Pith. sign in

REVIEW 2 major objections 5 minor 1 cited by

This paper shows that, given a single power-law fall-off near null infinity, Poincaré symmetry fixes the scalar bulk-to-boundary correlator to one form and the fermionic one to a two-branch form, with direct consequences for how boundary co

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-03 07:57 UTC pith:T7C7KGCA

load-bearing objection A clean Ward-identity derivation of scalar and fermionic bulk-to-boundary correlators at null infinity; the fermionic √ω dictionary is the main new bit, and the paper deserves a serious referee despite a hand-wavy Section 4. the 2 major comments →

arxiv 2601.18461 v2 pith:T7C7KGCA submitted 2026-01-26 hep-th

Constraining bulk-to-boundary correlators under Poincar\'e symmetry

classification hep-th
keywords Poincaré symmetryWard identitiesbulk-to-boundary correlatorsnull infinityfall-off conditionsscattering amplitudesfermionic correlatorsboundary-to-boundary correlators
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

Poincaré symmetry alone does not fix ordinary two-point functions, but the paper shows that bulk-to-boundary correlators—the link between fields in the interior of Minkowski spacetime and operators on null infinity—are almost completely fixed once a power-law fall-off is imposed. For a scalar operator, the Ward identities force the correlator to be a single power law of the translation-invariant variable u + n·x', with only an overall constant free. For a fermionic operator in a parity-invariant theory, the correlator is a sum of two pieces: a scalar-like term and a new fermionic term whose exponent is one larger than the fall-off index and which carries the spin structure /n. This changes the dictionary between boundary correlators and momentum-space scattering amplitudes, inserting an extra √ω factor per fermion, and it makes the reduction to boundary-to-boundary correlators depend sharply on the fall-off index, with Δ=1 as the critical value.

Core claim

The central claim is that asymptotic Poincaré invariance plus a fall-off condition fixes the two-point bulk-to-boundary correlator almost completely. Concretely, for a scalar field that falls off as r^{-Δ} near future null infinity, the correlator is D_s(u,Ω;x') = C_s/(u+n·x'-iε)^Δ. For a fermionic field, the parity-invariant correlator is D_f(u,Ω;x') = C_f /n/(u+n·x'-iε)^{Δ+1}, with the /n factor forced because only the null direction survives in the large-r limit; a scalar-like term with the same Δ is also allowed, and in a parity-violating theory two extra γ5 terms appear. The paper derives these forms by expanding the translational and Lorentz Ward identities in powers of 1/r and checkin

What carries the argument

The machinery is the asymptotic expansion of the Poincaré Ward identities in retarded coordinates. The bulk field is tied to a boundary field Σ(u,Ω) by the fall-off Φ ~ Σ/r^Δ, and the bulk-to-boundary correlator D is extracted as the r→∞, u-fixed limit of the bulk two-point function. The Ward identities at leading order reduce to a differential equation in the single variable bu = u+n·x', which is invariant under translations and transforms simply under Lorentz transformations; solving it gives the power-law forms. For fermions, expanding the spinor in a basis of gamma-matrix structures collapses to the single null vector /n because all other structures vanish or are subleading at large r.

Load-bearing premise

The whole argument rests on the assumption that the bulk two-point function has a clean leading power-law fall-off r^{-Δ} (possibly times a logarithm) and that the r→∞ limit commutes with the Ward operators, so that no subleading term contaminates the leading Ward identity.

What would settle it

Compute the r^{-Δ-1} ln r correction to the translation Ward identity for the exact two-point function of a massless interacting scalar whose spectral density behaves as ρ(s) ~ A s^{Δ-2} ln^α s near s=0, the case the paper itself allows; if this logarithmic term fails to cancel in the leading Ward identity, the unique forms (5.1)–(5.2) do not hold for such theories.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Any massless Poincaré-invariant theory with the assumed fall-off has scalar bulk-to-boundary correlators of the unique form C/(u+n·x')^Δ and fermionic ones of the two-term form, so the shape carries no dynamical information beyond the constant and the fall-off index.
  • The relation between boundary correlators and momentum-space scattering amplitudes changes for fermions: each fermionic external line contributes an extra √ω integral factor, which makes the four-point Carrollian integrals finite where the bosonic ones would diverge.
  • Reducing the remaining bulk point to the boundary yields a critical fall-off index Δ=1: for 0≤Δ<1 only a magnetic scalar branch survives, for Δ=1 electric and magnetic branches coexist for scalars and an electric branch appears for fermions, and for Δ>1 the electric branch diverges and needs regularization.
  • A spectral representation of the bulk two-point function forces the zero-mass spectral density to behave as ρ(s) ~ s^{Δ-2}, linking the fall-off index to the infrared behavior; unitary theories with a unique vacuum are argued to satisfy Δ≥1.
  • The constraints survive natural extensions of the fall-off condition, including logarithmic factors and principal-series exponents, and apply to composite operators as well as elementary ones.

