Pith. sign in

REVIEW 4 major objections 5 minor 82 references

Dynamical Horizons and Black Hole Soft Hair

T0 review · 4 major / 5 minor · reviewed 2026-08-15 · deepseek-v4-flash

Pith's one-line read The paper argues that a black hole that forms and completely evaporates never develops a genuine event horizon; only a two-way traversable dynamical horizon exists, and quasilocal supertranslation charges carry energy and information…

desk verdict A legitimate Brown-York re-derivation of HPS soft hair charges wrapped around an information-preservation scenario whose central mode-convergence assumption is imported from a Vaidya toy model. read the letter →

arxiv 2506.16939 v2 pith:KPA6RZDI submitted 2025-06-20 gr-qc astro-ph.SRhep-th

classification gr-qcastro-ph.SRhep-th MSC 83C5783C4783C3083C45 PACS 04.70.Dy04.60.-m
keywords blackholeinformationparadoxdynamicalhorizonfuturetrappingBrown-YorkquasilocalchargessupertranslationsofthairsuperrotationHawkingradiationevent
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper tries to dissolve the black hole information paradox by changing the horizon itself. It claims that a non-rotating black hole that forms, radiates, and fully evaporates never possesses a genuine one-way event horizon; instead it has a two-way traversable dynamical (future-trapping) horizon. Quasilocal Brown-York charges are derived that coincide, in the large-sphere limit, with the conserved supertranslation and superrotation charges of asymptotically flat gravity, and the paper argues that these charges transport energy and information out of the evaporating hole to null infinity. If the scenario is right, black hole formation and evaporation is a unitary, information-preserving process, and particle creation does not lead to loss of information.

What carries the argument

The load-bearing object is the dynamical (future-trapping) horizon: a hypersurface foliated by marginally trapped surfaces, with one null expansion zero and the other strictly negative, which replaces the global, teleological event horizon as the inner boundary of spacetime. The derivation proceeds through the Brown-York Hamiltonian for a bounded spacetime with a null time-flow vector field; varying the boundary term yields flux integrals that, in the Bondi gauge at null infinity, become the supertranslation and superrotation charges, plus quasilocal corrections to the Bondi mass-loss formula. The mechanism that is claimed to save information is the mode-convergence condition of Appendix B: as the mass tends to zero, $\kappa^{-1}\to 0$ and the horizon modes $g_k$ approach the outgoing Minkowski modes, so the field has the purely outgoing form (52) and the scattering transformation is unitary.

What would settle it

A concrete check is to compute the Bogoliubov coefficients between the early-time and late-time mode bases in the paper's Vaidya mass function (71) beyond leading order. If the particle-production matrix $\beta_{kl}$ does not go to zero as the mass tends to zero, a thermal residue remains and the claimed purification does not occur; conversely, exact vanishing at $M\to 0$ would support the unitary conclusion.

Watch

Extended reading notes

Core claim

The central discovery, stated on the paper's own terms, is that replacing the teleological event horizon by a quasilocal dynamical horizon changes the outcome of black hole evaporation. The paper derives quasilocal Brown-York charges that reduce at infinity to the supertranslation and superrotation charges of the asymptotic symmetry algebra, then uses the semiclassical Einstein equations to extend them to the quantum regime as charges sensitive to backreaction. In the Vaidya-like model of collapse and complete evaporation, the horizon's surface gravity obeys $\kappa^{-1}\to 0$ as the mass tends to zero, so the horizon modes converge to Minkowski modes and the scalar field admits a purely outgoing decomposition with a unitary Bogoliubov transformation. The paper concludes that particle creation effects in nonstationary spacetimes with locally defined dynamical horizons cannot cause information loss at the quantum level.

Load-bearing premise

The entire conclusion rides on an assumption the paper states openly: that at the end of a real semiclassical evaporation the horizon modes behave as in the Vaidya toy model, with $\kappa^{-1}\to 0$ and all modes converging to Minkowski modes so the field becomes purely outgoing; the paper concedes that no solution of the semiclassical Einstein equations for a dynamical black hole is known that would establish this.

