Micron-sized Extra Dimensions and Primordial Black Holes: Charged, Rotating, and Memory Burdened

TL;DR

This paper investigates six-dimensional primordial black holes as dark matter candidates, analyzing their properties, survival, and potential detection at future colliders, linking extra dimensions, black hole physics, and phenomenology.

Contribution

It introduces a novel scenario where micro black holes with extra dimensions can serve as dark matter, with suppressed evaporation and detectable collider signatures.

Findings

Only PBHs with mass > 10^8 g survive Hawking evaporation.

Memory burden significantly extends the lifetime of near-extremal black holes.

Future colliders could produce high multiplicity events from micro black holes.

Abstract

We explore the possibility of explaining dark matter through six-dimensional (6D) primordial black holes (PBHs) in a theory with two extra dimensions. Interestingly, in this scenario the fundamental energy scale is of the order of $\sim 10$ TeV, accessible by future experiments. We analyse the viability of charged and rotating 6D black holes under standard Hawking evaporation as well as the memory burden scenario. In the case of pure Hawking evaporation, only PBHs with masses $M > 10^8$ g survive to present, while the lifetime of near-extremal configurations is extended by a factor $1/\beta^{1/2}$, where the parameter $\beta$ characterizes small deviations from extremality. In the memory burden scenario evaporation is enormously suppressed, and sub-gram mass PBHs can survive to the present epoch. At future colliders such as the Future Circular Collider, these micro black holes produce characteristic high multiplicity events, $\langle N \rangle \sim 21$, with thermal spectra, enabling direct probes of the fundamental scale and the number of extra dimensions. We find that the memory burden mechanism opens a broad new mass window for light PBH dark matter, while the Kaluza-Klein mass splitting $\Delta m$ aligns with the atmospheric neutrino scale, suggesting a unified framework between Swampland constraints, cosmology, collider physics, and low energy phenomenology.