Pith. sign in

REVIEW 4 cited by

Creases, corners and caustics: properties of non-smooth structures on black hole horizons

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2303.15512 v2 pith:74LO25YJ submitted 2023-03-27 gr-qc hep-th

Creases, corners and caustics: properties of non-smooth structures on black hole horizons

classification gr-qc hep-th
keywords horizoncreasesholeblackcausticnon-smoothcornersentropy
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

The event horizon of a dynamical black hole is generically a non-smooth hypersurface. We classify the types of non-smooth structure that can arise on a horizon that is smooth at late time. The classification includes creases, corners and caustic points. We prove that creases and corners form spacelike submanifolds of dimension $2,1$ and that caustic points form a set of dimension at most $1$. We classify "perestroikas" of these structures, in which they undergo a qualitative change at an instant of time. A crease perestroika gives an exact local description of the event horizon near the "instant of merger" of a generic black hole merger. Other crease perestroikas describe horizon nucleation or collapse of a hole in a toroidal horizon. Caustic perestroikas, in which a pair of caustic points either nucleate or annihilate, provide a mechanism for creases to decay. We argue that properties of quantum entanglement entropy suggest that creases might contribute to black hole entropy. We explain that a "Gauss-Bonnet" term in the entropy is non-topological on a non-smooth horizon, which invalidates previous arguments against such a term.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Quantization of Gravity on Null Hypersurfaces

    hep-th 2026-07 conditional novelty 7.0

    An operator-algebraic quantization of the characteristic initial-value problem yields a candidate on-shell algebra for a gravitational subregion bounded by two null hypersurfaces.

  2. Thermodynamics of dynamical black holes beyond perturbation theory

    gr-qc 2026-03 accept novelty 7.0

    The authors derive non-perturbative first and second laws for dynamical black holes, identifying entropy with the area of local marginally trapped surfaces rather than the global event horizon.

  3. Thermodynamics of dynamical black holes beyond perturbation theory

    gr-qc 2026-03 unverdicted novelty 6.0

    Quasi-local dynamical horizons admit a first law for finite, far-from-equilibrium processes and a quantitative second law tying area growth to energy fluxes, so black-hole entropy is the area of marginally trapped surfaces.

  4. Semi-classical spacetime thermodynamics

    hep-th 2025-09 unverdicted novelty 5.0

    Derives semi-classical gravity from thermodynamics of stretched light cones in 2D dilaton gravity with explicit conformal anomaly backreaction and shows equations of motion follow from dynamical Wald entropy in Brans-...