A&A 385, 761-767 (2002)
Transients from Zel'dovich initial conditionsP. Valageas
Service de Physique Théorique, CEN Saclay, 91191 Gif-sur-Yvette, France
(Received 5 December 2001 / Accepted 29 January 2002 )
We investigate the error implied by the use of the Zel'dovich approximation to set up the initial conditions at a finite redshift in numerical simulations. Using a steepest-descent method developed in a previous work (Valageas 2002a) we derive the probability distribution of the density contrast in the quasi-linear regime. This also provides its dependence on the redshift at which the simulation is started. Thus, we find that the discrepancy with the exact pdf (defined by the limit ) is negligible after the scale factor has grown by a factor , for scales which were initially within the linear regime with . This shows that the use of the Zel'dovich approximation to implement the initial conditions is sufficient for practical purposes since these are not very severe constraints.
Key words: cosmology: theory -- large-scale structure of Universe
© ESO 2002