Where Pith is reading between the lines

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

  • The strongest consequences are not the two-point forms themselves but the sharp phase structure at Δ=1; if the classification holds, it gives observers a clean way to infer the fall-off index of a bulk theory from the electric/magnetic content of boundary-to-boundary correlators.
  • The √ω factor suggests that fermionic Carrollian amplitudes are systematically better behaved in the infrared than their bosonic counterparts; one could test this in higher-point or loop amplitudes, where the paper's derivation predicts the same factor per external fermion.
  • The decoupling of leading from subleading terms is assumed rather than proved for interacting theories with logarithmic corrections; an explicit counterexample would confine the validity of the unique forms to theories with strictly clean power-law behavior.
  • If the spectral-representation argument for Δ≥1 is correct, the entire 0≤Δ<1 regime of the classification would be unphysical for unitary theories, leaving Δ=1 as the only case where both electric and magnetic branches coexist.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 5 minor

Summary. The paper derives the consequences of Poincaré Ward identities for two-point bulk-to-boundary correlators at null infinity, assuming a power-law fall-off r^{-Δ} for the bulk field. For scalar operators the correlator is claimed to be fixed to D_s = C_s/(u+n·x'-iϵ)^Δ, and for fermions, in parity-invariant theories, to a superposition D = C_s/(u+n·x'-iϵ)^Δ + C_f /n/(u+n·x'-iϵ)^{Δ+1}. The derivation proceeds by expanding the bulk Ward identities asymptotically and showing that the leading terms decouple. The paper then connects the resulting correlators to Carrollian amplitudes, deriving an extra √ω factor in the Fourier transform for fermionic operators, and reduces the bulk-to-boundary correlators to boundary-to-boundary correlators, yielding a classification in terms of electric and magnetic branches for different values of Δ.

Significance. If correct, the central result is a strong and useful constraint: in any Poincaré-invariant theory with the assumed fall-off, the two-point bulk-to-boundary correlator is essentially fixed by symmetry even though the bulk-to-bulk correlator is not. This is a genuine step beyond the usual statement that Poincaré symmetry alone is too weak. The paper also gives an explicit free-Dirac check of the fermionic branch (Sec. 2.2.3), derives a concrete √ω correction to Carrollian amplitude formulae (Sec. 3), and presents explicit four-point examples in Yukawa theory and massless QED (Sec. 3.3). The electric/magnetic classification in Table 3 is potentially useful, but as discussed below it is currently supported by asserted rather than shown integrations.

