Hydrodynamic Approach to the Evolution of Cosmic Structures II: Study of N-body Simulations at z=0

摘要

We present a series of cosmological N-body simulations which make use of thehydrodynamic approach to the evolution of structures (Dominguez 2000). Thisapproach addresses explicitly the existence of a finite spatial resolution andthe dynamical effect of subresolution degrees of freedom. We adapt this methodto cosmological simulations of the standard LCDM structure formation scenarioand study the effects induced at redshift z=0 by this novel approach on thelarge-scale clustering patterns as well as (individual) dark matter halos.Comparing these simulations to usual N-body simulations, we find that (i) thenew (hydrodynamic) model entails a proliferation of low--mass halos, and (ii)dark matter halos have a higher degree of rotational support. These resultsagree with the theoretical expectation about the qualitative behaviour of the"correction terms" introduced by the hydrodynamic approach: these terms act asa drain of inflow kinetic energy and a source of vorticity by the small-scaletidal torques and shear stresses.