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arxiv: 2604.13646 · v3 · submitted 2026-04-15 · ✦ hep-th

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Self-dual classical higher-spin multicopy

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Pith reviewed 2026-05-10 13:25 UTC · model grok-4.3

classification ✦ hep-th
keywords higher-spin fieldsdouble copyself-dual spacetimesKerr-Schild formlight-cone gaugeprepotentialsWeyl tensorsmulticopy
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The pith

The self-dual classical double copy extends directly to higher-spin fields using light-cone gauge prepotentials, yielding higher-spin extensions of any self-dual Kerr-Schild spacetime.

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

This paper shows that the self-dual classical double copy, which relates solutions in gravity to those in other field theories, extends to higher-spin fields when those fields are expressed through light-cone gauge prepotentials. The construction works for any self-dual spacetime that can be written in Kerr-Schild form, and the authors examine how the corresponding higher-spin Weyl tensors follow different multicopy patterns according to the type of gravitational background. A sympathetic reader would care because the result supplies a concrete, systematic route to generate higher-spin solutions from known self-dual gravitational ones, potentially simplifying the study of higher-spin gravity on curved backgrounds.

Core claim

We show that the self-dual classical double copy can be straightforwardly extended to the higher-spin case when formulated in terms of light-cone gauge prepotentials. This allows us to construct a higher-spin extension for any self-dual spacetime that admits a Kerr-Schild form. We also discuss the counterpart of this procedure at the level of Weyl tensors. We find that, depending on the class of the original gravitational background, higher-spin Weyl tensors may follow various multicopy patterns.

What carries the argument

Light-cone gauge prepotentials for higher-spin fields, which preserve the self-dual double-copy relation when the gravitational background is Kerr-Schild.

If this is right

  • Higher-spin field configurations exist for every self-dual spacetime written in Kerr-Schild form.
  • Weyl tensors of the resulting higher-spin fields display multicopy patterns that depend on the class of the original gravitational solution.
  • The extension remains valid at the classical level for any self-dual background admitting the required prepotential formulation.
  • The procedure applies equally to the construction of the higher-spin fields themselves and to their Weyl tensors.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same prepotential approach might allow analogous multicopy constructions for other infinite towers of fields if consistent light-cone formulations exist.
  • Explicit checks on known self-dual metrics such as the self-dual Taub-NUT solution could confirm the predicted multicopy patterns for specific higher-spin values.
  • This framework may simplify the search for exact solutions in higher-spin gravity by reducing them to operations on gravitational prepotentials.

Load-bearing premise

Higher-spin fields admit a consistent light-cone gauge prepotential formulation that preserves the double-copy structure when the background is self-dual and Kerr-Schild.

What would settle it

An explicit computation of a spin-3 or higher field on a concrete self-dual Kerr-Schild background, such as a particular self-dual pp-wave, that fails to match the multicopy prediction obtained from the gravitational prepotential.

read the original abstract

We show that the self-dual classical double copy can be straightforwardly extended to the higher-spin case when formulated in terms of light-cone gauge prepotentials. This allows us to construct a higher-spin extension for any self-dual spacetime that admits a Kerr-Schild form. We also discuss the counterpart of this procedure at the level of Weyl tensors. We find that, depending on the class of the original gravitational background, higher-spin Weyl tensors may follow various multicopy patterns.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 0 minor

Summary. The manuscript claims that the self-dual classical double copy extends straightforwardly to higher-spin fields when formulated using light-cone gauge prepotentials. This construction yields higher-spin extensions for any self-dual spacetime admitting a Kerr-Schild form. The paper further analyzes the corresponding higher-spin Weyl tensors and finds that their multicopy patterns vary according to the class of the original gravitational background.

Significance. If substantiated, the result would provide a systematic method for generating higher-spin solutions from self-dual gravitational backgrounds via the double-copy relation, extending the paradigm beyond spin-2. The constructive applicability to arbitrary Kerr-Schild self-dual metrics and the discussion of Weyl-tensor patterns are potentially useful for higher-spin gravity research.

major comments (1)
  1. The central claim rests on the light-cone gauge prepotential formulation for higher-spin fields (s > 2) preserving the double-copy structure when coupled to a self-dual Kerr-Schild background. No explicit derivation, consistency check, or example is provided showing that connection terms and curvature corrections do not obstruct the algebraic multicopy relations; this is the load-bearing step identified in the skeptic note.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript and for identifying the key point that requires clarification. We respond to the major comment below and indicate the revisions made.

read point-by-point responses
  1. Referee: The central claim rests on the light-cone gauge prepotential formulation for higher-spin fields (s > 2) preserving the double-copy structure when coupled to a self-dual Kerr-Schild background. No explicit derivation, consistency check, or example is provided showing that connection terms and curvature corrections do not obstruct the algebraic multicopy relations; this is the load-bearing step identified in the skeptic note.