major comments (2)
  1. [Abstract and Sec. 2.2.2, Eqs. (2.88)-(2.90)] The abstract's central claim — 'fermionic bulk-to-boundary correlators are fixed to a linear superposition of scalar and fermionic branches' — is not true as stated for a general Poincaré-invariant theory. Eq. (2.88) gives four independent branches: the scalar branch, the fermionic branch, and two γ5-containing branches (pseudo-scalar and pseudo-fermionic). Only after imposing parity invariance do the γ5 branches drop, yielding Eq. (2.90) or Eq. (5.2). The abstract and introduction should either explicitly restrict to parity-invariant theories or advertise the four-branch result. This is a load-bearing mismatch between the headline claim and the body's actual result.
  2. [Sec. 4, Eqs. (4.4) and (4.16)] The electric-branch coefficients α(u-v') are stated without derivation. Eq. (4.4) is introduced with 'Interestingly, we find', and Eq. (4.16) with 'It is straightforward to obtain', but the sphere integrals, the regularization (η=ϵ/r'), and the limiting procedures are not shown. These coefficients determine the existence or divergence of the electric branch, which is the basis of Table 3 — one of the paper's advertised outcomes. The authors should display the integrals and their evaluation at least for the cases Δ<1, Δ=1, and Δ>1, so that the table is independently checkable.
minor comments (5)
  1. [Sec. 2.1, after Eq. (2.21)] The statement that 'the leading terms decouple from the subleading ones' is correct, but the reason is not spelled out. In the Lorentz Ward identity, the potentially dangerous r^{-Δ} contribution coming from r n_ν (-n_μ) ∂_u acting on a subleading term r^{-Δ-1}D_1 is proportional to n_[ν n_μ] and therefore vanishes by antisymmetry. Adding one sentence making this explicit would strengthen the presentation.
  2. [Sec. 2.2.2, around Eq. (2.83)] The argument that f^{μν}_3 S_{μν} disappears because S_{μν} n^μ n^ν = 0 is too terse. A term of the form S_{μν} n^μ \bar n^ν does not vanish; it can be rewritten as a combination of 1 and γ5 (e.g. /n/bar n = 2(1+γ5) for a null pair). The authors should state this decomposition explicitly to justify the basis (2.83).
  3. [Sec. 4, Eq. (4.5)] The text uses '0<Δ<1' in Eq. (4.5) while the abstract and Table 3 use '0≤Δ<1'. Please make the range consistent. For Δ=0 the magnetic-branch formula appears well-defined, so the inclusive range is probably intended.
  4. [Sec. 3 and Sec. 2.2.2] Several typos should be fixed: 'explicity' near the start of Sec. 3, 'canoincal' in Sec. 3.1, 'four-dimensinoal' in Sec. 2, 'peudo-scalar' in Sec. 2.2.2, and 'analytical continuity' should be 'analytic continuation' in the iϵ remark of Sec. 2.1.
  5. [Sec. 5, Källén-Lehmann discussion] The claim that unitarity and a unique vacuum imply Δ≥1 is introduced with 'we argue' and is not proven. Since this is a side remark rather than a main result, it would be appropriate to label it as a conjecture or to provide a derivation, especially because the paper later notes possible violations for non-gauge-invariant operators.

Circularity Check

0 steps flagged

No significant circularity: Ward-identity derivation is self-contained.

full rationale

The claimed uniqueness result (5.1)-(5.2) is derived, not assumed. The scalar case starts from the translation and Lorentz Ward identities (2.13), the asymptotic expansion (2.17)/(2.21), and the dictionary (2.19); the leading-order equations (2.22) are obtained by multiplying by r^Delta and taking r to infinity. Equation (2.22a) gives D=F(u+n.x'), and (2.22b) forces delta_A F=0 and (u+n.x')F'+Delta F=0, whose solution is exactly (2.29). The input fall-off exponent Delta enters as the rate r^{-Delta}; the bu^{-Delta} power is a consequence of the Lorentz generator, so the output is not contained in the input by construction. The fermionic case is analogous: (2.78b) with the Clifford basis (2.80)-(2.83) yields differential equations whose solutions are (2.87); the Delta+1 power for the /n branch comes from [S,/n], not from a fitted parameter. The sqrt(omega) factor in the Carrollian dictionary is derived in Section 3.1 from the canonical mode expansion of the free Dirac field (3.8), (3.18), (3.28) and is checked against the integral representation (3.1); it is a normalization convention consistent with the bulk-to-boundary propagator, not an input to the uniqueness derivation. Subleading terms in (2.21) are suppressed by positive powers of 1/r after multiplying the Ward identities by r^Delta and taking the limit, so the leading identities (2.22)/(2.78) are not contaminated. The self-citations ([36], [38], [40], [41], [55], [58]) supply conventions, formulas, and comparisons; none is invoked as a uniqueness theorem or as the source of the central result, so they are not load-bearing. The paper itself flags scope limitations (no global Poincare symmetry in generic asymptotically flat spacetimes; unitarity bound Delta>=1) and a convention-dependent transformation footnote; these are caveats, not circular reductions. The abstract's unqualified statement about the fermionic four-branch result omits the parity-invariance qualifier introduced at (2.88)-(2.90), which is a presentation imprecision rather than a circularity. No equation is set equal to its own input, and no fitted value is relabeled as a prediction.

