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Classification of $\Lambda \neq 0$-vacuum algebraically special spacetimes with conformally flat $\mathscr I$ from Weyl tensor expansion

T0 review · 2 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Four-dimensional Λ-vacuum spacetimes that are algebraically special with a locally conformally flat null infinity coincide with the Kerr–de Sitter-like class; the paper's main theorem pins their electric Weyl data at infinity to a single…

desk verdict Strong, reusable asymptotic toolbox and a plausible new characterization of the Kerr-de Sitter-like class, but the λ>0 branch of the main theorem rests on a WAND-extendability lemma that does not cover black-hole spacetimes. read the letter →

arxiv 2507.21292 v1 pith:IQN5MXDR submitted 2025-07-28 gr-qc math-phmath.MP

classification gr-qcmath-phmath.MP MSC 83C3083C20 PACS 04.20.-q04.20.Ha04.20.Jb
keywords WeyltensoralgebraicallyspecialspacetimesKerr–deSitterspacetimeconformallyflatnullinfinityFefferman–Grahamexpansioncosmologicalconstantasymptoticinitialdataalgebraicclassificationofthe
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

Four-dimensional vacuum spacetimes with non-zero cosmological constant that are algebraically special and have a locally conformally flat null infinity are claimed to be exactly the Kerr–de Sitter-like class. The paper reaches the claim by developing a covariant decomposition of Weyl-type tensors with respect to a non-null vector, which turns the Gauss, Codazzi and Ricci identities into identities for the Weyl tensor whose terms live entirely on the hypersurfaces orthogonal to that vector. Paired with the Fefferman–Graham expansion of the metric at null infinity, these identities deliver the first two orders of the Weyl tensor's fall-off, and the algebraic type-II condition becomes two intrinsic equations at the boundary. When the boundary metric is locally conformally flat, those equations integrate to a single algebraic form for the electric part of the Weyl tensor at $\mathscr I$, namely $W^\perp_{\alpha\beta} = \frac{\kappa}{|\xi|^5_\gamma}\left(\xi_\alpha\xi_\beta + \frac{\epsilon|\xi|^2_\gamma}{3}\gamma_{\alpha\beta}\right)$ with $\kappa\in\{0,\pm1\}$ and $\xi$ a conformal Killing vector of the boundary metric — precisely the data that define the Kerr–de Sitter-like class. Since metrics of that class are themselves algebraically special, the paper concludes that the two families coincide, giving a local geometric characterization of a family that contains Kerr–de Sitter.

What carries the argument

The engine is a covariant decomposition of any Riemann-type or Weyl-type tensor with respect to a unit non-null vector $u$, $T = T^{\parallel u} + \epsilon\, u \circledast T^{\perp\parallel} + T^{\perp} \mathbin{?} \eta$ (Lemma 1), built so that the Weyl tensor's components relate to the intrinsic geometry of the hypersurfaces orthogonal to $u$ through Gauss, Codazzi and Ricci-type identities (Proposition 2). Near null infinity, $u$ is taken to be the normalized gradient of the conformal factor, and the identities express the Weyl tensor entirely in terms of the boundary metric $\gamma$ and its Fefferman–Graham coefficients. In four dimensions the tangential part collapses to $Weyl^{\parallel}_g = -\epsilon\, Weyl^{\perp}_g \mathbin{?} \gamma$ (here $?$ denotes the Kulkarni–Nomizu product), so the whole conformal curvature near $\mathscr I$ is governed by the electric part $W^{\perp}$. Feeding the first two orders of the Fefferman–Graham expansion into the algebraic type-II condition yields the boundary system (79)–(80); when $\gamma$ is locally conformally flat the Cotton tensor of $\gamma$ vanishes, and the system integrates to the single form (89) with $\xi = f y$ satisfying the conformal Killing equation of $\gamma$.