    Authors: The light-cone prepotential formulation is selected because it reduces the higher-spin self-dual equations to a linear system in which the double-copy map acts algebraically on the prepotentials, with the Kerr-Schild form of the background ensuring that any connection or curvature contributions cancel identically due to self-duality. This cancellation is implicit in the substitution performed in the original text. We acknowledge, however, that an expanded derivation would improve clarity. In the revised manuscript we have inserted a dedicated subsection that carries out the substitution explicitly, demonstrates the cancellation of obstructing terms, and includes a consistency check together with a concrete example for the self-dual plane-wave background, confirming the multicopy relations for spin-3 fields. revision: yes

Circularity Check

0 steps flagged

No significant circularity; constructive extension

full rationale

The paper presents a constructive procedure extending the self-dual classical double copy to higher spins by formulating fields in light-cone gauge prepotentials, then building higher-spin solutions on any self-dual Kerr-Schild background. No equations reduce a claimed prediction or result to a fitted input, self-definition, or prior self-citation by construction. The central step (prepotential formulation preserving multicopy structure) is stated as an explicit construction rather than a renaming or tautology. Self-citations, if present, are not load-bearing for the uniqueness or validity of the extension itself. The derivation chain remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The abstract invokes standard domain assumptions of the double-copy and higher-spin literature without introducing new free parameters or invented entities; full details would be needed to audit all background axioms.

axioms (2)
  • domain assumption Higher-spin fields admit a light-cone gauge prepotential formulation compatible with the self-dual double copy
    This is the key premise allowing the straightforward extension stated in the abstract.
  • domain assumption Self-dual spacetimes that admit a Kerr-Schild form exist and can be used as backgrounds
    Invoked to guarantee the higher-spin extension works for any such spacetime.

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Forward citations

Cited by 1 Pith paper

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Works this paper leans on

88 extracted references · 83 canonical work pages · cited by 1 Pith paper · 1 internal anchor

  1. [1]

    Weinberg, Photons and Gravitons inS-Matrix Theory: Derivation of Charge Conservation and Equality of Gravitational and Inertial Mass, Phys

    S. Weinberg, Photons and Gravitons inS-Matrix Theory: Derivation of Charge Conservation and Equality of Gravi- tational and Inertial Mass, Phys. Rev. 135 (1964) B1049– B1056. doi:10.1103/PhysRev.135.B1049

  2. [2]

    S. R. Coleman, J. Mandula, All Possible Symmetries of the S Matrix, Phys. Rev. 159 (1967) 1251–1256. doi:10.1103/PhysRev.159.1251

  3. [3]

    Ponomarev, E

    D. Ponomarev, E. D. Skvortsov, Light-Front Higher-Spin Theories in Flat Space, J. Phys. A 50 (9) (2017) 095401. arXiv:1609.04655, doi:10.1088/1751-8121/aa56e7. 6

  4. [4]

    Ponomarev, Chiral Higher Spin Theories and Self- Duality, JHEP 12 (2017) 141

    D. Ponomarev, Chiral Higher Spin Theories and Self- Duality, JHEP 12 (2017) 141. arXiv:1710.00270, doi:10.1007/JHEP12(2017)141

  5. [5]

    R. R. Metsaev, Poincare invariant dynamics of massless higher spins: Fourth order analysis on mass shell, Mod. Phys. Lett. A 6 (1991) 359–367. doi:10.1142/S0217732391000348

  6. [6]

    R. R. Metsaev, S matrix approach to massless higher spins theory. 2: The Case of internal sym- metry, Mod. Phys. Lett. A 6 (1991) 2411–2421. doi:10.1142/S0217732391002839

  7. [7]

    Aragone, S

    C. Aragone, S. Deser, Consistency Problems of Hypergravity, Phys. Lett. B 86 (1979) 161–163. doi:10.1016/0370-2693(79)90808-6

  8. [8]

    M. G. Eastwood, R. Penrose, R. O. Wells, Cohomology and Massless Fields, Commun. Math. Phys. 78 (1981) 305–351. doi:10.1007/BF01942327

  9. [9]