Axiom & Free-Parameter Ledger

2 free parameters · 6 axioms · 0 invented entities

The central derivation rests on the assumed power-law fall-off and its decoupling from subleading terms, plus Poincaré invariance and parity. The fall-off index Δ and the normalization constants are undetermined inputs. No new particles, fields, or dynamical entities are introduced; the scalar/fermionic/pseudo branches are decompositions of known operator content.

free parameters (2)
  • Fall-off index Δ
    Input parameter characterizing the leading 1/r^Δ fall-off in (2.17)/(2.75); every derived correlator depends on it and Poincaré symmetry alone does not fix it.
  • Normalization constants C_s, C_f, C_pf, C_ps
    Integration constants from solving the first-order ODEs; the paper claims uniqueness only 'up to a normalization constant'.
axioms (6)
  • domain assumption The theory is Poincaré invariant and the boundary Carrollian field theory at I± exists, with Ward identities (2.13)/(2.74).
    Used throughout Section 2; excludes massive theories and generic asymptotically flat spacetimes without global Poincaré symmetry, as the authors note in Section 5.
  • domain assumption Bulk fields admit a power-law asymptotic expansion Φ(x)=Σ(u,Ω)/r^Δ+... near I± with Δ≥0.
    Equation (2.17)/(2.75). This is the central structural input; without a well-defined leading power the Ward identity expansion has nothing to constrain.
  • ad hoc to paper The r→∞ limit commutes with the Ward identity derivatives so that subleading terms in G=D/r^Δ+... decouple.
    Invoked around (2.21)-(2.22); asserted as 'the leading terms decouple from the subleading ones' without a proof for general interacting fields.
  • domain assumption The theory is parity invariant, so γ5 and γ5/n branches are discarded.
    Stated after eq. (2.90): 'pseudo-scalar and pseudo-fermionic branches can not appear in a parity invariant theory.'
  • domain assumption At I+, the leading spinor components are proportional to λ_a and λ†_a, respectively.
    Equations (3.20)-(3.21); this fixes the mode expansions (3.28) and is needed for the √ω factor in (3.37).
  • domain assumption For the unitarity discussion, the Källen-Lehmann spectral representation applies and unitary Poincaré-invariant theories with unique vacuum satisfy Δ≥1.
    Section 5 uses this to argue the Δ<1 regime is excluded; presented as an argument, not a theorem.

pith-pipeline@v1.3.0-alltime-deepseek · 31250 in / 17007 out tokens · 188502 ms · 2026-08-03T07:57:35.480360+00:00 · methodology

0 comments
read the original abstract

It is well known that a general two-point function cannot be uniquely determined by Poincar\'e symmetry. In this paper, we show that bulk-to-boundary correlators are highly constrained after imposing suitable fall-off conditions near future/past null infinity. More precisely, scalar bulk-to-boundary correlators are fixed to a unique form up to a normalization constant, whereas fermionic bulk-to-boundary correlators are fixed to a linear superposition of scalar and fermionic branches. This is established by asymptotically expanding the Ward identities, where upon the leading terms decouple from the subleading ones. In the fermionic branch, the power-law exponent of the bulk-to-boundary correlator is greater by one than the fall-off index. Consequently, we revisit the relation between Carrollian correlators and momentum space scattering amplitudes for fermionic operators. In this context, we find that the Fourier transform bridging the two acquires an extra factor of $\sqrt{\omega}$ for each fermionic operator. Furthermore, we reduce the bulk-to-boundary correlator to the boundary-to-boundary correlator and identify a critical fall-off index $\Delta=1$. For $0 < \Delta < 1$, only a magnetic branch exists for scalars. For $\Delta > 1$, the electric branch is always divergent for both scalar and fermionic branches and thus requires regularization.

Figures

Figures reproduced from arXiv: 2601.18461 by Jiang Long, Jing-Long Yang.