Editorial extensions

If this is right

  • If the central claim is correct, black hole formation and complete evaporation is a unitary process: the information in the initial collapsing state reappears, in scrambled form, in the radiation at future null infinity.
  • Hawking radiation from an evaporating dynamical horizon is not thermal at late times; thermal emission with a Planck spectrum is a feature of stationary horizons and disappears once the mass approaches zero.
  • The supertranslation and superrotation charges are not merely asymptotic bookkeeping: their quasilocal versions carry energy and information through the dynamical horizon to infinity, which is the physical channel that prevents information loss.
  • The antipodal matching conditions can be satisfied in the dynamical-horizon setting, removing the horizon charge obstruction that encodes information loss in the standard event-horizon picture.
  • The first law and Smarr formula for stationary black holes emerge as special cases of the same quasilocal Hamiltonian, so the new picture remains consistent with standard black hole thermodynamics.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: if the mechanism is right, information begins leaking during the entire nonstationary phase, not just at the end of evaporation, because the horizon is two-way traversable from the moment it forms; the paper does not quantify how much information exits early versus late.
  • Editorial inference: the same mode-convergence test could be applied to rotating dynamical horizons; angular momentum changes the surface gravity and could slow the $\kappa^{-1}\to 0$ convergence, which would be a concrete way to sharpen or falsify the scenario.
  • Editorial inference: the quasilocal charge flow suggests an observable tie to gravitational memory; the escaping energy flux should leave a memory signal different in angular structure from the classical one, though the paper only gestures at laboratory verification.
  • Editorial inference: standard entropy-curve computations usually fix the Cauchy surface as future null infinity plus the black hole interior; in this picture the traversable horizon changes the surface to future null infinity alone at late times, which would shift where unitarity is tested.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The manuscript pursues two goals. First, within the Brown-York quasilocal framework, it constructs charges Q±_f and Q±_Y in Sections 1.2–1.3 and Appendix A, arguing that in the large-sphere Bondi limit they reduce to the conserved supertranslation and superrotation charges of Hawking, Perry, and Strominger. Second, in Section 2 it replaces the classical stress-energy tensor by a renormalized semiclassical source, defines the semiclassical charges in Eqs. (46)–(48), and then describes an evaporation scenario in which no event horizon forms, the inner boundary is a two-way traversable dynamical horizon, and the scalar-field modes converge to Minkowski modes at late times via Eqs. (49)–(52). From this scenario the paper concludes that particle creation in nonstationary black hole spacetimes with locally defined dynamical horizons cannot cause information loss.

Significance. If the information-preservation claim were established, the paper would offer a concrete mechanism for unitarity in black hole evaporation and would connect it to quasilocal boundary charges. The Brown-York derivation of the HPS supertranslation and superrotation charges is a useful consistency check of known results, and the Vaidya mode analysis in Appendix B is carried out in detail. However, the central claim is not demonstrated: the late-time mode convergence that drives the argument is assumed rather than derived, and the paper itself states that no solutions of the semiclassical Einstein equations exist with which to check the required assumptions. The manuscript contains no machine-checked proofs, numerical simulations, or falsifiable quantitative predictions, and the information-recovery mechanism remains at the level of a heuristic scenario.

major comments (4)
  1. [Sec. 2.3, Eqs. (49)–(52); Appendix B] The information-preservation conclusion is not derived from the semiclassical Einstein equations. The only quantitative basis is the Vaidya toy-model calculation in Appendix B, where the mass function is prescribed by hand in Eq. (71) and the mode functions satisfy Eq. (91); these results are then promoted to a generic evaporating black hole in Eqs. (49)–(50). The manuscript states in Sec. 2.2 that no solutions of the semiclassical Einstein equations describing backreaction in dynamical black hole spacetimes are known and that "it proves impossible to check the validity of the assumptions made by explicit calculations," and it notes in Sec. 2.3 that the semiclassical flux near the horizon is locally negative whereas the Vaidya flux is positive. Consequently, the convergence Eq. (49) and the limit Eq. (50), and therefore the purely outgoing decomposition Eq. (52) with the claimed unitary Bogoliubov transformation, are assumptions rather than consequences of the model. Since Eq. (52) is precisely the statement that no thermal Hawking radiation remains at late times, the conclusion that information is not lost is effectively built in.
  2. [Sec. 2.3, dynamical-horizon scenario; Eqs. (44)–(45)] The assumption that a genuine event horizon never forms is also an input. The paper's argument that event horizons are teleological and therefore absent in an evaporating spacetime is a conceptual preference, not a derived property of a semiclassical solution; no solution of Eq. (37) is exhibited with a timelike, two-way traversable dynamical horizon throughout the evaporation. The ANEC relations (44)–(45), even under the two stated assumptions, only establish non-negativity of some integrated flux expressions; they say nothing about causal two-way traversability of the horizon or about the ability of modes from the trapped region to reach future null infinity. Thus the assertion that there is no causal obstruction for information to escape is unsupported by the equations presented.
  3. [Sec. 2.2, Eq. (48) and following] It is not established that the semiclassical charges Q±_f carry the information that would be lost in the standard Hawking calculation. Equation (48) is an asymptotic integral over I± involving the news and the renormalized stress-energy; the text after Eq. (53) asserts that these charges reach future null infinity and satisfy the antipodal matching conditions, but no computation links the flux of Q±_f to the horizon modes g_k appearing in the decomposition Eq. (30). Without such a link, the statement that soft-hair charges mediate the information transfer is an interpretation rather than a result of the Brown-York derivation.
  4. [Sec. 2.3, text near Eq. (52)] The claim that the limiting Bogoliubov transformation is unitary is not demonstrated. Even if g_m → f_m^{(0)+} and f_m^+ → f_m^{(0)+}, one must show that the matrices α, β, γ, η in Eqs. (32)–(33) define a unitary map between the initial and final Fock spaces; the manuscript only states that "only ingoing and outgoing Minkowskian field modes are being involved." The standard stationary calculation, Eq. (34), exhibits a nonzero β-map, and the dynamical calculation that would make β vanish in the limit is not supplied. This is another place where the key conclusion is assumed.
minor comments (5)
  1. [Throughout] Numerous typographical and grammatical errors should be corrected, including "contiuous," "asssuming," "previosuly," "onclude," "eludicated," and "an an interior part."
  2. [Sec. 1.1] The null expansions Θ and Ξ are defined with Ξ = 0 imposed on a dynamical horizon, but later flux integrals such as Eqs. (40)–(43) treat Ξ as a variable; please clarify whether these are different foliations or a generalized horizon definition.
  3. [Appendix A] The phrase "future past infinity" should be "past null infinity," and the determinant q of the metric q_AB should be defined explicitly in Eqs. (54)–(55).
  4. [Sec. 1.4, Eq. (25)] The Δ-term in Eq. (25) is introduced before it is defined; please provide its explicit expression or a precise reference.
  5. [Eqs. (46)–(47)] There are unmatched parentheses in the displayed equations for the semiclassical charges; the manuscript should be carefully proofread.

