Primordial black holes are five dimensional
Luis A. Anchordoqui (Department of Physics and Astronomy, Lehman College, City University of New York, New York 10468, USA, Department of Physics, Graduate Center, City University of New York, New York 10016, USA, Department of Astrophysics, American Museum of Natural History, New York 10024, USA)
; Alek Bedroya (Princeton Gravity Initiative, Princeton University, Princeton, New Jersey 08544, USA); Dieter Lüst (Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität München, 80333 München, Germany, Max–Planck–Institut für Physik, Werner–Heisenberg–Institut, Boltzmannstraße 8, 85748 Garching, Germany)
We revisit well-established mechanisms for primordial black hole (PBH) production, namely inflation, phase transitions, and cosmic strings, in the context of the dark dimension scenario, which is motivated by swampland principles. Applying quantum gravity constraints, we demonstrate that any viable mechanism, barring exotic new physics at low energies, inevitably leads to the formation of five-dimensional PBHs. We further show that PBHs formed from cosmic strings can have lifetimes comparable to the age of the Universe. We comment on the observational implications of this result, including a potential connection to the recent detection of a high-energy neutrino by KM3NeT, whose energy is intriguingly close to the five-dimensional Planck scale in the dark dimension scenario.