Figure 1
Figure 1. Figure 1: The bulk-to-boundary correlator D. The pole of the bulk-to-boundary correlator should be located on the light ray that connects a bulk field located at x and a boundary operator located at (u, Ω) ∈ I+. In general, this is a function of the translation invariant variable ub = u + n · x. The fact that two-point bulk correlators are largely unconstrained by Poincar´e symmetry, while their boundary counterpart… view at source ↗
Figure 2
Figure 2. Figure 2: The classical value of the boundary field is corrected by the source in the bulk. We use the retarded bulk-to-boundary correlator since we are working in classical physics here. The leading order correction is universal. The subscript j is to distinguish operators inserted at different positions. This can be shown as follows [36] ⟨ Ym j=1 Σj (uj , Ωj , σj )⟩ = Ym j=1 Z d 4 yjD(uj , Ωj ; yj ) ! G(y1, y2, · … view at source ↗
Figure 3
Figure 3. Figure 3: The leading the subleading contributions to the two-point correlation function of the composite operator Σ2 . Now we turn to the fermionic branch and define the boundary-to-boundary correlator Bf (u, Ω; v ′ , Ω ′ ) = lim −r ′∆Df (u, Ω; x ′ ) = Cf lim − r ′∆ (u + n · x ′ − iϵ)∆+1 . (4.14) When Ω ̸= Ω′P , the limit is always 0. Therefore, we conclude that there is no magnetic branch from the fermionic branch… view at source ↗

discussion (0)

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

Forward citations

Cited by 1 Pith paper

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

  1. Spinning bulk-to-boundary correlators in the massless theories with Poincar\'e symmetry

    hep-th 2026-06 unverdicted novelty 6.0

    Bulk-to-boundary correlators for spin-s operators in Poincaré-invariant massless theories are linear superpositions of ISO(2)-fixed tensor structures mapped to non-crossing double-line diagrams that are tensor product...

Reference graph

Works this paper leans on

81 extracted references · 54 linked inside Pith · cited by 1 Pith paper

  1. [1]

    Weinberg,The Quantum Theory of Fields

    S. Weinberg,The Quantum Theory of Fields. Cambridge University Press, 1995

  2. [2]

    Conformal symmetry of critical fluctuations,

    A. M. Polyakov, “Conformal symmetry of critical fluctuations,”JETP Lett.12(1970) 381–383. 42

  3. [3]

    Non-hamiltonian approach to conformal quantum field theory,

    A. M. Polyakov, “Non-hamiltonian approach to conformal quantum field theory,”Soviet Journal of Experimental & Theoretical Physics39(1974), no. 1, 23–42

  4. [4]

    Conformal algebra in space-time and operator product expansion,

    S. Ferrara, P. Gatto, and A. F. Grilla, “Conformal algebra in space-time and operator product expansion,”Springer Tracts Mod. Phys.67(1973) 1–64

  5. [5]

    S matrices from AdS space-time,

    J. Polchinski, “S matrices from AdS space-time,”hep-th/9901076

  6. [6]

    Holography in the flat space limit,

    L. Susskind, “Holography in the flat space limit,”AIP Conf. Proc.493(1999), no. 1, 98–112,hep-th/9901079

  7. [7]

    The Boundary S matrix and the AdS to CFT dictionary,

    S. B. Giddings, “The Boundary S matrix and the AdS to CFT dictionary,”Phys. Rev. Lett.83(1999) 2707–2710,hep-th/9903048

  8. [8]

    What do CFTs tell us about Anti-de Sitter space-times?,

    V. Balasubramanian, S. B. Giddings, and A. E. Lawrence, “What do CFTs tell us about Anti-de Sitter space-times?,”JHEP03(1999) 001,hep-th/9902052

  9. [9]

    A Holographic reduction of Minkowski space-time,

    J. de Boer and S. N. Solodukhin, “A Holographic reduction of Minkowski space-time,” Nucl. Phys. B665(2003) 545–593,hep-th/0303006

  10. [10]

    Local bulk S-matrix elements and CFT singularities,

    M. Gary, S. B. Giddings, and J. Penedones, “Local bulk S-matrix elements and CFT singularities,”Phys. Rev. D80(2009) 085005,0903.4437

  11. [11]

    Gravitational waves in general relativity. 7. Waves from axisymmetric isolated systems,

    H. Bondi, M. G. J. van der Burg, and A. W. K. Metzner, “Gravitational waves in general relativity. 7. Waves from axisymmetric isolated systems,”Proc. Roy. Soc. Lond. A269 (1962) 21–52

  12. [12]

    Gravitational waves in general relativity. 8. Waves in asymptotically flat space-times,

