HEP Theory Journal Club

Blazar constraints on neutrino-dark matter scattering

Matteo Puel

McGill

Neutrino emission in coincidence with gamma rays has been observed by the IceCube telescope from the blazar TXS 0506+056. Since it is widely believed that dark matter (DM) accrete a black hole analogously to the visible component, we highly expect the presence of a large DM overdensity (i.e. spike) in the central region of the blazar. Therefore, particles in the blazar jet have to travel through this DM spike before being able to reach Earth and likely be detected. The observation of the neutrino from TXS 0506+056 implies new upper bounds on the neutrino-DM scattering cross section as a function of DM mass. In this talk, I will show that the constraint is stronger than existing ones for sub-GeV DM if the cross section rises linearly with energy. For constant cross sections, competitive bounds are also possible depending on details of the DM spike.