About

This site tracks open problems in the mathematics and physics of the Kerr spacetime — the exact rotating black hole solution to Einstein's vacuum field equations, discovered by Roy Kerr in 1963.

The database was started in April 2026. Every problem statement is traced to a primary source: a paper, a survey, or a recorded lecture by a researcher working in the field. This site curates and organises — it does not adjudicate.

The status labels mean:

• open No theorem in the stated form is currently known.
• partial Important special cases, reductions, or adjacent results exist.
• conditional The problem is reduced to a specific missing input.
• solved A complete theorem in the stated form is known.

Difficulty ratings (1–5) are heuristic estimates based on the current state of the field, not permanent verdicts. A problem rated 5 today may become 3 tomorrow.

Contributing

All problems are stored as YAML files in the GitHub repository. To propose a correction, a new problem, or a status update, open a pull request. See CONTRIBUTING.md for the full guide.

If you have worked on one of these problems and believe the statement or status is wrong, please open an issue or email admin@kerrproblems.com. Accuracy is the site's only claim to authority.