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Dark matter annihilations and 21cm signal
Submitted by Laura lopez Honorez on 29 Mar 2016 at 11:43
Id: 92
Last modification: 29 Mar 2016 11:43
Abstract
Dark matter (DM) annihilations into charged particles change the
thermal history of the Universe and, as a consequence, affect the
21 cm signal. In my talk I will discuss how predicting the effect
of DM strongly relies on the modeling of annihilations inside
halos. Given current uncertainties on the description of the
astrophysical processes driving the epochs of reionization, X-ray
heating and Lyman-α pumping, we found in a recent work that
disentangling DM signatures from purely astrophysical effects,
related to early-time star formation processes or late-time
galaxy X-ray emissions, will be a challenging task. We have
concluded that only annihilations of DM particles with masses of
∼100 MeV, could leave an unambiguous imprint on the 21 cm signal
and, in particular, on the 21 cm power spectrum. Additional
measurements of the 21 cm signal at different cosmic epochs
should help to break the strong parameter degeneracies between DM
annihilations and astrophysical effects in order to undoubtedly
single out a DM imprint for masses different from ∼100 MeV.
| Based on (arXiv number) | http://arxiv.org/abs/1603.06795 |
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