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Description
As other Standard Model particles, neutrinos can be emitted in dark matter pair-annihilation or decay processes. However, unlike other messengers, neutrinos undergo neither deflection nor absorption over cosmic distances, making them an ideal probe for inspecting dark matter interactions in astrophysical sources, potentially yielding sizeable, high-energy fluxes. Besides, neutrinos can scan very luminous regions such as the Galactic Centre, where a major dark matter reservoir is expected, with a minimal nuisance from background. Neutrino telescopes also have a unique opportunity to look at the Sun, probing interactions of dark matter from the Galactic halo accumulating in its interior.
KM3NeT is a multi-purpose neutrino observatory composed of underwater Cherenkov arrays installed in the Mediterranean Sea. Given its latitude and its ability to measure up-going neutrinos that propagate through the Earth, KM3NeT has the Milky Way Centre in sight for about 70% of the time. Thanks to the optical properties of water KM3NeT has an excellent performance in the reconstruction of coordinates, energy and flavour of neutrino events. Its coverage spans an energy range from the GeV to tens of PeV, opening a broad window onto various dark matter candidate masses. KM3NeT has conducted indirect searches for neutrinos produced in pair annihilations of WIMPs (weakly interacting massive particles), characterising potential signatures from the Galactic Centre using an unbinned maximum likelihood algorithm. Similarly, KM3NeT constrains the WIMP-nucleon scattering cross section occurring in the Sun providing limits that complement the landscape of direct searches. Beyond standard WIMPs, neutrinos probe alternative scenarios, such as heavy dark matter in a secluded scenario, or light dark matter boosted or upscattered by cosmic rays. The decay of a heavy dark matter particle was tested as a possible source for the extreme energy of KM3-230213A, a recently observed neutrino event, still lacking a conclusive astrophysical origin. Utilizing a modular layout, KM3NeT is continuously expanding while actively recording data in its partial configurations. This work presents the latest results obtained from these recently installed configurations.