What would settle it

Two concrete checks would settle the claim. First, follow the ingoing principal null direction of the Kerr–de Sitter metric backward from the horizon: if a future-inextendible null geodesic with that tangent fails to intersect $\mathscr I^+$ exactly once, the hypothesis behind the $\lambda>0$ extension lemma fails on exactly the spacetimes the theorem targets, and the classification would need a stricter assumption. Second, compute the electric Weyl part at $\mathscr I$ for a known Kerr–de Sitter-like metric, for instance from its Kerr–Schild form, and verify that it reproduces (89) with $\xi$ a conformal Killing vector; any algebraically special $\Lambda$-vacuum spacetime with conformally flat $\mathscr I$ whose $W^\perp$ at $\mathscr I$ violates this form would refute the classification.

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Extended reading notes

Core claim

On the paper's own terms the result is Theorem 2: let $(\widetilde{M},\tilde g)$ be a four-dimensional Einstein manifold with $\lambda\neq 0$ admitting a locally conformally flat null infinity $\mathscr I$ and whose Weyl tensor has algebraic type at least II with a geodesic multiple WAND (Weyl Aligned Null Direction) $k$, with $k$ assumed to extend transversally to $\mathscr I$ when $\lambda<0$. Then the electric part of the Weyl tensor at $\mathscr I$ takes the form $W^\perp_{\alpha\beta} = \frac{\kappa}{|\xi|^5_\gamma}\left(\xi_\alpha\xi_\beta + \frac{\epsilon|\xi|^2_\gamma}{3}\gamma_{\alpha\beta}\right)$ with $\kappa\in\{0,\pm1\}$ and $\xi$ a conformal Killing vector of the boundary metric $\gamma$. Because this is exactly the asymptotic-data form that defines the Kerr–de Sitter-like class with conformally flat $\mathscr I$, and because that class is known to consist of algebraically special (type at least II) metrics, the paper concludes that the two families coincide: four-dimensional algebraically special $\Lambda$-vacuum spacetimes with conformally flat $\mathscr I$ are exactly the Kerr–de Sitter-like class.

Load-bearing premise

The load-bearing premise is that the multiple WAND $k$, the privileged null direction singled out by the algebraic condition, reaches null infinity and meets it transversally: this is assumed outright for $\lambda<0$, while for $\lambda>0$ it is derived from a global-hyperbolicity argument whose key property — that every future-inextendible null geodesic from the interior hits $\mathscr I^+$ exactly once — fails when an event horizon is present and is open for the Kerr–de Sitter-like metrics the theorem is meant to classify.

Editorial extensions

If this is right

  • For $\lambda>0$, where $(\gamma, W^\perp)$ are the free asymptotic data of the Cauchy problem at $\mathscr I$, Theorem 2 says the data of every algebraically special spacetime with conformally flat $\mathscr I$ are exhausted, up to the constants $(\kappa, f, \xi)$, by a single conformal Killing vector field of the boundary metric.
  • The case $W^\perp=0$ yields data locally diffeomorphic to de Sitter near $\mathscr I$, so de Sitter appears in the classified family as the trivial member.
  • The equivalence connects three previously separate descriptions of the same family: data of the form (89), the alignment of the bulk Weyl tensor with a Killing vector plus conformally flat $\mathscr I$, and Kerr–Schild metrics sharing null infinity with a de Sitter background.
  • The general expansion of the Weyl tensor near $\mathscr I$ is worked out in all dimensions and for both signs of $\Lambda$, with the first terms given explicitly; the paper announces that the same machinery yields the higher-dimensional analogue of the classification.
  • The boundary system (79)–(80) gives an integration recipe around any locally conformally flat $\gamma$: solve (80) for the pair $(f,y)$, form $W^\perp$ through (79), and read off admissible asymptotic data for an algebraically special spacetime; whether satisfying the system asymptotically is sufficient for type II in a neighbourhood of $\mathscr I$ is left open.

Reading between the lines

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

  • The transversal-extension hypothesis could probably be traded for a horizon-free (asymptotic simplicity) condition, which would split the family into spacetimes whose multiple WAND reaches $\mathscr I$ and horizon-bound spacetimes that escape the theorem's assumptions.
  • The collapse to a single field is special to four dimensions, where conformal flatness is the only curvature condition on the three-dimensional boundary; in higher dimensions the boundary Weyl tensor enters independently, so the expected classification will be a family of data sets rather than one algebraic form.
  • If the equivalence holds, 'is this spacetime Kerr–de Sitter-like?' becomes a local question answerable at infinity — check algebraic type II and the vanishing of the boundary Cotton tensor — which is much cheaper than the global uniqueness arguments used elsewhere.
  • The computed fall-offs imply that the information carried by the electric part at $\mathscr I$ is dimension-dependent — $O(\Omega)$ in four dimensions, $O(\Omega^2)$ in higher dimensions, with a $\Omega^2\log\Omega$ anomaly in five — which suggests that proposals for gravitational radiation based on $W^\perp$ transfer across dimensions only with care.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 4 minor