Circularity Check

2 steps flagged · score 7.0 of 10

The central no-information-loss conclusion is effectively the imposed late-time Minkowski-mode ansatz (49)-(52), transferred from a Vaidya toy model whose mass function and phase choice are constructed to make the late-time modes Minkowskian.

  1. fitted input called prediction [Sec. 2.3, Eqs. (49)-(52); Summary and Conclusion]
    "The crucial observation now is that the conditions (49−52) are principally strong enough to ensure that the latter is indeed the case, and furthermore to avoid any increase in entropy and thus any associated loss of quantum information along the way. This is because the asymptotic form (52) of the scalar field suggests that radiative modes escaping to future infinity should apparently no longer be thermal in nature at the end of the evaporation process."

    Eq. (52) is obtained by imposing the convergence statements (49)-(50); it is a decomposition of φ into only outgoing Minkowski modes with no horizon modes and no β-coefficients, which is precisely the statement that no thermal Hawking radiation is produced and that the Bogoliubov transformation is unitary. The paper therefore reads the no-information-loss conclusion directly off the imposed mode ansatz rather than deriving it from the semiclassical Einstein equations. It explicitly concedes elsewhere that no semiclassical dynamical black hole solutions are known and that the real semiclassical energy flux near the horizon is locally negative, opposite to the Vaidya input used to justify (49). Thus the central prediction is the input, renamed as a purification mechanism.

  2. self definitional [Appendix B, Eqs. (71), (82)-(91)]
    "The form of these mode solutions clearly shows why it makes sense to consider κ0(v) instead of κ(v) in (72) and to use K0(v) instead of K(v) ... for the definition of the mode functions (73): On the one hand, one has e^{K0(v)}|_{v>v0}=1 due to the fact that K0(v)|_{v<v0}=0 applies by definition"

    The Vaidya toy model is set up so that the late-time result is guaranteed: the mass function (71) vanishes for v>v0, and the integration phase is deliberately chosen as K0 instead of K precisely so that e^{K0}=1 after v0 and the modes (82) become the Minkowski modes (88)/(91). This constructed mode convergence is then imported into Sec. 2.3 as the conditions (49)-(52) that are said to ensure no information loss. The claimed purification is therefore a property of the toy-model ansatz, not a derived property of a semiclassically evaporating black hole.

full rationale

The quasilocal Brown-York and supertranslation/superrotation charge calculations are self-contained and are checked against standard results (Brown-York, Bondi mass-loss, HPS); the author's prior work [53,54] is used for technical machinery but is not the source of the information-loss claim. The circularity is concentrated in the final step: the no-information-loss conclusion is entailed by the late-time mode condition (49)-(52), where a purely outgoing Minkowski decomposition with no horizon modes is equivalent to a β=0 Bogoliubov map, i.e., no particle creation and a unitary S-matrix. Appendix B shows that this condition is baked into the Vaidya toy model by the mass function and by the choice of phase K0; the paper explicitly admits that no solution of the semiclassical Einstein equations for a dynamical black hole is known and that the semiclassical flux near the horizon has the opposite sign to the Vaidya model. The central claim therefore reduces to an imposed ansatz, though the charge formalism and consistency checks retain independent content, so the score is moderate rather than maximal.