    R. K. Sachs, “Gravitational waves in general relativity. 8. Waves in asymptotically flat space-times,”Proc. Roy. Soc. Lond. A270(1962) 103–126

  13. [13]

    Asymptotic symmetries in gravitational theory,

    R. Sachs, “Asymptotic symmetries in gravitational theory,”Phys. Rev.128(Dec, 1962) 2851–2864

  14. [14]

    Aspects of the BMS/CFT correspondence,

    G. Barnich and C. Troessaert, “Aspects of the BMS/CFT correspondence,”JHEP05 (2010) 062,1001.1541

  15. [15]

    Conformal Carroll groups and BMS symmetry,

    C. Duval, G. W. Gibbons, and P. A. Horvathy, “Conformal Carroll groups and BMS symmetry,”Class. Quant. Grav.31(2014) 092001,1402.5894

  16. [16]

    Conformal Carroll groups,

    C. Duval, G. W. Gibbons, and P. A. Horvathy, “Conformal Carroll groups,”J. Phys. A 47(2014), no. 33, 335204,1403.4213

  17. [17]

    Carroll versus Newton and Galilei: two dual non-Einsteinian concepts of time,

    C. Duval, G. W. Gibbons, P. A. Horvathy, and P. M. Zhang, “Carroll versus Newton and Galilei: two dual non-Einsteinian concepts of time,”Class. Quant. Grav.31(2014) 085016,1402.0657. 43

  18. [18]

    Carroll versus Galilei Gravity,

    E. Bergshoeff, J. Gomis, B. Rollier, J. Rosseel, and T. ter Veldhuis, “Carroll versus Galilei Gravity,”JHEP03(2017) 165,1701.06156

  19. [19]

    Gauging the Carroll Algebra and Ultra-Relativistic Gravity,

    J. Hartong, “Gauging the Carroll Algebra and Ultra-Relativistic Gravity,”JHEP08 (2015) 069,1505.05011

  20. [20]

    Une nouvelle limite non-relativiste du groupe de poincar´ e,

    J.-M. L´ evy-Leblond, “Une nouvelle limite non-relativiste du groupe de poincar´ e,” Annales de l’I.H.P. Physique th´ eorique3(1965), no. 1, 1–12

  21. [21]

    The Carrollian Kaleidoscope,

    A. Bagchi, A. Banerjee, P. Dhivakar, S. Mondal, and A. Shukla, “The Carrollian Kaleidoscope,”2506.16164

  22. [22]

    Celestial Holography,

    S. Pasterski, M. Pate, and A.-M. Raclariu, “Celestial Holography,” inSnowmass 2021. 11, 2021.2111.11392

  23. [23]

    Flat Holography: Aspects of the dual field theory,

    A. Bagchi, R. Basu, A. Kakkar, and A. Mehra, “Flat Holography: Aspects of the dual field theory,”JHEP12(2016) 147,1609.06203

  24. [24]

    On higher-dimensional Carrollian and Galilean conformal field theories,

    B. Chen, R. Liu, and Y.-f. Zheng, “On higher-dimensional Carrollian and Galilean conformal field theories,”SciPost Phys.14(2023), no. 5, 088,2112.10514

  25. [25]

    Carrollian conformal correlators and massless scattering amplitudes,

    K. Nguyen, “Carrollian conformal correlators and massless scattering amplitudes,”JHEP 01(2024) 076,2311.09869

  26. [26]

    An embedding space approach to Carrollian CFT correlators for flat space holography,

    J. Salzer, “An embedding space approach to Carrollian CFT correlators for flat space holography,”JHEP10(2023) 084,2304.08292

  27. [27]

    Poincar´ e constraints on celestial amplitudes,

    Y. T. A. Law and M. Zlotnikov, “Poincar´ e constraints on celestial amplitudes,”JHEP03 (2020) 085,1910.04356. [Erratum: JHEP 04, 202 (2020)]

  28. [28]

    The LargeNlimit of superconformal field theories and supergravity,

    J. M. Maldacena, “The LargeNlimit of superconformal field theories and supergravity,” Adv. Theor. Math. Phys.2(1998) 231–252,hep-th/9711200

  29. [29]

