Observing micro-black-hole dark matter
Abstract
Primordial micro black holes can constitute dark matter if short-distance gravity is modified by extra dimensions or a large number of species and if the memory-burden effect sufficiently suppresses Hawking evaporation. The resulting black holes in the transition regime differ from their four-dimensional Einsteinian counterparts through their mass—radius relation, temperature, entropy, and lifetime, which can render even very light objects cosmologically stable. The most promising observational consequences of such micro black hole dark matter are analyzed. Neutron star survival yields the most robust constraints, while a narrow region of parameter space can simultaneously remain viable and address the missing-pulsar problem in the Galactic Center. Diffuse evaporation signals in neutrino telescopes are found to be relevant mainly in extradimensional scenarios, whereas in generic species models, visible emission is strongly suppressed by evaporation into dark sectors. Merger-induced evaporation bursts can provide an additional probe in extradimensional realizations if the postmerger remnant briefly returns to the semiclassical phase. Overall, micro-black-hole dark matter remains phenomenologically viable in constrained regions, with neutron stars, neutrino telescopes, and merger signatures providing complementary tests.
Related
- Clarifications on black/white hole metastable relics as dark matter
- Shadow of rotating black hole surrounded by dark matter
- Exploring Exact Einsteinian Black Hole Physics in Dark Matter Environment: Ray Tracing, Stability, Eikonal QNMs and Thermodynamics
- Periodic Orbits and Their Gravitational-Wave Signatures around a Rotating Black Hole Surrounded by Perfect Fluid Dark Matter
- Radiating Bardeen Black-Hole as a dark matter candidate
BibTeX
@article{ettengruber2026observing,
title = {{Observing micro-black-hole dark matter}},
author = {Manuel Ettengruber and Florian Kühnel},
journal = {Phys.Rev.D},
year = {2026},
month = oct,
doi = {10.1103/rm1g-qtk7},
eprint = {2603.15764},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05842216v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Observing micro-black-hole dark matter
AU - Manuel Ettengruber
AU - Florian Kühnel
PY - 2026
DA - 2026/10/28
JO - Phys.Rev.D
DO - 10.1103/rm1g-qtk7
UR - https://hal.science/hal-05842216v1
AB - Primordial micro black holes can constitute dark matter if short-distance gravity is modified by extra dimensions or a large number of species and if the memory-burden effect sufficiently suppresses Hawking evaporation. The resulting black holes in the transition regime differ from their four-dimensional Einsteinian counterparts through their mass—radius relation, temperature, entropy, and lifetime, which can render even very light objects cosmologically stable. The most promising observational consequences of such micro black hole dark matter are analyzed. Neutron star survival yields the most robust constraints, while a narrow region of parameter space can simultaneously remain viable and address the missing-pulsar problem in the Galactic Center. Diffuse evaporation signals in neutrino telescopes are found to be relevant mainly in extradimensional scenarios, whereas in generic species models, visible emission is strongly suppressed by evaporation into dark sectors. Merger-induced evaporation bursts can provide an additional probe in extradimensional realizations if the postmerger remnant briefly returns to the semiclassical phase. Overall, micro-black-hole dark matter remains phenomenologically viable in constrained regions, with neutron stars, neutrino telescopes, and merger signatures providing complementary tests.
ER -