Ultra-high energy cosmic rays: Constraints on the maximum-energy distribution of the sources and the possible role of ultra-fast outflows in active galactic nuclei An open question in the search for ultra-high-energy cosmic-ray (UHECR) sources is whether they are few and prominent or if a large population of sources collectively contributes...
Forcing neutrinos to obey the holographic principle Gravity does not like the vast amounts of states present in QFT, and quantum gravitational effects are expected to drastically reduce the dimension of the QFT Hilbert space. This is e.g. achieved by "operator dressing", which changes the commutation relations of quantum fields....
Exploring the Universe at the Highest Energies: when Particle Physics and Astronomy meet High-energy neutrinos propagating over cosmological distances are the ideal messenger particles for astrophysical phenomena, but the neutrino landscape above 10 PeV is still mostly unexplored. At these extreme energies, neutrinos can image the most extreme objects in...