Problems Rigidity / Uniqueness K-308
K-308

Rigidity and uniqueness with matter: full Kerr–Newman regime

Partial progress Classical frontier Open in literature Mostly scoped Rigidity / Uniqueness Pure math FV: medium
Kerr–Newman Asymptotically flat Matter-coupled Stationary reductionEinstein–Maxwell Stationary

Summary

Complete stationary uniqueness/rigidity for Kerr–Newman without smallness caveats; partial linearized exterior progress exists (cf. K-008), but global stationary uniqueness in the smooth category remains incomplete.

Why this matters

Charged rotating solutions are physically central; their rigidity theory lags the vacuum Carter–Robinson picture in generality.

Exact scope

Background / setting
Stationary Einstein–Maxwell, asymptotically flat, subextremal Kerr–Newman as target family.
Equation type
Stationary coupled elliptic-type reduction; EM gauge issues included.
Linearity
Stationary nonlinear coupled system.
Regularity
Smooth / high Sobolev as in rigidity programs.
Parameter regime
Full subextremal $(M,a,Q)$ range is the goal; partial results may cover restricted sets.
Asymptotics
Asymptotically flat.
Gauge / formulation
Lorenz / generalized wave-map gauges as in linearized stability literature.

Status explanation

Partial: coupled linearized results exist; full stationary uniqueness without smallness remains open.

Problem statement

Prove the full stationary uniqueness and perturbative rigidity theory for asymptotically flat Einstein–Maxwell black-hole solutions in the subextremal Kerr–Newman class—without small-charge or slow-rotation restrictions once the sharp theorem is available.

What is already known

  • Linearized decay/stability for weakly charged, slowly rotating Kerr–Newman (partial exterior linear result).
    Regime: Linearized Einstein–Maxwell as in arXiv:2301.08557.
    Partial progress on dynamics; stationary uniqueness is a distinct stationary elliptic problem.

Progress summary: Vacuum rigidity is more complete; Einstein–Maxwell stationary uniqueness in full parameters and partial linearized stability are both active areas.

What remains open

Global smooth stationary uniqueness/rigidity matching vacuum rigidity strength across parameters.

Mathematical prerequisites

Einstein–Maxwell stationary reduction; coupled invariant tensors; horizon regularity; unique continuation.

Completion criteria

Sharp hypothesis theorem classifying stationary solutions as Kerr–Newman in the smooth category.

Implications if solved

Completes charged rotating rigidity parallel to vacuum Kerr uniqueness.

Formal verification suitability

FV: medium

Some subquestions may formalize before the full statement.

See Formal verification for how this database uses these labels.

References

Related by shared tags

Heuristic matches on family, cluster, equation level, asymptotics, and relevance.

  • K-687 — Prove a black-hole uniqueness theorem for near Kerr-Newman-de Sitter without analyticity in smooth category.
  • K-501 — Quantitative Mars–Simon tensor gap for near-Kerr stationary vacuum data
  • K-502 — Horizon-data rigidity and effective reconstruction of Kerr parameters
  • K-503 — Algebraic uniqueness of quadratic symmetry operators commuting with $\Box_g$ on exact Kerr ($\mathcal{D}_{\le 2}$ class)

Last updated: 2026-04-06 · Last verified (editorial): 2026-04-06 (editorial-refactor) · Edit on GitHub →