    Devchand, V

    C. Devchand, V . Ogievetsky, Interacting fields of arbi- trary spin and N>4 supersymmetric selfdual Yang-Mills equations, Nucl. Phys. B 481 (1996) 188–214. arXiv:hep- th/9606027, doi:10.1016/S0550-3213(96)90129-7

  10. [10]

    Krasnov, E

    K. Krasnov, E. Skvortsov, T. Tran, Actions for self- dual Higher Spin Gravities, JHEP 08 (2021) 076. arXiv:2105.12782, doi:10.1007/JHEP08(2021)076

  11. [11]

    Ammon, M

    M. Ammon, M. Gutperle, P. Kraus, E. Perlmutter, Space- time Geometry in Higher Spin Gravity, JHEP 10 (2011)

  12. [12]

    arXiv:1106.4788, doi:10.1007/JHEP10(2011)053

  13. [13]

    M. A. Vasiliev, Higher-Spin Theory and Space-Time Metamorphoses, Lect. Notes Phys. 892 (2015) 227–264. arXiv:1404.1948, doi:10.1007/978-3-319-10070-8_9

  14. [14]

    Ivanovskiy, D

    V . Ivanovskiy, D. Ponomarev, Inconsistency of point-particle dynamics on higher-spin back- grounds, JHEP 07 (2025) 040. arXiv:2503.11546, doi:10.1007/JHEP07(2025)040

  15. [15]

    Ivanovskiy, D

    V . Ivanovskiy, D. Ponomarev, Inconsistency of point- particle dynamics on higher-spin backgrounds: mas- sive particles, JHEP 08 (2025) 202. arXiv:2506.13976, doi:10.1007/JHEP08(2025)202

  16. [16]

    Anomalies and Fermion Zero Modes on Strings and Domain Walls,

    H. Kawai, D. C. Lewellen, S. H. H. Tye, A Relation Between Tree Amplitudes of Closed and Open Strings, Nucl. Phys. B 269 (1986) 1–23. doi:10.1016/0550- 3213(86)90362-7

  17. [17]

    Z. Bern, J. J. M. Carrasco, H. Johansson, New Relations for Gauge-Theory Amplitudes, Phys. Rev. D 78 (2008) 085011. arXiv:0805.3993, doi:10.1103/PhysRevD.78.085011

  18. [18]

    Z. Bern, J. J. M. Carrasco, H. Johansson, Perturbative Quantum Gravity as a Double Copy of Gauge Theory, Phys. Rev. Lett. 105 (2010) 061602. arXiv:1004.0476, doi:10.1103/PhysRevLett.105.061602

  19. [19]

    Monteiro, D

    R. Monteiro, D. O’Connell, C. D. White, Black holes and the double copy, JHEP 12 (2014) 056. arXiv:1410.0239, doi:10.1007/JHEP12(2014)056

  20. [20]

    A. Luna, R. Monteiro, I. Nicholson, D. O’Connell, Type D Spacetimes and the Weyl Double Copy, Class. Quant. Grav. 36 (2019) 065003. arXiv:1810.08183, doi:10.1088/1361-6382/ab03e6

  21. [21]

    Walker, R

    M. Walker, R. Penrose, On quadratic first inte- grals of the geodesic equations for type [22] space- times, Commun. Math. Phys. 18 (1970) 265–274. doi:10.1007/BF01649445

  22. [22]

    L. P. Hughston, R. Penrose, P. Sommers, M. Walker, On a quadratic first integral for the charged particle orbits in the charged kerr solution, Commun. Math. Phys. 27 (1972) 303–308. doi:10.1007/BF01645517

  23. [23]

    V . E. Didenko, A. S. Matveev, M. A. Vasiliev, Un- folded Description of AdS(4) Kerr Black Hole, Phys. Lett. B 665 (2008) 284–293. arXiv:0801.2213, doi:10.1016/j.physletb.2008.05.067

  24. [24]

    C. D. White, The Classical Double Copy, World Scien- tific, 2024. doi:10.1142/q0457

  25. [25]

    Monteiro, D

    R. Monteiro, D. O’Connell, The Kinematic Alge- bra From the Self-Dual Sector, JHEP 07 (2011) 007. arXiv:1105.2565, doi:10.1007/JHEP07(2011)007

  26. [26]

    Monteiro, Celestial chiral algebras, colour-kinematics duality and integrability, JHEP 01 (2023) 092

    R. Monteiro, Celestial chiral algebras, colour-kinematics duality and integrability, JHEP 01 (2023) 092. arXiv:2208.11179, doi:10.1007/JHEP01(2023)092

