Could five-dimensional primordial black holes explain dark matter observations?

A stronger interpretation argues that the dark-dimension framework may make five-dimensional primordial black holes more than merely possible: quantum-gravity constraints could make them the generic outcome of several formation mechanisms, and some could live for roughly the age of the universe. This reading is provocative and highly conditional, especially where it invokes kination, Kaluza–Klein-graviton stability, memory-burden effects, or a possible neutrino connection.

• One proposal argues that, within the dark-dimension scenario, viable inflationary, phase-transition, or cosmic-string mechanisms generically produce five-dimensional primordial black holes unless low-energy exotic physics intervenes.
• Cosmic-string-produced five-dimensional primordial black holes are proposed to have lifetimes comparable to the age of the universe.
• Rotating five-dimensional black holes with a memory-burden suppression of evaporation are proposed to open a broad present-day dark-matter mass window.
• A review describes the all-five-dimensional claim as provocative but conditional, highlighting the need to check the stability of Kaluza–Klein gravitons.
• A high-energy neutrino has been proposed as a possible observational connection, but other astrophysical explanations remain possible.

Featured sourceNeutrinos from Primordial Black Holes in Theories with Extra Dimensionsarxiv.org7 sourcesView sources