Novel constraints on non-cold (non-thermal) Dark Matter from Lyman-$α$ forest data [CEA]

http://arxiv.org/abs/1806.08371


In this paper we present an efficient method for constraining both thermal and non-thermal Dark Matter (DM) scenarios with the Lyman-$\alpha$ forest, based on a simple and flexible parametrisation capable to reproduce the small scale clustering signal of a large set of non-cold DM (nCDM) models. By using a large suite of hydrodynamic simulations, we determine constraints on both astrophysical, cosmological, and nCDM parameters by performing a full Monte Carlo Markov Chain (MCMC) analysis. We obtain a marginalised upper limit on the largest possible scale at which a power suppression induced by nearly any nCDM scenario can occur, i.e. $\alpha<0.03~{\rm{Mpc}}/h$ (2$\sigma$ C.L.). We explicitly describe how to test several of the most viable nCDM scenarios without the need to run any specific numerical simulations, due to the novel parametrisation proposed, and due to a new scheme that interpolates between the cosmological models explored. The shape of the linear matter power spectrum for standard thermal warm DM models appear to be in mild tension ($\sim 2\sigma$ C.L.) with the data, compared to non-thermal scenarios. This is the first study that allows to probe the linear small scale shape of the DM power spectrum for a large set of nCDM models.

Read this paper on arXiv…

R. Murgia, V. Iršič and M. Viel
Mon, 25 Jun 18
26/54

Comments: 15 pages, 7 figures, 3 tables