13-18 December 2015
International Conference Centre Geneva
Europe/Zurich timezone

Constraining sterile neutrinos with lyman alpha forest

15 Dec 2015, 16:57
21m
Level -1, Room 16 (International Conference Centre Geneva)

Level -1, Room 16

International Conference Centre Geneva

17 Rue de Varembé, 1211 Geneva

Speaker

Dr Antonella Garzilli (Leiden University)

Description

We reconsider the problem of determining the warmness of dark matter from the growth of large scale structures. In particular, we have re-analyzed the previous work of Viel et al 2013, based on high resolution Lyman-alpha forest spectra. In fact, the flux power spectrum exhibits a cut-off below ~ 1.5 Mpc/h, this may be explained by the temperature of the intergalactic medium (IGM) or be due to the free-streaming of dark matter particles. We show that if the IGM temperature at high redshifts was low enough (rising at later times) then the data indeed prefer warm dark matter. Assuming this broader range of thermal histories, we find that mWDM >= 2.1 keV for thermal relic at 95% CL (mNRP >= 12 keV for non-resonantly produced sterile neutrino). We discuss an independent method that would allow to exclude the influence of WDM on observable small-scale structures, or would lead to the discovery of WDM. We also determine values of lepton asymmetry making resonantly produced 7 keV sterile neutrinos consistent with the data.

Primary author

Dr Antonella Garzilli (Leiden University)

Co-authors

Oleg Ruchayskiy (Ecole Polytechnique Federale de Lausanne (CH)) Oleksii Boiarskyi (Leiden University (NL))

Presentation Materials