Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios

Moliné, Ángeles; Schewtschenko, Jascha A.; Palomares-Ruiz, Sergio; Boehm, Celine; Baugh, Carlton M.

Abstract

The extragalactic γ-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross section into cosmic rays by studying the shape of the energy spectrum. So far all analyses of the extragalactic DM signal have assumed the standard cosmological model (ΛCDM) as the underlying theory. However, there are alternative DM scenarios where the number of low-mass objects is significantly suppressed. Therefore the characteristics of the γ-ray and neutrino emission in these models may differ from ΛCDM as a result. Here we show that the extragalactic isotropic signal in these alternative models has a similar energy dependence to that in ΛCDM, but the overall normalisation is reduced. The similarities between the energy spectra combined with the flux suppression could lead one to misinterpret possible evidence for models beyond ΛCDM as being due to CDM particles annihilating with a much weaker cross section than expected.

Citation

Moliné, Á., Schewtschenko, J. A., Palomares-Ruiz, S., Boehm, C., & Baugh, C. M. (2016). Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios. Journal of Cosmology and Astroparticle Physics, 2016(08), Article 069. https://doi.org/10.1088/1475-7516/2016/08/069

• Journal Article Type: Article
• Acceptance Date: Aug 22, 2016
• Online Publication Date: Aug 30, 2016
• Publication Date: Aug 30, 2016
• Deposit Date: Jun 19, 2016
• Publicly Available Date: Aug 30, 2017
• Journal: Journal of Cosmology and Astroparticle Physics
• Electronic ISSN: 1475-7516
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 2016
• Issue: 08
• Article Number: 069
• DOI: https://doi.org/10.1088/1475-7516/2016/08/069
• Public URL: https://durham-repository.worktribe.com/output/1401995