Incollection,
Quantification of discreteness effects in cosmological N-body simulations
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)
Abstract
The evolution of dark matter in cosmology can be well described as a
self-gravitating fluid. The main technique to calculate the evolution
of this system consists in discretizing the fluid and running N-body
simulations. I will present the problematic of controlling the
discreteness effects in these simulations. I will then describe a
perturbative treatment --- inspired in the Wigner crystal of solid state Physics --- which gives an approximation describing the evolution under self-gravity of
a lattice perturbed from its equilibrium (which is the standard way of
setting-up the initial conditions in the simulations). A quantitative
comparison with fluid Lagrangian theory permits to study precisely
discreteness effects in the linear regime of the system. I will present
also a study of discreteness effects in the non-perturbative
(highly non-linear) regime by evolving different discretizations of
the same continuous density field.
Tags
- clustering
- cosmology
- crystal
- discreteness
- effects
- gravitational
- n-body
- perturbative
- simulations
- statphys23
- theory
- topic-11
- wigner