Assumptions & free parameters 3 free parameters · 6 assumptions · 1 invented entities

The central information-preservation claim rests on a chain of assumptions: a specific Vaidya mass function with an ad hoc evaporation parameter, identification of its late-time mode limit as physically relevant, and the assumption that no event horizon forms. The free parameters are not fitted to data, but they are chosen to make the desired conclusion emerge, and the semiclassical charges depend on an unspecified renormalization scheme. The only invented entity is the new charge construction itself, which has no independent falsifiable handle.

free parameters (3)
  • Evaporation rate parameter c in Vaidya mass function = unspecified (v0 = 3c/M0^3)
    Appears in Eq. (71); chosen ad hoc to make the mass go to zero smoothly, which drives the claimed late-time mode convergence.
  • Integration constant C in K0(v) = set to zero
    Appendix B sets C = 0 'for the sake of simplicity'; this affects the phase of the mode solutions and hence the claimed purification behavior.
  • Renormalization constants c1, c2, c3 in Θ_ab = unspecified
    Introduced in Eq. (38); the semiclassical charges (46)-(48) depend on an unspecified renormalization scheme, so these constants are free inputs.
assumptions (6)
  • standard math Brown-York Hamiltonian variation formalism with null boundaries yields the quasilocal power functionals (7)-(9)
    The derivation relies on the Brown-York formalism from [16, 23, 24] and the author's previous results [53, 54].
  • domain assumption Semiclassical Einstein equations (37) with renormalized stress tensor
    Used to replace T_ab by ⟨T_ab⟩_ren - Θ_ab in all charge formulas; validity for a dynamical collapsing black hole is assumed, with no explicit solution.
  • domain assumption Existence of preferred Hadamard states ω± with computable renormalized stress tensors near I±
    Section 2.2 states this is assumed; needed to define the semiclassical charges (46)-(48).
  • domain assumption Averaged null energy condition (ANEC) and its angular integral version (44)-(45)
    Used to justify the semiclassical Raychaudhuri integral law (43); the paper admits the additional assumptions (i)-(ii) cannot be checked by explicit calculation.
  • ad hoc to paper Vaidya toy model mode behavior (49)-(52) carries over to a real semiclassically evaporating black hole
    Appendix B derives the mode convergence for the chosen Vaidya mass function; Section 2.3 applies it to the semiclassical scenario without solving the backreaction. This is the load-bearing transfer assumption.
  • ad hoc to paper No genuine event horizon forms; the inner boundary is a two-way traversable dynamical horizon throughout evaporation
    Adopted from [1, 49] and used in Section 2.3 to allow radiation to escape; this is not derived from the semiclassical dynamics.
invented entities (1)
  • Semiclassical Brown-York soft hair charges Q±_f (Eq. 48)
    purpose: Claimed to carry quasilocal energy and information out of the evaporating black hole through the dynamical horizon and to satisfy generalized antipodal matching conditions.
    These are newly defined conserved charges, but the paper provides no independent observable prediction or external benchmark; the charges are constructed from assumptions (renormalized stress tensor, ANEC, Vaidya mode fall-off) that are not independently established.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Dynamical Horizons and Black Hole Soft Hair." pith.science (2026). https://pith.science/paper/KPA6RZDI

@misc{pith2026250616939,
  author       = {Pith},
  title        = {Pith review of: Dynamical Horizons and Black Hole Soft Hair},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/KPA6RZDI}},
  note         = {Machine review of arXiv:2506.16939}
}
read the original abstract

In the present work, quasilocal Brown-York charges are derived that coincide in the large sphere limit with the conserved supertranslation hair and superrotation charges introduced by Hawking, Perry and Strominger in [45, 46]. Given these charges, a general scenario is outlined in which a non-rotating black hole completely evaporates after its collapse due to particle creation effects, whereby a genuine one-way traversable event horizon is never formed, but merely a two-way traversable dynamical (resp. future trapping) horizon. The formation of such a dynamical horizon has the consequence, as is demonstrated, that quasilocal energy transported by the considered charges, and thus information, can continuously escape through the black hole horizon to infinity; a mechanism which, as is argued, could possibly prevent information loss once the black hole formation and evaporation process comes to an end.

Figures

Figures reproduced from arXiv: 2506.16939 by the authors.

Figure 1
Figure 1. A schematic three-dimensional representation of the spacetime mani [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Graphic (a) to the left shows the commonly used Penrose diagram to depict black hole evaporation and the geometric structure of the event hori￾zon throughout the evaporation process, accounting for semiclassical quantum backreaction effects. Graphic (b) on the right, on the other hand, shows a pos￾sible quantum extension of spacetime as proposed by Ashtekar in [1]. Here, the classical singularity is replaced by a tr… view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

82 extracted references · 76 canonical work pages

  1. [1]

    Black hole evaporation: a perspective from loop quantum gravity

    Abhay Ashtekar. Black hole evaporation: a perspective from loop quantum gravity. Universe, 6(2):21, 2020

  2. [2]

    Generic isolated horizons and their applications.Physical Review Letters, 85(17):3564, 2000

    Abhay Ashtekar, Christopher Beetle, Olaf Dreyer, Stephen Fairhurst, Badri Krishnan, Jerzy Lewandowski, and Jacek Wiśniewski. Generic isolated horizons and their applications.Physical Review Letters, 85(17):3564, 2000

  3. [3]