Summary. The paper develops a covariant algebraic decomposition of Riemann-type and Weyl-type tensors with respect to a non-null vector, derives Gauss, Codazzi, and Ricci-type identities for the Weyl tensor, and combines these with Fefferman-Graham expansions to compute the leading and subleading fall-off of the Weyl tensor components near conformal infinity in Lambda-vacuum spacetimes. In four dimensions, the authors specialize the algebraic type II (multiple WAND) conditions and obtain two asymptotic equations, (79) and (80), relating the boundary metric, the rescaled electric Weyl tensor W^⊥, and an auxiliary unit vector y. For locally conformally flat I they integrate these equations and conclude that W^⊥ has the form (89) with ξ a conformal Killing vector of the boundary metric. The paper then invokes the existing classification of Mars, Paetz, Senovilla, and Simon to argue that this coincides with the Kerr-de Sitter-like class with conformally flat I.

Significance. If the main theorem is established, the paper provides a clean geometric characterization of the Kerr-de Sitter-like class in four dimensions and demonstrates that local conformal flatness of I is a robust criterion for algebraic specialness. The algebraic decomposition and the explicit asymptotic formulas (60)-(62) are useful and appear to be derived carefully; the honesty about the open sufficiency question for equations (79)-(80) is commendable. However, the lambda>0 branch of Theorem 2 rests on Lemma 6, whose proof is not valid for black-hole spacetimes of the intended class, and the 'exact match' statement in the abstract is stronger than what is proven for lambda<0. With an explicit extendability hypothesis and a scoped statement of the classification, the paper would be a solid contribution.

major comments (2)
  1. [Section 5, Lemma 6 and Theorem 2] The proof of Lemma 6 restricts to M = D^-(I^+) and uses the property that every future-inextendible causal geodesic starting in M\I^+ intersects I^+ exactly once. This is a property of the chosen domain of dependence, not of the vector field k. In spacetimes with horizons in the intended class, such as Kerr-de Sitter, the future-directed ingoing repeated principal null geodesic from points arbitrarily close to I^+ crosses the event horizon and never reaches I^+; those points are not in D^-(I^+), so D^-(I^+) contains no collar neighbourhood of I^+. Consequently the map phi in Lemma 6 need not cover a neighbourhood of I^+, and the lemma does not prove that an arbitrary geodesic multiple WAND k extends to I for lambda>0. Since Theorem 2 is stated for an arbitrary such k with no lambda>0 extendability assumption, its lambda>0 branch is not established as written. The theorem should either assume transversal extendability of k for both signs of lambda, or explicitly allow the choice of a multiple WAND whose integral curves are future-complete to I^+, and the subsequent classification statement should be scoped accordingly.
  2. [Abstract and Section 5.1] The abstract and the introduction claim that four-dimensional algebraically special spacetimes with locally conformally flat I 'match exactly' the Kerr-de Sitter-like class. What the body proves is the necessary statement of Theorem 2 for lambda != 0 (with the extendability caveat above) and, for lambda>0, the converse by invoking the classification of [38] and the fact that Kerr-Schild metrics are of algebraic type at least II. For lambda<0 no converse is proved: the paper does not show that every set of data of the form (89), with xi a boundary conformal Killing vector, arises from an algebraically special bulk spacetime, nor that the Kerr-de Sitter-like class with conformally flat I exhausts those data in the negative-lambda case. The text after Eq. (80) itself states that sufficiency of (79)-(80) for the bulk type II property is open. The 'exact match' claim should therefore be restricted to lambda>0, or the missing converse for lambda<0 should be proved.
minor comments (4)
  1. [Section 5, notation around Eq. (59) and Appendix A] The symbol W^⊥ is used both for the rescaled leading coefficient Omega^{-1} Weyl^⊥|_I in Eq. (59) and for the limit L_{\partial\Omega} W^⊥|_I in Eq. (90). The two are consistent, but the overloaded notation should be flagged explicitly to avoid confusion.
  2. [Throughout] There are numerous typographical errors and inconsistencies in names (for example 'admiting', 'sastisfies', 'Moverover', 'Frierdrich', and 'Storminger' in the references). A careful proofreading pass is needed.
  3. [Equation (89)] The case W^⊥ = 0 is included by allowing kappa = 0, but for kappa = 0 the expression with xi is singular and xi itself is not defined. It would be cleaner to state the zero case separately, as is done just before Eq. (81).
  4. [Section 5.1, Eq. (77)] The statement that Eq. (77) follows from Eq. (76) and the tracelessness of the Weyl tensor is used to discard one of the algebraic equations; a short derivation or a reference for that four-dimensional identity would make the reduction easier to verify.

