Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion

Details Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion

2011-07-07

arxiv.org/abs/1107.1281v1

Phys.Rev.D84:023502,2011

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Scientific paper

10.1103/PhysRevD.84.023502

In the full nonlinear cosmological perturbation theory in the leading order of the gradient expansion, all the types of the gauge invariant perturbation variables are defined. The metric junction conditions across the spacelike transition hypersurface are formulated in a manifestly gauge invariant manner. It is manifestly shown that all the physical laws such as the evolution equations, the constraint equations, and the junction conditions can be written using the gauge invariant variables which we defined only. Based on the existence of the universal adiabatic growing mode in the nonlinear perturbation theory and the $\rho$ philosophy where the physical evolution are described using the energy density $\rho$ as the evolution parameter, we give the definitions of the adiabatic perturbation variable and the entropic perturbation variables in the full nonlinear perturbation theory. In order to give the analytic order estimate of the nonlinear parameter $f_{NL}$, we present the exponent evaluation method. As the models where $f_{NL}$ changes continuously and becomes large, using the $\rho$ philosophy, we investigate the non-Gaussianity induced by the entropic perturbation of the component which does not govern the cosmic energy density, and we show that in order to obtain the significant non-Gaussianity it is necessary that the scalar field which supports the entropic perturbation is extremely small compared with the scalar field which supports the adiabatic perturbation.

Affiliated with

Also associated with

No associations

Rating

Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion 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 Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Manifestly gauge invariant theory of the nonlinear cosmological perturbations in the leading order of the gradient expansion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-416430