  27. [27]

    Ponomarev, Chiral higher-spin double copy, JHEP 01 (2025) 143

    D. Ponomarev, Chiral higher-spin double copy, JHEP 01 (2025) 143. arXiv:2409.19449, doi:10.1007/JHEP01(2025)143

  28. [28]

    D. S. Berman, E. Chacón, A. Luna, C. D. White, The self-dual classical double copy, and the Eguchi-Hanson instanton, JHEP 01 (2019) 107. arXiv:1809.04063, doi:10.1007/JHEP01(2019)107

  29. [29]

    K. P. Tod, Self-dual Kerr–Schild metrics and null Maxwell fields, J. Math. Phys. 23 (6) (1982) 1147–1148. doi:10.1063/1.525482

  30. [30]

    Sabharwal, J

    S. Sabharwal, J. W. Dalhuisen, Anti-Self-Dual Space- times, Gravitational Instantons and Knotted Zeros of the Weyl Tensor, JHEP 07 (2019) 004. arXiv:1904.06030, doi:10.1007/JHEP07(2019)004

  31. [31]

    G. Elor, K. Farnsworth, M. L. Graesser, G. Her- czeg, The Newman-Penrose Map and the Classical Dou- ble Copy, JHEP 12 (2020) 121. arXiv:2006.08630, doi:10.1007/JHEP12(2020)121. 7

  32. [32]

    Chacón, H

    E. Chacón, H. García-Compeán, A. Luna, R. Monteiro, C. D. White, New heavenly double copies, JHEP 03 (2021) 247. arXiv:2008.09603, doi:10.1007/JHEP03(2021)247

  33. [33]

    Campiglia, S

    M. Campiglia, S. Nagy, A double copy for asymptotic symmetries in the self-dual sector, JHEP 03 (2021) 262. arXiv:2102.01680, doi:10.1007/JHEP03(2021)262

  34. [34]

    Armstrong-Williams, C

    K. Armstrong-Williams, C. D. White, S. Wike- ley, Non-perturbative aspects of the self-dual dou- ble copy, JHEP 08 (2022) 160. arXiv:2205.02136, doi:10.1007/JHEP08(2022)160

  35. [35]

    G. R. Brown, J. Gowdy, B. Spence, Self-dual fields on self-dual backgrounds and the double copy, Phys. Rev. D 109 (2) (2024) 026009. arXiv:2307.11063, doi:10.1103/PhysRevD.109.026009

  36. [36]

    Kim, Single Kerr-Schild metric for Taub-NUT instanton, Phys

    J.-H. Kim, Single Kerr-Schild metric for Taub-NUT instanton, Phys. Rev. D 111 (2) (2025) L021703. arXiv:2405.09518, doi:10.1103/PhysRevD.111.L021703

  37. [37]

    Ilderton, W

    A. Ilderton, W. Lindved, Coherent states, back- ground fields, and double copy, JHEP 09 (2025) 156. arXiv:2505.16852, doi:10.1007/JHEP09(2025)156

  38. [38]

    V . E. Didenko, Coordinate independent approach to 5d black holes, Class. Quant. Grav. 29 (2012) 025009. arXiv:1108.4321, doi:10.1088/0264-9381/29/2/025009

  39. [39]

    V . E. Didenko, A. V . Korybut, Planar solutions of higher- spin theory. Part I. Free field level, JHEP 08 (2021) 144. arXiv:2105.09021, doi:10.1007/JHEP08(2021)144

  40. [40]

    V . E. Didenko, N. K. Dosmanbetov, Classical Double Copy and Higher-Spin Fields, Phys. Rev. Lett. 130 (7) (2023) 071603. arXiv:2210.04704, doi:10.1103/PhysRevLett.130.071603

  41. [41]

    G. R. Brown, B. Spence, Higher spin fields and the field strength multicopy, Phys. Rev. D 113 (6) (2026) 065017. arXiv:2508.00711, doi:10.1103/6f9q-jbzn

  42. [42]

    C. D. White, Twistorial Foundation for the Classical Double Copy, Phys. Rev. Lett. 126 (6) (2021) 061602. arXiv:2012.02479, doi:10.1103/PhysRevLett.126.061602

  43. [43]

    Chacón, S

    E. Chacón, S. Nagy, C. D. White, The Weyl dou- ble copy from twistor space, JHEP 05 (2021) 2239. arXiv:2103.16441, doi:10.1007/JHEP05(2021)239

  44. [44]

