Kissing number in dimension 18
- upper bound 16,406by David de Laat and Nando Leijenhorstarxiv.org
- lower bound 7654by Henry Cohn and Anqi Liarxiv.org
- lower bound 8358by Alexander Kravatskiygithub.com
- Last checked
Cite this frontier
DiscoverIA. Kissing number in dimension 18 [Frontier, checked on Oct 12, 2026]. DiscoverIA registry. https://discoveria.ai/en/frontieres/kissing-d18/
The exact value lies somewhere in between, within a factor of ×1.96. The lower bound has moved 2 times since 1967, most recently on Sep 16, 2026. The upper bound has not moved since 2022.
The maximum number of unit spheres with disjoint interiors that can touch a central unit sphere in R^18. A valid configuration of N spheres gives the lower bound N; a linear or semidefinite programming bound gives an upper bound.
Exact value unknown: gap 8358 versus 16406 (ratio 1.963 on Cohn's table consulted 2026-10-13). Lower bounds are explicit constructions (the recent ones announce an exact-arithmetic program check); no named third-party review appears in the sources read. The sources read declare AI use for these lower bounds: Claude Code (8358, 2026-09-16). The latest (8358, Alexander Kravatskiy, 2026-09-16) has AI use declared by its source. The upper bound (16406) is a semidefinite programming bound (Cohn's table, credited to Leijenhorst-de Laat); no source read attributes it to an AI.
Every step, as a table : Lower bound (3 points)
Best known configuration (constructions), from the Leech, Kallal-Kan-Wang or Cohn-Li records to the AI-assisted constructions of 2025-2026.
| Date | Exact value | Nature | Authors | Source |
|---|---|---|---|---|
| Sep 16, 2026 | 8358 Current record | published | Alexander Kravatskiy | github.com |
| Nov 7, 2024 | 7654 Current record | published | Henry Cohn, Anqi Li | arxiv.org |
| 1967 | 7398 Current record | published | John Leech | doi.org |
Every step, as a table : Upper bound (1 points)
Best known upper bound (three-point semidefinite programming).
| Date | Exact value | Nature | Authors | Source |
|---|---|---|---|---|
| Feb 24, 2022 | 16406 Current record | published | David de Laat, Nando Leijenhorst | arxiv.org |
Kissing number (21)
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