The Non-Linear Matter Power Spectrum in Warm Dark Matter Cosmologies

INFN/National Institute for Nuclear Physics, I-34127, Trieste, Italy
Monthly Notices of the Royal Astronomical Society (Impact Factor: 5.11). 07/2011; 000(1). DOI: 10.1111/j.1365-2966.2011.19910.x
Source: arXiv


We investigate the non-linear evolution of the matter power spectrum by using
a large set of high-resolution N-body/hydrodynamic simulations. The linear
matter power in the initial conditions is consistently modified to accommodate
warm dark matter particles which induce a small scale cut-off in the power as
compared to standard cold dark matter scenarios. The impact of such thermal
relics is addressed at small scales with k > 1 h/Mpc and at z < 5, which are
particularly important for the next generation of Lyman-alpha forest, weak
lensing and galaxy clustering surveys. We quantify the mass and redshift
dependence of the warm dark matter non-linear matter power and we provide a
fitting formula which is accurate at the ~2% level below z=3 and for masses
m_wdm > 0.5 keV. The role of baryonic physics (cooling, star formation and
feedback recipes) on the warm dark matter induced suppression is also
quantified. Furthermore, we compare our findings with the halo model and show
their impact on the cosmic shear power spectra.

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