High accuracy power spectra including baryonic physics in dynamical Dark Energy models

Abstract

The next generation mass probes will obtain information on non--linear power spectra P(k,z) and their evolution, allowing us to investigate the nature of Dark Energy. To exploit such data we need high precision simulations, extending at least up to scales of k 10 h/Mpc, where the effects of baryons can no longer be neglected. In this paper, we present a series of large scale hydrodynamical simulations for LCDM and dynamical Dark Energy (dDE) models, in which the equation of state parameter is z-dependent. The simulations include gas cooling, star formation and Supernovae feedback. They closely approximate the observed star formation rate and the observationally derived star/Dark Matter mass ratio in collapsed systems. Baryon dynamics cause spectral shifts exceeding 1% at k > 2-3 h/Mpc compared to pure n-body simulations in the LCDM simulations. This agrees with previous studies, although we find a smaller effect (~50%) on the power spectrum amplitude at higher k's. dDE exhibits similar behavior, even though the dDE simulations produce ~20% less stars than the analogous LCDM cosmologies. Finally, we show that the technique introduced in Casarini et al. to obtain spectra for any $w(z)$ cosmology from constant-w models at any redshift still holds when gas physics is taken into account. While this relieves the need to explore the entire functional space of dark energy state equations, we illustrate a severe risk that future data analysis could lead to misinterpretation of the DE state equation.

12 pages, 13 figures, minor changes to match the accepted version, MNRAS in press

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Cited by in corpus (6)

• Revising the Halofit Model for the Nonlinear Matter Power Spectrum
• DEMNUni: The clustering of large-scale structures in the presence of massive neutrinos
• Effect of baryonic feedback on two- and three-point shear statistics: prospects for detection and improved modelling
• General Requirements on Matter Power Spectrum Predictions for Cosmology with Weak Lensing Tomography
• The clustering of baryonic matter. I: a halo-model approach
• Linear and non-linear perturbations in dark energy models