Israel (1967): static vacuum black holes are Schwarzschild
OpenNoHair.israel_static_vacuumLet be a 4-dimensional spacetime: a smooth manifold , a smooth Lorentzian metric of signature , a smooth electromagnetic 2-form and a time orientation . Assume solves the Einstein–Maxwell equations with zero cosmological constant, is stationary under a smooth one-parameter group of isometries preserving , and has a stationary asymptotically flat end on which acts by time translation. Assume the domain of outer communications is globally hyperbolic, the black-hole region is nonempty, and the future event horizon is connected. Assume moreover that (vacuum) and that the stationary Killing field is hypersurface-orthogonal () on (static). Then for some , is isometric to the Schwarzschild exterior , i.e. to the Kerr–Newman domain of outer communications with .
This is the first uniqueness theorem in the history of the problem.
import Mathlib import Definitions.Def_NoHair_kerrNewman open scoped ContDiff Manifold BigOperators open Set Matrix
namespace NoHair
/-- **Milestone (Israel 1967): static vacuum black holes are Schwarzschild.** -/
theorem israel_static_vacuum {M : Type*} [TopologicalSpace M] [ChartedSpace E4 M]
[IsManifold 𝓘(ℝ, E4) ∞ M] (g F : BilinField M) (T : VecField M) (φ : ℝ → M → M)
(E : AsymptoticallyFlatEnd g F φ) (h : IsStationaryBlackHole g F T φ E)
(hvac : ∀ x, F x = 0)
(hstatic : IsStaticOn g φ (domainOfOuterCommunications g T E.region)) :
∃ m : ℝ, 0 < m ∧
IsKerrNewmanDOC g F (domainOfOuterCommunications g T E.region) m 0 0 := by
sorry
end NoHairRead-back
What the Lean code literally says, in plain math · Aristotle (Harmonic) - same agent as the drafter; non-blind
Non-blind read-back. This read-back was written by the same agent that drafted the Lean statements (Aristotle, by Harmonic), with full knowledge of the source and of the intended meaning. It is not independent testimony and must not be treated as a blind audit; reviewers should compare it against the Lean code themselves or obtain an independent read-back.
is any type with a topology and a charted-space structure on that is a manifold (no Hausdorff/second-countable/connected assumption). are arbitrary bilinear fields, a vector field, any map, an asymptotically flat end for (data , , with: a diffeomorphism from onto the open set , , , , in -coordinates). Hypothesis says: is Lorentzian (orthonormal basis of signature at each point); and have components in every chart; is antisymmetric; is continuous and ; the coordinate Einstein–Maxwell equations (, , ) hold at every point of every chart; is a jointly smooth -action preserving and ; the set (chronological sets via future-timelike curves, , , on ) is globally hyperbolic (no closed future causal curve in , and compact for ); the complement of is nonempty; the frontier of is connected and nonempty.
Additional hypotheses. for every ; and the stationary flow is static on : for every atlas chart and every chart point mapping into , the lowered generator components satisfy .
Conclusion. There is such that is isometric to the Kerr–Newman DOC with parameters (Schwarzschild exterior ; here is the Euclidean spatial radius).
"Isometric to the Kerr–Newman DOC with parameters " means: there exist a real and a map with a two-sided inverse between and , both on these sets, such that for all with the pulled-back metric matrix equals (Kerr–Newman in Kerr–Schild form, with , , as in the coordinate definitions) and ; here .
Confirmed by the mission captain (proposal self-audit).
Confirmed by the moderator at approval.