    Gauge theory correlators from noncritical string theory,

    S. S. Gubser, I. R. Klebanov, and A. M. Polyakov, “Gauge theory correlators from noncritical string theory,”Phys. Lett. B428(1998) 105–114,hep-th/9802109

  30. [30]

    Anti-de Sitter space and holography,

    E. Witten, “Anti-de Sitter space and holography,”Advances in Theoretical and Mathematical Physics2(Jan., 1998) 253–291,hep-th/9802150

  31. [31]

    AdS dynamics from conformal field theory,

    T. Banks, M. R. Douglas, G. T. Horowitz, and E. J. Martinec, “AdS dynamics from conformal field theory,”hep-th/9808016

  32. [32]

    Carrollian Perspective on Celestial Holography,

    L. Donnay, A. Fiorucci, Y. Herfray, and R. Ruzziconi, “Carrollian Perspective on Celestial Holography,”Phys. Rev. Lett.129(2022), no. 7, 071602,2202.04702. 44

  33. [33]

    Bridging Carrollian and celestial holography,

    L. Donnay, A. Fiorucci, Y. Herfray, and R. Ruzziconi, “Bridging Carrollian and celestial holography,”Phys. Rev. D107(2023), no. 12, 126027,2212.12553

  34. [34]

    Scattering Amplitudes: Celestial and Carrollian,

    A. Bagchi, S. Banerjee, R. Basu, and S. Dutta, “Scattering Amplitudes: Celestial and Carrollian,”Phys. Rev. Lett.128(2022), no. 24, 241601,2202.08438

  35. [35]

    Carrollian Amplitudes and Celestial Symmetries,

    L. Mason, R. Ruzziconi, and A. Yelleshpur Srikant, “Carrollian Amplitudes and Celestial Symmetries,”2312.10138

  36. [36]

    Feynman rules and loop structure of Carrollian amplitudes,

    W.-B. Liu, J. Long, and X.-Q. Ye, “Feynman rules and loop structure of Carrollian amplitudes,”JHEP05(2024) 213,2402.04120

  37. [37]

    Carrollian Amplitudes from Holographic Correlators,

    L. F. Alday, M. Nocchi, R. Ruzziconi, and A. Yelleshpur Srikant, “Carrollian Amplitudes from Holographic Correlators,”2406.19343

  38. [38]

    On the definition of Carrollian amplitudes in general dimensions,

    W.-B. Liu, J. Long, H.-Y. Xiao, and J.-L. Yang, “On the definition of Carrollian amplitudes in general dimensions,”2407.20816

  39. [39]

    On Carrollian and celestial correlators in general dimensions,

    H. Kulkarni, R. Ruzziconi, and A. Yelleshpur Srikant, “On Carrollian and celestial correlators in general dimensions,”JHEP10(2025) 187,2508.06602

  40. [40]

    Carrollian propagator and amplitude in Rindler spacetime,

    A. Li, J. Long, and J.-L. Yang, “Carrollian propagator and amplitude in Rindler spacetime,”JHEP03(2025) 186,2410.20372

  41. [41]

    Thermal correlator at null infinity,

    J. Long and H.-Y. Xiao, “Thermal correlator at null infinity,”JHEP10(2025) 127, 2501.15714

  42. [42]

    Differential representation for Carrollian correlators,

    S. Chakrabortty, S. Hegde, and A. Maurya, “Differential representation for Carrollian correlators,”JHEP08(2025) 126,2411.09641

  43. [43]

    From AdS correlators to Carrollian amplitudes with the scattering equation,

    T. Adamo, I. Surubaru, and B. Zhu, “From AdS correlators to Carrollian amplitudes with the scattering equation,”2512.03677

  44. [44]

    Towards a flat space Carrollian hologram from AdS 4/CFT3,

    A. Lipstein, R. Ruzziconi, and A. Yelleshpur Srikant, “Towards a flat space Carrollian hologram from AdS 4/CFT3,”JHEP06(2025) 073,2504.10291

  45. [45]

    Operator product expansion in Carrollian CFT,

    K. Nguyen and J. Salzer, “Operator product expansion in Carrollian CFT,”JHEP07 (2025) 193,2503.15607

  46. [46]

    Bulk reconstruction in flat holography,

    B. Chen and Z. Hu, “Bulk reconstruction in flat holography,”JHEP03(2024) 064, 2312.13574

  47. [47]