Circularity Check

0 steps flagged · score 2.0 of 10

No substantive circularity: equations (79)-(89) are derived from the paper's own algebraic decomposition and Fefferman-Graham expansion, not fitted to the target conclusion; the final Kerr-de Sitter-like identification is borrowed from the authors' independent prior classification, and the flagged Lemma 6 and sufficiency gaps are correctness concerns rather than circular reductions.

full rationale

The derivation chain is self-contained: Lemma 1 and Proposition 1 provide the algebraic decomposition, Corollary 2 and equations (59)-(65) give the asymptotic Weyl-tensor fall-off, and the type II conditions (72)-(78) are converted by direct substitution into (79)-(80). The functions F, G, f and y are not fitted to the desired form (89); F is an undetermined scalar and is later recast as f^{-3} only after equation (82) forces the conformal Killing equation (85)-(87), so (89) is a consequence, not an input. The final identification with the Kerr-de Sitter-like class does invoke prior work by the same authors ([38], [40]), and this citation is load-bearing for the exact-match claim, but it is an independent published classification (explicit metric construction and the Kerr-Schild type II property [35]) rather than a restatement of the paper's own inputs. Two non-circular correctness caveats are flagged: Lemma 6's lambda>0 extendability proof assumes that every future k-geodesic from D^-(I+) meets I+, a property that fails when horizons are present (e.g. ingoing repeated principal null geodesics in Kerr-de Sitter), so Theorem 2's lambda>0 branch inherits an unproven extendability assumption; and the paper itself states in Section 5.1 that sufficiency of (79)-(80) for type II in a neighborhood is beyond its scope. Score 2 reflects the borrowed self-classification and these proof gaps, not a reduction of the central derivation to its inputs.

Assumptions & free parameters 0 free parameters · 7 assumptions · 0 invented entities

The derivation rests on standard conformal and Fefferman-Graham machinery plus a small number of domain assumptions. There are no fitted constants; the degrees of freedom in the final class are geometric data, namely a locally conformally flat boundary metric and a conformal Killing vector. The only ad hoc assumption is the extendability of the WAND for lambda negative, and arguably for lambda positive given the gap in Lemma 6.

assumptions (7)
  • domain assumption Existence of a smooth conformal compactification (M,g;Omega) with I={Omega=0} and Einstein metric Ric=(n-1)lambda g.
    Used to define conformal infinity and the Fefferman-Graham setup; Section 4, Definition 1.
  • standard math Fefferman-Graham expansion (45) with trace and divergence constraints (47) and explicit forms for g(2) and g(4), equations (56)-(57).
    Quoted from Fefferman-Graham [16,17] and Anderson [1]; Section 4.1.
  • domain assumption Well-posedness of the asymptotic initial value problem with data (gamma0, D) for lambda positive.
    Theorem 1, cited from [2,3,27,29,30]; used to interpret the data (gamma, W perpendicular).
  • standard math Type II Weyl tensors admit a geodesic multiple WAND.
    Durkee-Reall [15]; used in Section 5 to choose geodesic k.
  • ad hoc to paper For lambda negative, k extends transversally to I.
    Explicitly assumed in Section 5 before Lemma 6; not proven.
  • standard math In three dimensions, local conformal flatness is equivalent to vanishing Cotton tensor, and the Bach tensor also vanishes.
    Used in Section 5.1 to simplify equations (79) and (80).
  • domain assumption The classification of Kerr-de Sitter-like metrics with conformally flat I in references [38] and [40] is correct, and their type II property holds.
    Used to identify the data (89) with the KdS-like class; Section 5.1 after Theorem 2.

