Problems Extremal / Near-Extremal K-622
K-622

Prove uniform (in kappa) energy/decay estimates for near-extremal Kerr approaching kappa to 0.

Open Classical frontier Open in literature Mostly scoped Extremal / Near-Extremal Pure math FV: low
Near-Kerr (vacuum) Asymptotically flat Vacuum Full Einstein Near-extremalExtremalExterior

Summary

Prove uniform (in kappa) energy/decay estimates for near-extremal Kerr approaching kappa to 0.

Why this matters

Key missing uniformity for near-extremal analysis.

Exact scope

Background / setting
asymptotically flat general relativity context; see family and coupling tags for matter model.
Equation type
PDE level: full-einstein.
Linearity
linearized
Regularity
Smooth / Sobolev hypotheses must be stated precisely in any final theorem; this provisional entry does not fix minimal regularity.
Parameter regime
Extremal or near-extremal Kerr-type parameters; quantify smallness of $|1-|a|/M|$ or surface gravity $κ$ in any claim.
Asymptotics
asymptotically flat
Gauge / formulation
State gauge/fixing class compatible with cited stability or interior programs (e.g. generalized harmonic, double-null interior charts).

Status explanation

Theorem status follows literature as summarized in known results and references (not upgraded without verified solution pointers).

Problem statement

Prove uniform (in kappa) energy/decay estimates for near-extremal Kerr approaching kappa to 0.

What is already known

  • Aretakis instability and conserved charges on extremal horizons are established for scalar test fields; spin-2 and nonlinear extremal dynamics are much less complete.
    Regime: Extremal horizons; often linear scalar.
    Shows qualitative difference from subextremal decay.
  • Subextremal nonlinear Kerr stability is known for small $|a|/M$; uniformity as $|a|\to M$ is not a corollary.
    Regime: Nonlinear vacuum, restricted subextremal window.
    Separates near-extremal uniformity from existing subextremal theorems.
  • Near-horizon NHEK limits capture extremal mode structure but matching to global Kerr is an open PDE bridge.
    Regime: Near-horizon scaling limits.
    Clarifies what NHEK analyses do and do not imply globally.

Progress summary: Context: Key missing uniformity for near-extremal analysis.

What remains open

Prove uniform (in kappa) energy/decay estimates for near-extremal Kerr approaching kappa to 0.

Mathematical prerequisites

Match hypotheses to primary sources cited on this page; state minimal regularity, gauge class, and parameter windows in any claimed theorem.

Completion criteria

Prove a theorem or give a rigorous counterexample that matches the scoped statement under explicitly listed hypotheses.

Implications if solved

Impact depends on the solved formulation; sharpen once the statement is pinned to a literature-compatible theorem.

Formal verification suitability

FV: low

Global PDE or phenomenological target; lemma-level formalization may be possible after scoping.

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-620 — Establish a rigorous nonlinear theory for extremal Kerr dynamics incorporating Aretakis charges.
  • K-656 — Prove decay/growth dichotomy for extremal Kerr perturbations with explicit identification of conserved charges.
  • K-657 — Prove nonlinear evolution of near-horizon conserved quantities in extremal Kerr produces curvature singularity (or not).
  • K-691 — Prove that event-horizon redshift estimates remain valid for near-extremal Kerr with uniform constants away from kappa=0.
  • K-621 — Prove a definitive linear stability/instability dichotomy for extremal Kerr spin-2 with sharp norms.

Editorial / maintainer notes

Source manifest: N-022 (expansion_from_manifest.tsv). Numeric footnotes from the original table are not reproduced in this repository.


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