Near Threshold Kaluza-Klein Graviton Decays and the Dark Dimension
Abstract
Near threshold, intra-tower decays of Kaluza-Klein (KK) gravitons are pure d-wave, with rate Γ∝ p5 in the decay products momentum p, rather than the s-wave Γ∝ p assumed in the dark dimension literature. In a flat dark dimension this excludes KK gravitons as a dark matter candidate. Even if some other source of dark matter is assumed, the irreducible freeze-in abundance of KK gravitons produce MeV gamma rays which allows one to set upper limits on the reheating temperature; additionally using the lower bound on the reheating temperature from big-bang nucleosynthesis and the cosmic microwave background requires the radius of the extra dimension to be almost three orders of magnitude smaller than the distance conjecture would naively prefer, R∼ Λ−1/4.
Related
- Evidence for Kaluza-Klein excitations of the graviton, gluon and quark at LHC
- A Universal Kaluza-Klein Graviton Cascade Rate
- A strategy for a Kaluza-Klein graviton discovery at LHC
- Multi-rotating black holes with non-aligned angular momenta in 5D Kaluza-Klein theory
- Gauge-invariant thermodynamic description of rotating black strings in 5D minimal supergravity via Kaluza-Klein reduction
BibTeX
@misc{langhoff2026near,
title = {{Near Threshold Kaluza-Klein Graviton Decays and the Dark Dimension}},
author = {Kevin Langhoff},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.01825},
eprint = {2610.01825},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.01825},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Near Threshold Kaluza-Klein Graviton Decays and the Dark Dimension
AU - Kevin Langhoff
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.01825
UR - https://arxiv.org/abs/2610.01825
AB - Near threshold, intra-tower decays of Kaluza-Klein (KK) gravitons are pure d-wave, with rate Γ∝ p^5 in the decay products momentum p, rather than the s-wave Γ∝ p assumed in the dark dimension literature. In a flat dark dimension this excludes KK gravitons as a dark matter candidate. Even if some other source of dark matter is assumed, the irreducible freeze-in abundance of KK gravitons produce MeV gamma rays which allows one to set upper limits on the reheating temperature; additionally using the lower bound on the reheating temperature from big-bang nucleosynthesis and the cosmic microwave background requires the radius of the extra dimension to be almost three orders of magnitude smaller than the distance conjecture would naively prefer, R∼ Λ^−1/4.
ER -