Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-08-18
JCAP 04 (2011) 030
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
23 pages, plus appendices and references; 4 figures. v2: incorrect statements regarding numerical delta N removed from Sec. 4.
Scientific paper
10.1088/1475-7516/2011/04/030
In a recent publication, we proposed that inflationary perturbation theory can be reformulated in terms of a probability transport equation, whose moments determine the correlation properties of the primordial curvature perturbation. In this paper we generalize this formulation to an arbitrary number of fields. We deduce ordinary differential equations for the evolution of the moments of zeta on superhorizon scales, which can be used to obtain an evolution equation for the dimensionless bispectrum, fNL. Our equations are covariant in field space and allow identification of the source terms responsible for evolution of fNL. In a model with M scalar fields, the number of numerical integrations required to obtain solutions of these equations scales like O(M^3). The performance of the moment transport algorithm means that numerical calculations with M >> 1 fields are straightforward. We illustrate this performance with a numerical calculation of fNL in Nflation models containing M ~ 10^2 fields, finding agreement with existing analytic calculations. We comment briefly on extensions of the method beyond the slow-roll approximation, or to calculate higher order parameters such as gNL.
Mulryne David J.
Seery David
Wesley Daniel
No associations
LandOfFree
Moment transport equations for the primordial curvature perturbation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Moment transport equations for the primordial curvature perturbation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moment transport equations for the primordial curvature perturbation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-134305