Vlasov limit and discreteness effects in cosmological N-body simulations |
| |
Institution: | 1. Dipartimento di Fisica, Universita’ di Pisam, Largo Pontecorvo 3, 56127 Pisa - Italy;2. Institut de Physique et Chimie des Matériaux de Strasbourg, 23, rue du Loess - BP 43 F-67034 Strasbourg, France |
| |
Abstract: | We present the problematic of controlling the discreteness effects in cosmological N-body simulations. We describe a perturbative treatment which gives an approximation describing the evolution under self-gravity of a lattice perturbed from its equilibrium, which allows to trace the evolution of the fully discrete distribution until the time when particles approach one another (“shell-crossing”). Perturbed lattices are typical initial conditions for cosmological N-body simulations and thus we can describe precisely the early time evolution of these simulations. A quantitative comparison with fluid Lagrangian theory permits to study discreteness effects in the linear regime of the simulations. We show finally some work in progress about quantifying discreteness effects in the non-perturbative (highly non-linear) regime of cosmological N-body simulations by evolving different discretizations of the same continuous density field. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|