Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-04-14
MNRAS 292, p225-242, 1997
Astronomy and Astrophysics
Astrophysics
20 pages, latex (mn.sty), 4 figures, to be published by MNRAS
Scientific paper
The formalism that describes the non-linear growth of the angular momentum L of protostructures from tidal torques in a Friedmann Universe, as developed in a previous paper, is extended to include non-Gaussian initial conditions. We restrict our analysis here to a particular class of non-Gaussian primordial distributions, namely multiplicative models. In such models, strongly correlated phases are produced by obtaining the gravitational potential via a nonlinear local transformation of an underlying Gaussian random field. The dynamical evolution of the system is followed by describing the trajectories of fluid particles using second-order Lagrangian perturbation theory. In the Einstein-de Sitter universe, the lowest-order perturbative correction to the variance of the linear angular momentum of collapsing structures grows as t^8/3 for generic non-Gaussian statistics, which contrasts with the t^10/3 growth rate characteristic of Gaussian statistics. This is a consequence of the fact that the lowest-order perturbative spin contribution in the non-Gaussian case arises from the third moment of the gravitational potential, which is identically zero for a Gaussian field. Evaluating these corrections at the maximum expansion time of the collapsing structure, we find that these non-Gaussian and non-linear terms can be as high as the linear estimate, without the degree of non-Gaussianity as quantified by skewness and kurtosis of the density field being unacceptably large. The results suggest that higher-order terms in the perturbative expansion may contribute significantly to galactic spin which contrasts with the straightforward Gaussian case.
Catelan Paolo
Theuns Tom
No associations
LandOfFree
Non-linear evolution of the tidal angular momentum of protostructures II: non-Gaussian initial conditions 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 Non-linear evolution of the tidal angular momentum of protostructures II: non-Gaussian initial conditions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-linear evolution of the tidal angular momentum of protostructures II: non-Gaussian initial conditions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-262457