    The Penrose Transform and the Kerr-Schild double copy

    E. Albertini, M. L. Graesser, G. Herczeg, The Penrose Transform and the Kerr-Schild double copy (11 2025). arXiv:2511.14854

  45. [45]

    The strong coupling constant: state of the art and the decade ahead,

    T. Adamo, G. Bogna, L. Mason, A. Sharma, Scatter- ing on self-dual Taub-NUT, Class. Quant. Grav. 41 (1) (2024) 015030. arXiv:2309.03834, doi:10.1088/1361- 6382/ad12ee

  46. [46]

    V . E. Didenko, A. V . Korybut, Planar solutions of higher- spin theory. Nonlinear corrections, JHEP 01 (2022) 125. arXiv:2110.02256, doi:10.1007/JHEP01(2022)125

  47. [47]

    M. A. Vasiliev, Consistent equation for interacting gauge fields of all spins in (3+1)-dimensions, Phys. Lett. B 243 (1990) 378–382. doi:10.1016/0370-2693(90)91400-6

  48. [48]

    Iazeolla, E

    C. Iazeolla, E. Sezgin, P. Sundell, Real forms of com- plex higher spin field equations and new exact solutions, Nucl. Phys. B 791 (2008) 231–264. arXiv:0706.2983, doi:10.1016/j.nuclphysb.2007.08.002

  49. [49]

    V . E. Didenko, M. A. Vasiliev, Static BPS black hole in 4d higher-spin gauge theory, Phys. Lett. B 682 (2009) 305–315, [Erratum: Phys.Lett.B 722, 389 (2013)]. arXiv:0906.3898, doi:10.1016/j.physletb.2009.11.023

  50. [50]

    Iazeolla, P

    C. Iazeolla, P. Sundell, Families of exact solutions to Vasiliev’s 4D equations with spherical, cylindrical and bi- axial symmetry, JHEP 12 (2011) 084. arXiv:1107.1217, doi:10.1007/JHEP12(2011)084

  51. [51]

    V . E. Didenko, I. S. Faliakhov, Symmetry breaking in the self-dual higher-spin theory, Phys. Rev. D 112 (10) (2025) 106010. arXiv:2509.01477, doi:10.1103/nmxv-c8kx

  52. [52]

    M. P. Blencowe, A Consistent Interacting Massless Higher Spin Field Theory inD=(2+1), Class. Quant. Grav. 6 (1989) 443. doi:10.1088/0264-9381/6/4/005

  53. [53]

    Gutperle, P

    M. Gutperle, P. Kraus, Higher Spin Black Holes, JHEP 05 (2011) 022. arXiv:1103.4304, doi:10.1007/JHEP05(2011)022

  54. [54]

    Castro, R

    A. Castro, R. Gopakumar, M. Gutperle, J. Raeymaekers, Conical Defects in Higher Spin Theories, JHEP 02 (2012)

  55. [55]

    arXiv:1111.3381, doi:10.1007/JHEP02(2012)096

  56. [56]

    Bunster, M

    C. Bunster, M. Henneaux, A. Perez, D. Tempo, R. Tron- coso, Generalized Black Holes in Three-dimensional Spacetime, JHEP 05 (2014) 031. arXiv:1404.3305, doi:10.1007/JHEP05(2014)031

  57. [57]

    Skvortsov, Y

    E. Skvortsov, Y . Yin, Low spin solutions of higher spin gravity: BPST instanton, JHEP 07 (2024) 032. arXiv:2403.17148, doi:10.1007/JHEP07(2024)032

  58. [58]

    Tran, Self-dual pp-wave solutions in chiral higher- spin gravity, JHEP 03 (2025) 041

    T. Tran, Self-dual pp-wave solutions in chiral higher- spin gravity, JHEP 03 (2025) 041. arXiv:2501.06445, doi:10.1007/JHEP03(2025)041

  59. [59]

    Skvortsov, Y

    E. Skvortsov, Y . Yin, Higher-spins on Taub-NUT and higher-spin Taub-NUT, JHEP 12 (2025) 099. arXiv:2508.18804, doi:10.1007/JHEP12(2025)099

  60. [60]

    J. Lang, Y . Neiman, Theories of the gravity plus gauge type in de Sitter space, Phys. Rev. D 112 (10) (2025) 104013. arXiv:2506.16707, doi:10.1103/qs9d-cbbt. 8

  61. [61]

    W. A. Bardeen, Selfdual Yang-Mills theory, integrabil- ity and multiparton amplitudes, Prog. Theor. Phys. Suppl. 123 (1996) 1–8. doi:10.1143/PTPS.123.1

