Diffuse Neutrino Signals from Dark Stars Seeding Super-Massive Black Holes

Abstract: Dark stars (DSs) -- first stars powered by dark-matter (DM) heating rather than fusion -- could form in the early Universe. They can grow to $\gtrsim 10^5 M_{\odot}$ masses and collapse into seeds of supermassive black holes (SMBHs). We demonstrate that diffuse neutrino flux generated by DSs can be observable in existing experiments and have energies reaching hundreds of MeV, providing novel window for probing SMBH progenitors. We establish first constraints on DSs and DM annihilations powering them using data from Super-Kamiokande and IceCube neutrino experiments, and consistent with James Webb Space Telescope observations. Upcoming experiments such as Hyper-Kamiokande, DUNE, JUNO will be able to explore DS properties with enhanced sensitivity.