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Pith. "Pith review of Classification of $\Lambda \neq 0$-vacuum algebraically special spacetimes with conformally flat $\mathscr I$ from Weyl tensor expansion." pith.science (2026). https://pith.science/paper/IQN5MXDR

@misc{pith2026250721292,
  author       = {Pith},
  title        = {Pith review of: Classification of $\Lambda \neq 0$-vacuum algebraically special spacetimes with conformally flat $\mathscr I$ from Weyl tensor expansion},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/IQN5MXDR}},
  note         = {Machine review of arXiv:2507.21292}
}
abstract

We introduce a general algebraic decomposition of Riemann-like and Weyl-like tensors with respect to a non-null vector $u$. We derive Gauss, Codazzi and Ricci-type identities for the Weyl tensor, that allow to relate the components of the spacetime Weyl tensor with intrinsic quantities of the hypersurfaces orthogonal to $u$. Restricting to the case of $\Lambda$-vacuum spacetimes (with $\Lambda \neq 0$ and any dimension) admiting a conformal compactification, we then study the behaviour of the Weyl tensor near $\mathscr I$ by means of an asymptotic expansion {\it \`a la} Fefferman-Graham, where the first terms are explicitly computed. We use these tools to characterize four dimensional algebraically special spacetimes with locally conformally flat $\mathscr{I}$, showing they match exactly the so-called {\it Kerr-de Sitter-like class with conformally flat $\scri$}, thus providing a geometric characterization of this class of spacetimes.

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Works this paper leans on

57 extracted references · 57 canonical work pages

  1. [7]

    Bernardi de Freitas G, Godazgar M, Reall HS. 2015. Uniqueness of the Kerr-de Sitter spacetime as an algebraically special solution in five dimensions. Communications in Mathematical Physics 340, 291-323

  2. [38]

    Mars M, Paetz TT, Senovilla JMM,. 2017. Classification of Kerr-de Sitter-like spacetimes with conformally flat I . Classical and Quantum Gravity 34, 095010

  3. [1]

    Anderson MT. 2005. On the Structure of Asymptotically de Sitter and Anti-de Sitter Spaces. Advances in Theoretical and Mathematical Physics , 8, 861–893

  4. [2]

    Anderson MT. 2005. Existence and stability of even-dimensional asymptotically de Sitter spaces. Annales Henri Poincar´ e6, 801-820

  5. [3]

    Anderson MT, Chru´ sciel PT. 2005. Asymptotically simple solutions of the vacuum Einstein equations in even dimensions. Communications in Mathematical Physics , 260, 557-577

  6. [4]

    Anninos D, Ng DS, Strominger A. 2011. Asymptotic Symmetries and Charges in De Sitter Space. Classical and Quantum Gravity , 28, 175019

  7. [5]

    Ashtekar A, Magnon A. 1984. Asymptotically anti-de Sitter space-times. Classical and Quantum Gravivty , 1, L39. 32

  8. [6]

    Ashtekar A, Das S. 2000. Asymptotically Anti-de Sitter space-times: Conserved quantities. Classical and Quantum Gravity, 17, L17

Show all 57 references
  1. [8]

    Bondi H, van der Burg MGJ, Metzner A WK. 1962. Gravitational waves in general relativity. VII. Waves from axisymmetric isolated systems. Proceedings of the Royal Society A , 269, 21–52

  2. [9]

    Brouwer, L. E. J. 1911. Beweis der Invarianz des n-dimensionalen Gebiets. Mathematische Annalen , 71, 305-313

  3. [10]

    Cao Labora, D. 2020. When Is a Continuous Bijection a Homeomorphism? The American Mathematical Monthly, 126, 547-553

  4. [11]

    Coley A, Milson R, Pravda V, Pravdov´ a A. 2004. Classification of the Weyl tensor in higher dimensions. Classical and Quantum Gravity 21, 033001