    Isolated hori- zons: a generalization of black hole mechanics

    Abhay Ashtekar, Christopher Beetle, and Stephen Fairhurst. Isolated hori- zons: a generalization of black hole mechanics. Classical and Quantum Gravity, 16(2):L1, 1999

  4. [4]

    Black hole evaporation: A paradigm

    Abhay Ashtekar and Martin Bojowald. Black hole evaporation: A paradigm. Classical and Quantum Gravity, 22(16):3349, 2005

  5. [5]

    Quantum geometry and the schwarzschild singularity.Classical and Quantum Gravity, 23(2):391, 2005

    Abhay Ashtekar and Martin Bojowald. Quantum geometry and the schwarzschild singularity.Classical and Quantum Gravity, 23(2):391, 2005

  6. [6]

    Dynamical horizons and their prop- erties

    Abhay Ashtekar and Badri Krishnan. Dynamical horizons and their prop- erties. Physical Review D, 68(10):104030, 2003

  7. [7]

    Isolated and dynamical horizons and their applications

    Abhay Ashtekar and Badri Krishnan. Isolated and dynamical horizons and their applications. Living Reviews in Relativity, 7:1–91, 2004

  8. [8]

    The energy-momentum tensor of a black hole, or what curves the schwarzschild geometry?Classical and Quantum Gravity, 10(11):2271, 1993

    Herbert Balasin and Herbert Nachbagauer. The energy-momentum tensor of a black hole, or what curves the schwarzschild geometry?Classical and Quantum Gravity, 10(11):2271, 1993

Show all 82 references
  1. [9]

    Distributional energy– momentum tensor of the kerr–newman spacetime family

    Herbert Balasin and Herbert Nachbagauer. Distributional energy– momentum tensor of the kerr–newman spacetime family. Classical and Quantum Gravity, 11(6):1453, 1994

  2. [10]

    Back reaction and the small-mass regime

    Roberto Balbinot. Back reaction and the small-mass regime. Physical Review D, 33(6):1611, 1986. 36

  3. [11]

    Towards the observation of hawking radiation in bose–einstein condensates.International Journal of Modern Physics A, 18(21):3735–3745, 2003

    Carlos Barcelo, Stefano Liberati, and Matt Visser. Towards the observation of hawking radiation in bose–einstein condensates.International Journal of Modern Physics A, 18(21):3735–3745, 2003

  4. [12]

    The four laws of black hole mechanics

    James M Bardeen, Brandon Carter, and Stephen W Hawking. The four laws of black hole mechanics. Communications in mathematical physics, 31:161–170, 1973

  5. [13]

    Hawking radiation from ultrashort laser pulse fila- ments

    Francesco Belgiorno, Sergio L Cacciatori, Matteo Clerici, Vittorio Gorini, Giovanni Ortenzi, Luca Rizzi, <? format?> E Rubino, Vera Giulia Sala, and Daniele Faccio. Hawking radiation from ultrashort laser pulse fila- ments. Physical review letters, 105(20):203901, 2010

  6. [14]

    Quantum fields in curved space

    Nicholas David Birrell and Paul Charles William Davies. Quantum fields in curved space. 1984

  7. [15]

    Gravitational waves in general relativity, vii

    Hermann Bondi, M Gr J Van der Burg, and AWK Metzner. Gravitational waves in general relativity, vii. waves from axi-symmetric isolated system. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 269(1336):21–52, 1962

  8. [16]

    Moving observers, nonorthogonal boundaries, and quasilocal energy.Physical Review D, 59(6):064021, 1999

    IS Booth and RB Mann. Moving observers, nonorthogonal boundaries, and quasilocal energy.Physical Review D, 59(6):064021, 1999

  9. [17]

    Horizon energy and angular momen- tum from a hamiltonian perspective

    Ivan Booth and Stephen Fairhurst. Horizon energy and angular momen- tum from a hamiltonian perspective. Classical and Quantum Gravity, 22(21):4515, 2005

  10. [18]

    The holographic principle

    Raphael Bousso. The holographic principle. Reviews of Modern Physics, 74(3):825, 2002

  11. [19]

    Dynamics and observer dependence of holographic screens.Physical Review D, 95(4):046005, 2017

    Raphael Bousso and Mudassir Moosa. Dynamics and observer dependence of holographic screens.Physical Review D, 95(4):046005, 2017

  12. [20]

    Observable supertranslations.Phys- ical Review D, 96(8):086016, 2017

    Raphael Bousso and Massimo Porrati. Observable supertranslations.Phys- ical Review D, 96(8):086016, 2017

  13. [21]

    Soft hair as a soft wig.Classical and Quantum Gravity, 34(20):204001, 2017

    Raphael Bousso and Massimo Porrati. Soft hair as a soft wig.Classical and Quantum Gravity, 34(20):204001, 2017

  14. [22]

    Action and energy of the gravita- tional field

    J David Brown, SR Lau, and JW York. Action and energy of the gravita- tional field. Annals of Physics, 297(2):175–218, 2002