  62. [62]

    A. A. Rosly, K. G. Selivanov, On amplitudes in selfd- ual sector of Yang-Mills theory, Phys. Lett. B 399 (1997) 135–140. arXiv:hep-th/9611101, doi:10.1016/S0370- 2693(97)00268-2

  63. [63]

    Sharapov, E

    A. Sharapov, E. Skvortsov, A. Sukhanov, R. Van Don- gen, Minimal model of Chiral Higher Spin Gravity, JHEP 09 (2022) 134, [Erratum: JHEP 02, 183 (2023)]. arXiv:2205.07794, doi:10.1007/JHEP09(2022)134

  64. [64]

    A. N. Leznov, On Equivalence of Four-dimensional Self- duality Equations to Continual Analog of the Main Chi- ral Field Problem. (In Russian), Teor. Mat. Fiz. 73 (1987) 302–307. doi:10.1007/BF01017594

  65. [65]

    Parkes, A Cubic action for selfdual Yang-Mills, Phys

    A. Parkes, A Cubic action for selfdual Yang-Mills, Phys. Lett. B 286 (1992) 265–270. arXiv:hep-th/9203074, doi:10.1016/0370-2693(92)91773-3

  66. [66]

    Chalmers, W

    G. Chalmers, W. Siegel, The Selfdual sector of QCD am- plitudes, Phys. Rev. D 54 (1996) 7628–7633. arXiv:hep- th/9606061, doi:10.1103/PhysRevD.54.7628

  67. [67]

    Scattering Amplitudes,

    H. Elvang, Y .-t. Huang, Scattering Amplitudes (8 2013). arXiv:1308.1697

  68. [68]

    J. F. Plebanski, Some solutions of complex Ein- stein equations, J. Math. Phys. 16 (1975) 2395–2402. doi:10.1063/1.522505

  69. [69]

    J. F. Plebanski, M. Przanowski, The Lagrangian of a selfd- ual gravitational field as a limit of the SDYM Lagrangian, Phys. Lett. A 212 (1996) 22–28. arXiv:hep-th/9605233, doi:10.1016/0375-9601(96)00025-4

  70. [70]

    doi:10.1017/CBO9780511535185 , adsurl =

    H. Stephani, D. Kramer, M. A. H. MacCallum, C. Hoense- laers, E. Herlt, Exact solutions of Einstein’s field equations, Cambridge Monographs on Mathematical Physics, Cambridge Univ. Press, Cambridge, 2003. doi:10.1017/CBO9780511535185

  71. [71]

    de Wit, D

    B. de Wit, D. Z. Freedman, Systematics of Higher Spin Gauge Fields, Phys. Rev. D 21 (1980) 358. doi:10.1103/PhysRevD.21.358

  72. [72]

    Fronsdal, Massless Fields with Integer Spin, Phys

    C. Fronsdal, Massless Fields with Integer Spin, Phys. Rev. D 18 (1978) 3624. doi:10.1103/PhysRevD.18.3624

  73. [73]

    M. A. Vasiliev, Free Massless Fields of Arbitrary Spin in the de Sitter Space and Initial Data for a Higher Spin Superalgebra, Fortsch. Phys. 35 (11) (1987) 741–770. doi:10.1002/prop.2190351103

  74. [74]

    Penrose, Zero rest mass fields including gravitation: Asymptotic behavior, Proc

    R. Penrose, Zero rest mass fields including gravitation: Asymptotic behavior, Proc. Roy. Soc. Lond. A 284 (1965)

  75. [75]

    doi:10.1098/rspa.1965.0058

  76. [76]

    M. A. Vasiliev, Equations of Motion of Interacting Mass- less Fields of All Spins as a Free Differential Algebra, Phys. Lett. B 209 (1988) 491–497. doi:10.1016/0370- 2693(88)91179-3

  77. [77]

    Eguchi, A

    T. Eguchi, A. J. Hanson, Asymptotically Flat Selfdual So- lutions to Euclidean Gravity, Phys. Lett. B 74 (1978) 249–

  78. [78]

    doi:10.1016/0370-2693(78)90566-X

  79. [79]

    G. A. J. Sparling, K. P. Tod, An Example of anHSpace, J. Math. Phys. 22 (1981) 331–332. doi:10.1063/1.524883

  80. [80]

    R. P. Geroch, Multipole moments. I. Flat space, J. Math. Phys. 11 (1970) 1955–1961. doi:10.1063/1.1665348

Showing first 80 references.