Open Problems in Mathematical General Relativity

The Kerr Problem Archive

A living, community-maintained database of open problems concerning the Kerr spacetime — the rotating black hole solution to Einstein's vacuum equations. Every problem is traceable to a primary source. Status updates as the field moves.

Browse all 50 problems →
50 Total
28 Open
21 Partial
1 Conditional / Solved

Flagship Problems

The three deepest open questions in the archive.

K-001
Full nonlinear stability of subextremal Kerr
partial Exterior Stability
K-101
Strong Cosmic Censorship threshold for Kerr interiors
partial Interior / SCC
K-201
Nonlinear codimension-1 stability of extremal Kerr with horizon hair
open Extremal / Near-Extremal

By Cluster

Exterior Stability
7 open of 14
Interior / SCC
6 open of 12
Extremal / Near-Extremal
7 open of 9
Rigidity / Uniqueness
4 open of 8
Spectral / Scattering
4 open of 7