  15. [23]

    Energy of isolated systems at retarded times as the null limit of quasilocal energy.Physical Review D, 55(4):1977, 1997

    J David Brown, Stephen R Lau, James W York, et al. Energy of isolated systems at retarded times as the null limit of quasilocal energy.Physical Review D, 55(4):1977, 1997

  16. [24]

    Quasilocal energy and con- served charges derived from the gravitational action.Physical Review D, 47(4):1407, 1993

    J David Brown and James W York Jr. Quasilocal energy and con- served charges derived from the gravitational action.Physical Review D, 47(4):1407, 1993. 37

  17. [25]

    Brown-york charges at null boundaries

    Venkatesa Chandrasekaran, Éanna É Flanagan, Ibrahim Shehzad, and Antony J Speranza. Brown-york charges at null boundaries. Journal of High Energy Physics, 2022(1):1–29, 2022

  18. [26]

    Black hole remnants and the information loss paradox.Physics reports, 603:1–45, 2015

    Pisin Chen, Yen Chin Ong, and D-h Yeom. Black hole remnants and the information loss paradox.Physics reports, 603:1–45, 2015

  19. [27]

    Regularization, renormalization, and covariant geodesic point separation

    SM Christensen. Regularization, renormalization, and covariant geodesic point separation. Physical Review D, 17(4):946, 1978

  20. [28]

    Vacuum expectation value of the stress tensor in an arbitrary curved background: The covariant point-separation method

    Steven M Christensen. Vacuum expectation value of the stress tensor in an arbitrary curved background: The covariant point-separation method. Physical Review D, 14(10):2490, 1976

  21. [29]

    Soft hair of dynamical black hole and hawking radiation

    Chong-Sun Chu and Yoji Koyama. Soft hair of dynamical black hole and hawking radiation. Journal of High Energy Physics, 2018(4):1–23, 2018

  22. [30]

    Quantum field theory in curved spacetime.Physics Re- ports, 19(6):295–357, 1975

    Bryce S DeWitt. Quantum field theory in curved spacetime.Physics Re- ports, 19(6):295–357, 1975

  23. [31]

    Carrollian physics at the black hole horizon

    Laura Donnay and Charles Marteau. Carrollian physics at the black hole horizon. Classical and Quantum Gravity, 36(16):165002, 2019

  24. [32]

    Conserved charges of the extended bondi-metzner-sachs algebra

    Éanna É Flanagan and David A Nichols. Conserved charges of the extended bondi-metzner-sachs algebra. Physical Review D, 95(4):044002, 2017

  25. [33]

    Topological cen- sorship

    John L Friedman, Kristin Schleich, and Donald M Witt. Topological cen- sorship. Physical Review Letters, 71(10):1486, 1993

  26. [34]

    Topologicalcensor- ship [phys

    JohnLFriedman, KristinSchleich, andDonaldMWitt. Topologicalcensor- ship [phys. rev. lett. 71, 1486 (1993)].Physical Review Letters, 75(9):1872, 1995

  27. [35]

    Aspects of quantum field theory in curved spacetime

    Stephen A Fulling. Aspects of quantum field theory in curved spacetime. Number 17. Cambridge university press, 1989

  28. [36]

    Singularitystructure of the two-point function in quantum field theory in curved spacetime

    StephenAFulling, MarkSweeny, andRobertMWald. Singularitystructure of the two-point function in quantum field theory in curved spacetime. Communications in Mathematical Physics, 63(3):257–264, 1978

  29. [37]

    Asymptotic structure of space-time

    Robert Geroch. Asymptotic structure of space-time. InAsymptotic struc- ture of space-time, pages 1–105. Springer, 1977

  30. [38]

    Collapsing spherical stars in f (r) gravity

    Rituparno Goswami, Anne Marie Nzioki, Sunil D Maharaj, and Sushant G Ghosh. Collapsing spherical stars in f (r) gravity. Physical Review D, 90(8):084011, 2014

  31. [39]

    A 3+ 1 perspective on null hypersurfaces and isolated horizons

    Eric Gourgoulhon and Jose Luis Jaramillo. A 3+ 1 perspective on null hypersurfaces and isolated horizons. Physics Reports, 423(4-5):159–294, 2006. 38

  32. [40]

    Local quantum physics: Fields, particles, algebras

    Rudolf Haag. Local quantum physics: Fields, particles, algebras. Springer Science & Business Media, 2012

  33. [41]

    Black hole entropy and soft hair.Journal of High Energy Physics, 2018(12):1–19, 2018

    Sasha Haco, Stephen W Hawking, Malcolm J Perry, and Andrew Stro- minger. Black hole entropy and soft hair.Journal of High Energy Physics, 2018(12):1–19, 2018

  34. [42]

    Black hole explosions? Nature, 248(5443):30–31, 1974

    Stephen W Hawking. Black hole explosions? Nature, 248(5443):30–31, 1974

  35. [43]

