-185
Number of pages4
Publication statusPublished - 2011 Jan 1
Event21st Workshop on General Relativity and Gravitation in Japan, JGRG 2011 - Sendai, Japan
Duration: 2011 Sep 262011 Sep 29

Other

Other21st Workshop on General Relativity and Gravitation in Japan, JGRG 2011
CountryJapan
CitySendai
Period11/9/2611/9/29

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Gradient expansion approach to multi-field ination'. Together they form a unique fingerprint.

  • Cite this

    Takamizu, Y., Naruko, A., & Sasaki, M. (2011). Gradient expansion approach to multi-field ination. 182-185. Paper presented at 21st Workshop on General Relativity and Gravitation in Japan, JGRG 2011, Sendai, Japan.