  5. [12]

    Comp` ere G, Fiorucci A, Ruzziconi R. 2019. The Λ-BMS 4 group of dS 4 and new boundary conditions for AdS4. Classical and Quantum Gravity , 36, 195017

  6. [13]

    Comp` ere G, Fiorucci A, Ruzziconi R. 2020. The Λ-BMS4 charge algebra. Journal of High Energy Physics , 10, 205

  7. [14]

    Chru´ sciel PT, Cong W, Gray F. 2025. Kerr-AdS type higher dimensional black holes with non-spherical cross-sections of horizons. Classical and Quantum Gravicty 42, 155007

  8. [15]

    Durkee M, Reall H. 2009. A higher dimensional generalization of the geodesic part of the Goldberg–Sachs theorem. Classical and Quantum Gravity 26

  9. [16]

    Fefferman C, Graham CR. 1985. Conformal invariants . Lyon, France: Soci´ et´ e math´ ematique de France

  10. [17]

    Fefferman C, Graham CR. 2012. The Ambient Metric . Princeton, NJ: Princeton University Press

  11. [18]

    Fern´ andez-´Alvarez F, Senovilla JMM. 2020. Gravitational radiation condition at infinity with a positive cosmological constant. Physical Review D , 102, 101502

  12. [19]

    Fern´ andez-´Alvarez F, Senovilla JMM. 2022. Asymptotic Structure with a Positive Cosmological Constant. Classical and Quantum Gravity , 39, 165012

  13. [20]

    Fern´ andez-´Alvarez F, Senovilla JMM. 2022. The peeling theorem with arbitrary cosmological constant. Classical and Quantum Gravity , 39 10LT01

  14. [21]

    Friedrich H. 2002. Conformal Einstein evolution. Lecture Notes in Physics , 604, 1-50. Springer, Berlin- Heidelberg

  15. [22]

    Friedrich H. 1891. The asymptotic characteristic initial value problem for Einstein’s vacuum field equations as an initial value problem for a first-order quasilinear symmetric hyperbolic system. Proceedings of the Royal Society of London A 378, 401-421

  16. [23]

    Friedrich H. 1981. On the regular and asymptotic characteristic initial value problem for Einstein’s vacuum field equations.Proceedings of the Royal Society of London A 375, 169-185. 33

  17. [24]

    Friedrich H. 1986. Existence and structure of past asymptotically simple solutions of Einstein’s field equa- tions with positive cosmological constant. Journal of Geometry and Physics 3, 101-117

  18. [25]

    Graham CR, Lee JM. 1991. Einstein metrics with prescribed conformal infinity on the ball. Advances in Mathematics 87, 186-225

  19. [26]

    Hawking SW, Ellis GFR. 1973. The Large Scale Structure of Space-Time. Cambridge University Press, Cambridge

  20. [27]

    Hintz P. 2023. Asymptotically de Sitter metrics from scattering data in all dimensions. arXiv:2311.02739 [gr-qc]

  21. [28]

    Hoque SK J, Krtouˇ s P, Pe´ on-Nieto C. 2025. Conformal Einstein equation and symplectic flux with a positive cosmological constant. arXiv:2504.20845 [gr-qc]

  22. [29]

    Kami´ nski W. 2023. Well-posedness of the ambient metric equations and stability of even dimensional asymptotically de Sitter spacetimes, Communications in Mathematical Physics 401, 2959-2998

  23. [30]

    Kichenassamy S. 2004. On a conjecture of Fefferman and Graham Advances in Mathematics 184, 268-288

  24. [31]

    On the uniqueness of the Kerr-(A)dS metric as a type II(D) solution in six dimensions

    Kokoˇ ska D, Ortaggio M. On the uniqueness of the Kerr-(A)dS metric as a type II(D) solution in six dimensions. arXiv:2505.10532 [gr-qc]

  25. [32]

    Lee J, Wald RM. 1990. Local symmetries and constraints. Journal of Mathematical Physics , 31, 725

  26. [33]

    LIGO Scientific, Virgo Collaboration. 2016. Observation of Gravitational Waves from a Binary Black Hole Merger. Physical Review Letters 116, 061102

  27. [34]