    Particle creation by black holes.Communications in mathematical physics, 43(3):199–220, 1975

    Stephen W Hawking. Particle creation by black holes.Communications in mathematical physics, 43(3):199–220, 1975

  36. [44]

    Breakdown of predictability in gravitational collapse

    Stephen W Hawking. Breakdown of predictability in gravitational collapse. Physical Review D, 14(10):2460, 1976

  37. [45]

    Soft hair on black holes.Physical Review Letters, 116(23):231301, 2016

    Stephen W Hawking, Malcolm J Perry, and Andrew Strominger. Soft hair on black holes.Physical Review Letters, 116(23):231301, 2016

  38. [46]

    Super- rotation charge and supertranslation hair on black holes.Journal of High Energy Physics, 2017(5):1–33, 2017

    Stephen W Hawking, Malcolm J Perry, and Andrew Strominger. Super- rotation charge and supertranslation hair on black holes.Journal of High Energy Physics, 2017(5):1–33, 2017

  39. [47]

    The unpredictability of quantum gravity.Com- munications in Mathematical Physics, 87:395–415, 1982

    Stephen William Hawking. The unpredictability of quantum gravity.Com- munications in Mathematical Physics, 87:395–415, 1982

  40. [48]

    General laws of black-hole dynamics.Physical Review D, 49(12):6467, 1994

    Sean A Hayward. General laws of black-hole dynamics.Physical Review D, 49(12):6467, 1994

  41. [49]

    The disinformation problem for black holes (conference version)

    Sean A Hayward. The disinformation problem for black holes (conference version). arXiv preprint gr-qc/0504037, 2005

  42. [50]

    The scattering matrix approach for the quantum black hole: An overview

    G’t Hooft. The scattering matrix approach for the quantum black hole: An overview. International Journal of Modern Physics A, 11(26):4623–4688, 1996

  43. [51]

    Junction conditions and local spacetimes in general relativ- ity

    Albert Huber. Junction conditions and local spacetimes in general relativ- ity. The European Physical Journal C, 80:1–19, 2020

  44. [52]

    Hidden killing fields, geometric symmetries and black hole mergers

    Albert Huber. Hidden killing fields, geometric symmetries and black hole mergers. Annals of Physics, 434:168650, 2021

  45. [53]

    Remark on the quasilocal calculation of tidal heating: Energy transfer through the quasilocal surface

    Albert Huber. Remark on the quasilocal calculation of tidal heating: Energy transfer through the quasilocal surface. Physical Review D, 105(2):024011, 2022

  46. [54]

    Quasilocal corrections to Bondi s mass-loss formula and dynamical horizons

    Albert Huber. Quasilocal corrections to Bondi s mass-loss formula and dynamical horizons. Physical Review D, 108(8):084056, 2023

  47. [55]

    Stress tensor on null boundaries

    Ghadir Jafari. Stress tensor on null boundaries. Physical Review D, 99(10):104035, 2019. 39

  48. [56]

    Hawking effect in vaidya- bonner space-time

    Zhu Jianyang, Zhang Jianhua, and Zhao Zheng. Hawking effect in vaidya- bonner space-time. International Journal of Theoretical Physics, 33:2137– 2145, 1994

  49. [57]

    Conserved energy flux for the spherically symmetric system and the backreaction problem in the black hole evaporation.Progress of Theoretical Physics, 63(4):1217–1228, 1980

    Hideo Kodama. Conserved energy flux for the spherically symmetric system and the backreaction problem in the black hole evaporation.Progress of Theoretical Physics, 63(4):1217–1228, 1980

  50. [58]

    Tortoise coordinate trans- formation on apparent horizon of a dynamical black hole

    Xianming Liu, Zheng Zhao, and Wenbiao Liu. Tortoise coordinate trans- formation on apparent horizon of a dynamical black hole. InInternational Journal of Modern Physics: Conference Series, volume 12, pages 358–367. World Scientific, 2012

  51. [59]

    Bondi-sachs formalism.Scholarpe- dia, 11(12):33528, 2016

    Thomas Mädler and Jeffrey Winicour. Bondi-sachs formalism.Scholarpe- dia, 11(12):33528, 2016

  52. [60]

    Eternal black holes in anti-de sitter

    Juan Maldacena. Eternal black holes in anti-de sitter. Journal of High Energy Physics, 2003(04):021, 2003

  53. [61]

    The information paradox: a pedagogical introduction

    Samir D Mathur. The information paradox: a pedagogical introduction. Classical and Quantum Gravity, 26(22):224001, 2009

  54. [62]

    What exactly is the information paradox? InPhysics of Black Holes: A Guided Tour, pages 3–48

    Samir D Mathur. What exactly is the information paradox? InPhysics of Black Holes: A Guided Tour, pages 3–48. Springer, 2009

  55. [63]

    Dressed hard states and black hole soft hair.Physical review letters, 117(21):211301, 2016

