Thierry Baertschiger

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We analyse with simple real-space statistics the Virgo consortium's cosmological N-body simulations. Significant clustering rapidly develops well below the initial mean interparticle separation Λ i , where the gravitational force on a particle is dominated by that with its nearest neighbours. A power-law behaviour in the two point correlation function(More)
The effects of discreteness arising from the use of the N-body method on the accuracy of simulations of cosmological structure formation are not currently well understood. In the first part of this paper we discuss the essential question of how the relevant parameters introduced by this discretisation should be extrapolated in convergence studies if the(More)
In two recent papers, a detailed study has been presented of the out-of-equilibrium dynamics of an infinite system of self-gravitating points initially located on a randomly perturbed lattice. In this paper, we extend the treatment of the early time phase during which strong nonlinear correlations first develop, prior to the onset of "self-similar" scaling(More)
– We present an analysis of different sets of gravitational N-body simulations, all describing the dynamics of discrete particles with a small initial velocity dispersion. They encompass very different initial particle configurations, different numerical algorithms for the computation of the force, with or without the space expansion of cosmological models.(More)
In this lecture we address three different but related aspects of the initial continuous fluctuation field in standard cosmological models. Firstly we discuss the properties of the so-called Harrison-Zeldovich like spectra. This power spectrum is a fundamental feature of all current standard cosmological models. In a simple classification of all stationary(More)
(received ; accepted) PACS. 05.20−y – Statistical Mechanics. PACS. 98.65−r – Large scale structure of the Universe. Abstract. – Cosmological N-body simulations aim to calculate the non-linear gravitational growth of structures via particle dynamics. A crucial problem concerns the setting-up of the initial particle distribution, as standard theories of(More)
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