Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
1993-04-16
Mon.Not.Roy.Astron.Soc. 271 (1994) 976
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
14 pages 2 figures available on request, TeX, IUCAA-12/93
Scientific paper
The growth of density perturbations in an expanding universe in the non-linear regime is investigated. The underlying equations of motion are cast in a suggestive form, and motivate a conjecture that the scaled pair velocity, $h(a,x)\equiv -[v/(\dot{a}x)]$ depends on the expansion factor $a$ and comoving coordinate $x$ only through the density contrast $\sigma(a,x)$. This leads to the result that the true, non-linear, density contrast $<(\delta\rho/\rho)^{2}_{x}>^{1/2}=\sigma(a,x)$ is a universal function of the density contrast $\sigma_L(a,l)$, computed in the linear theory and evaluated at a scale $l$ where $l=x(1+\sigma^2)^{1/3}$. This universality is supported by existing numerical simulations with scale-invariant initial conditions having different power laws. We discuss a physically motivated ansatz $h(a,x)=h[\sigma^2(a,x)]$ and use it to compute the non-linear density contrast at any given scale analytically. This provides a promising method for analysing the non-linear evolution of density perturbations in the universe and for interpreting numerical simulations.
Nityananda Rajaram
Padmanabhan Thanu
No associations
LandOfFree
Scaling properties of the gravitational clustering in the nonlinear regime 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 Scaling properties of the gravitational clustering in the nonlinear regime, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scaling properties of the gravitational clustering in the nonlinear regime will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-190214