    Mehrdad Mirbabayi and Massimo Porrati. Dressed hard states and black hole soft hair.Physical review letters, 117(21):211301, 2016

  56. [64]

    Wormholes, time machines, and the weak energy condition

    Michael S Morris, Kip S Thorne, and Ulvi Yurtsever. Wormholes, time machines, and the weak energy condition. Physical Review Letters, 61(13):1446, 1988

  57. [65]

    Introduction to quantum effects in gravity

    ViatcheslavMukhanovandSergeiWinitzki. Introduction to quantum effects in gravity. Cambridge university press, 2007

  58. [66]

    Observation of thermal hawking radiation and its temperature in an analogue black hole.Nature, 569(7758):688–691, 2019

    Juan Ramón Muñoz de Nova, Katrine Golubkov, Victor I Kolobov, and Jeff Steinhauer. Observation of thermal hawking radiation and its temperature in an analogue black hole.Nature, 569(7758):688–691, 2019

  59. [67]

    New gravitational memories

    Sabrina Pasterski, Andrew Strominger, and Alexander Zhiboedov. New gravitational memories. Journal of High Energy Physics, 2016(12):1–15, 2016

  60. [68]

    Cambridge University Press, 1984

    Roger Penrose and Wolfgang Rindler.Spinors and space-time: Volume 2, Spinor and twistor methods in space-time geometry, volume 2. Cambridge University Press, 1984

  61. [69]

    Hawking radiation in an electro- magnetic waveguide? Physical review letters, 95(3):031301, 2005

    Ralf Schützhold and William G Unruh. Hawking radiation in an electro- magnetic waveguide? Physical review letters, 95(3):031301, 2005. 40

  62. [70]

    Observation of quantum hawking radiation and its entan- glement in an analogue black hole.Nature Physics, 12(10):959–965, 2016

    Jeff Steinhauer. Observation of quantum hawking radiation and its entan- glement in an analogue black hole.Nature Physics, 12(10):959–965, 2016

  63. [71]

    Microscopic origin of the bekenstein-hawking entropy.Physics Letters B, 379(1-4):99–104, 1996

    Andrew Strominger and Cumrun Vafa. Microscopic origin of the bekenstein-hawking entropy.Physics Letters B, 379(1-4):99–104, 1996

  64. [72]

    Gravitational memory, bms supertranslations and soft theorems

    Andrew Strominger and Alexander Zhiboedov. Gravitational memory, bms supertranslations and soft theorems. Journal of High Energy Physics, 2016(1):1–15, 2016

  65. [73]

    Black holes and the information paradox

    Leonard Susskind. Black holes and the information paradox. Scientific American, 276(4):52–57, 1997

  66. [74]

    Twenty years of debate with stephen.The Future of Theoretical Physics, pages 330–47, 2003

    Leonard Susskind. Twenty years of debate with stephen.The Future of Theoretical Physics, pages 330–47, 2003

  67. [75]

    The back reaction effect in particle creation in curved spacetime

    Robert M Wald. The back reaction effect in particle creation in curved spacetime. Communications in Mathematical Physics, 54(1):1–19, 1977

  68. [76]

    University of Chicago press, 1994

    Robert M Wald.Quantum field theory in curved spacetime and black hole thermodynamics. University of Chicago press, 1994

  69. [77]

    The thermodynamics of black holes

    Robert M Wald. The thermodynamics of black holes. Living reviews in relativity, 4:1–44, 2001

  70. [78]

    Proving the achronal averaged null energy condition from the generalized second law.Physical Review D, 81(2):024038, 2010

    Aron C Wall. Proving the achronal averaged null energy condition from the generalized second law.Physical Review D, 81(2):024038, 2010

  71. [79]

    Silke Weinfurtner, Edmund W Tedford, Matthew CJ Penrice, William G Unruh, and Gregory A Lawrence. Classical aspects of hawking radiation verified in analogue gravity experiment.Analogue gravity phenomenology: Analogue spacetimes and horizons, from theory to experiment, pages 1...

  72. [80]

    Quantum theory of gravity: Essays in honor of the 60th birthday of bryce s.Dewitt, ed, Christensen, SM (Adam Hilger Ltd., Bristol), 1984

    JW York. Quantum theory of gravity: Essays in honor of the 60th birthday of bryce s.Dewitt, ed, Christensen, SM (Adam Hilger Ltd., Bristol), 1984

  73. [81]

    A new method dealing with hawking effects of evaporating black holes

    Zhao Zheng and Dai Xianxin. A new method dealing with hawking effects of evaporating black holes. Modern Physics Letters A, 7(20):1771–1778, 1992

  74. [82]

    Naked singularity formation in gravity

    AH Ziaie, K Atazadeh, and SMM Rasouli. Naked singularity formation in gravity. General Relativity and Gravitation, 43(11):2943–2963, 2011. 41

Pith tools

Reviewed August 15, 2026 · model on record in the stance chip above.