Nonlinear superhorizon perturbations of non-canonical scalar field

2008/10/04 by Yu-ichi Takamizu, Shinji Mukohyama · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph #gr-qc #hep-th

paper · pdf · doi:10.1088/1475-7516/2009/01/013

published as JCAP 0901:013,2009 · 14 pages

arxiv created 2008/10/04 · openalex publication_date 2009/01/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04

Abstract

We develop a theory of non-linear cosmological perturbations at superhorizon scales for a scalar field with a Lagrangian of the form P ( X ,ϕ), where X = −∂ μ ϕ∂ μ ϕ and ϕ is the scalar field. We employ the ADM formalism and the spatial gradient expansion approach to obtain general solutions valid up to the second order in the gradient expansion. This formulation can be applied to, for example, DBI inflation models to investigate superhorizon evolution of non-Gaussianities. With slight modification, we also obtain general solutions valid up to the same order for a perfect fluid with a general equation of state P = P (ρ).

Citations

• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Non-Gaussianity from Inflation: Theory and Observations
• Super-Horizon Scale Dynamics of Multi-Scalar Inflation
• k-Inflation

Cited by

• δMformalism: a new approach to cosmological perturbation theory in anisotropic inflation
• On classification of models of large local-type non-Gaussianity