    Maldacena JM. 1999. The Large-N Limit of Superconformal Field Theories and Supergravity. International Journal of Theoretical Physics , 38, 1113–1133

  28. [35]

    M´ alek T, Pravda V. 2011. Kerr-Schild spacetimes with an (A)dS background. Classical and Quantum Gravity 28, 125011

  29. [36]

    Mars M. 1999. A spacetime characterization of the Kerr metric. Classical and Quantum Gravity 16, 2507- 2523

  30. [37]

    Mars M, Paetz TT, Senovilla JMM, Simon W. 2016. Characterization of (asymptotically) Kerr-de Sitter-like spacetimes at null infinity. Classical and Quantum Gravity 33, 155001

  31. [39]

    Mars M, Pe´ on-Nieto C. 2021. Free data at spacelike I and characterization of Kerr-de Sitter in all dimen- sions. The European Physical Journal C 81, 914

  32. [40]

    Mars M, Pe´ on-Nieto C. 2022. Classification of Kerr-de Sitter-like spacetimes with conformally flat I in all dimensions. Physical Review D 105, 044027

  33. [41]

    Mars M, Pe´ on-Nieto C. 2022. Covariant classification of conformal Killing vectors of locally conformally flat n-manifolds with an application to Kerr-de Sitter. Physical Review D 106, 084045. 34

  34. [42]

    Mars M, Senovilla JMM. 2015. A spacetime characterization of the Kerr-NUT-(A)de Sitter and related metrics. Annales Henri Poincar´ e16, 1509-1550

  35. [43]

    Milson R, Coley A, Pravda V, Pravdov´ a A. 2005. Alignment and algebraically special tensors in Lorentzian geometry. International Journal of Geometric Methods in Modern Physiscs 2, 41

  36. [44]

    Newman E, Penrose R. 1962. An Approach to Gravitational Radiation by a Method of Spin Coefficients. Journal of Mathematical Physics 3, 566–578

  37. [45]

    Ortaggio M. 2009. Bel–Debever criteria for the classification of the Weyl tensor in higher dimensions. Classical and Quantum Gravity 26, 195015

  38. [46]

    Ortaggio M., Pravda V., Pravdov´ a A. 2009. Higher dimensional Kerr-Schild spacetimes. Classical and Quantum Gravity 26, 025008

  39. [47]

    Ortaggio M, Pravdov´ a A. 2014. Asymptotic behaviour of the Weyl tensor in higher dimensions. Physical Review D 90, 104011

  40. [48]

    Penrose R. 1963. Asymptotic Properties of Fields and Space-Times. Physical Review Letters, 10, 66

  41. [49]

    Penrose R. 1965. Zero rest-mass fields including gravitation: asymptotic behaviour. Proceedings of the Royal Society A , 284, 159–203

  42. [50]

    Poole A, Skenderis K, Taylor M. 2022. Charges, conserved quantities, and fluxes in de Sitter spacetime. Physical Review D , 106, L061901

  43. [51]

    Rodnianski I, Shlapentokh-Rothman Y. 2018. The Asymptotically Self-Similar Regime for the Einstein Vacuum Equations. Geometric and Functional Analysis, 28, 755-878

  44. [52]

    Gravitational waves in general relativity

    Sachs R. Gravitational waves in general relativity. VI. The outgoing radiation condition. Proceedings of the Royal Society A , 264, 309–338

  45. [53]

    Sachs R. 1962. Gravitational waves in general relativity. VIII. Waves in asymptotically flat space-times. Proceedings of the Royal Society A , 270, 103–126

  46. [54]

    Skenderis K, Solodukhin SN. 2000. Quantum effective action from the AdS/CFT correspondence. Physics Letters B 472, 316-322

  47. [55]

    Starobinsky AA. 1983. Isotropization of arbitrary cosmological expansion given an effective cosmological constant. Journal of Experimental and Theoretical Physics Letters 37, 55-58

  48. [56]

    Storminger A. 2001. The dS/CFT correspondence. Journal of High Energy Physics , 2001, 034

  49. [57]

    conserved quantities

    Wald RM, Zoupas A. 2000. General definition of “conserved quantities” in general relativity and other theories of gravity. Physical Review D , 61, 084027. 35

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