1109.5695 (Marco Baldi)

The CoDECS project: a publicly available suite of cosmological N-body
simulations for interacting dark energy models    [PDF]

Marco Baldi

We present the largest set of N-body and hydrodynamical simulations to date
for cosmological models featuring a direct interaction between the Dark Energy
(DE) scalar field, responsible of the observed cosmic acceleration, and the
Cold Dark Matter (CDM) fluid. With respect to previous works, our simulations
considerably extend the statistical significance of the simulated volume and
cover a wider range of different realizations of the interacting DE scenario,
including the recently proposed bouncing coupled DE model. Furthermore, all the
simulations are normalized in order to be consistent with the present bounds on
the amplitude of density perturbations at last scattering, thereby providing
the first realistic determination of the effects of a DE coupling for
cosmological growth histories fully compatible with the latest Cosmic Microwave
Background data. As a first basic analysis, we have studied the impact of the
coupling on the nonlinear matter power spectrum and on the bias between the CDM
and baryon distributions, as a function of redshift and scale. For the former,
we have addressed the issue of the degeneracy between the effects of the
coupling and other standard cosmological parameters, as e.g sigma_8, showing
how the redshift evolution of the linear amplitude or the scale dependence of
the nonlinear power spectrum might provide a way to break the degeneracy. For
the latter, instead, we have computed the redshift and scale dependence of the
bias in all our different models showing how a growing coupling or a bouncing
coupled DE scenario provide much stronger effects with respect to constant
coupling models. We refer to this vast numerical initiative as the COupled Dark
Energy Cosmological Simulations project, or CoDECS, and we hereby release all
the CoDECS outputs for public use through a dedicated web database, providing
information on how to access and interpret the data.

View original: http://arxiv.org/abs/1109.5695