Astrophysical turbulent plasmas as extreme particle accelerators and sources of very high-energy neutrinos

Abstract: How magnetized turbulent plasmas can accelerate charged particles to high energies forms a long-standing question with far-reaching implications for multi-messenger astrophysics. It indeed goes back to the seminal works of Enrico Fermi in the late 1940s and nowadays, it is commonly invoked to model the generation of non-thermal particle spectra in a broad variety of astrophysical sites, including extreme, relativistic sources such as black hole accretion disks, pulsar wind nebulae, or relativistic jets from active galactic nuclei. In a first part, this seminar will summarize recent progress in this area and propose a modern theoretical picture of the physics at play, which can be regarded as a generalization of the original Fermi scenario. In a second part, these results will be placed in the context of magnetized turbulent coronae of active galactic nuclei to understand if and how this process can explain the origin of high-energy neutrinos recently detected by the Ice Cube experiment in the direction of Seyfert galaxies.