Ponente
Descripción
Observations of high-energy astrophysical neutrinos in IceCube have opened the door to multi-messenger astronomy, by way of which questions in particle physics could be explored collaboratively between IceCube and optical experiments such as Fermi-LAT. However, the origin of these astrophysical neutrinos is still largely unknown. Among the tensions that still need to be resolved, for example, is the excess of neutrinos in the High Energy Starting Event (HESE) sample in the energy range of 40-200 TeV, a contribution that could come from dark matter decay. The dark matter decay hypothesis can be tested through comparisons with Fermi-LAT gamma-ray data. In particular, HESE predicts a soft neutrino spectrum that extends below around 50 TeV, but such a spectrum is incompatible with current gamma ray measurements and suggests that gamma-rays become heavily suppressed for sources dominating in this lower-energy range. A reason for this is that properties of the traversed medium, which consists of extragalactic background light (EBL), the cosmic microwave background (CMB), and the intergalactic magnetic field, significantly alter the final gamma ray spectrum that reaches telescopes on Earth. The existence of competing EBL models, moreover, complicates estimates of dark matter constraints. In this presentation, we address these questions by studying the impact that the EBL has on indirect measurements of dark matter decay. I present my predictions for galactic, inverse-Compton, and extragalactic gamma-ray spectra undergoing attenuation by different EBL models.