    Zero Rest-Mass Fields Including Gravitation: Asymptotic Behaviour,

    R. Penrose, “Zero Rest-Mass Fields Including Gravitation: Asymptotic Behaviour,” Proceedings of the Royal Society of London Series A284(Feb., 1965) 159–203. 45

  48. [48]

    Logarithmic asymptotic flatness,

    J. Winicour, “Logarithmic asymptotic flatness,”Foundations of Physics15(1985) 605–616

  49. [49]

    Gravitational waves in general relativity: 14. Bondi expansions and the polyhomogeneity of Scri,

    P. T. Chrusciel, M. A. H. MacCallum, and D. B. Singleton, “Gravitational waves in general relativity: 14. Bondi expansions and the polyhomogeneity of Scri,” gr-qc/9305021

  50. [50]

    Conformal basis for flat space amplitudes,

    S. Pasterski and S.-H. Shao, “Conformal basis for flat space amplitudes,”Phys. Rev. D 96(2017), no. 6, 065022,1705.01027

  51. [51]

    On the formulation of quantized field theories,

    H. Lehmann, K. Symanzik, and W. Zimmermann, “On the formulation of quantized field theories,”Nuovo Cim.1(1955) 205–225

  52. [52]

    M. E. Peskin and D. V. Schroeder,An Introduction to Quantum Field Theory. Addison-Wesley Pub, 1995

  53. [53]

    Theory and applications of fractional differential equations,

    A. A. A. Kilbas, H. M. Srivastava, and J. J. Trujillo, “Theory and applications of fractional differential equations,”North-Holland Mathematics Studies204(2006)

  54. [54]

    Srednicki,Quantum Field Theory

    M. Srednicki,Quantum Field Theory. Cambridge University Press, 2007

  55. [55]

    Symmetry group at future null infinity: Scalar theory,

    W.-B. Liu and J. Long, “Symmetry group at future null infinity: Scalar theory,”Phys. Rev. D107(2023), no. 12, 126002,2210.00516

  56. [56]

    Spinning AdS Propagators,

    M. S. Costa, V. Goncalves, and J. Penedones, “Spinning AdS Propagators,”JHEP09 (2014) 064,1404.5625

  57. [57]

    Penrose and W

    R. Penrose and W. Rindler,Spinors and Space-Time. Cambridge Monographs on Mathematical Physics. Cambridge Univ. Press, Cambridge, UK, 4, 2011

  58. [58]

    Quantum flux operators in the fermionic theory and their supersymmetric extension,

    S.-M. Guo, W.-B. Liu, and J. Long, “Quantum flux operators in the fermionic theory and their supersymmetric extension,”JHEP03(2025) 205,2412.20829

  59. [59]

    Symmetry group at future null infinity II: Vector theory,

    W.-B. Liu and J. Long, “Symmetry group at future null infinity II: Vector theory,” JHEP07(2023) 152,2304.08347

  60. [60]

    Symmetry group at future null infinity III: Gravitational theory,

    W.-B. Liu and J. Long, “Symmetry group at future null infinity III: Gravitational theory,”JHEP10(2023) 117,2307.01068

  61. [61]

    Electromagnetic helicity flux operators in higher dimensions,

    W.-B. Liu, J. Long, and X.-H. Zhou, “Electromagnetic helicity flux operators in higher dimensions,”2407.20077

  62. [62]

    Reduction of topological invariants on null hypersurfaces,

    J. Long and X.-H. Zhou, “Reduction of topological invariants on null hypersurfaces,” 2509.06073. 46

  63. [63]

    Gravitational helicity flux density from two-body systems,

    J. Long and R.-Z. Yu, “Gravitational helicity flux density from two-body systems,” Class. Quant. Grav.42(2025), no. 4, 045005,2403.18627

  64. [64]

    Electromagnetic helicity flux density for radiative systems,

    Z.-Y. Heng, J. Long, R.-Z. Yu, and X.-H. Zhou, “Electromagnetic helicity flux density for radiative systems,”Class. Quant. Grav.43(2026), no. 1, 015016,2507.14966

  65. [65]

    Null Infinity and Unitary Representation of The Poincare Group,

    S. Banerjee, “Null Infinity and Unitary Representation of The Poincare Group,”JHEP 01(2019) 205,1801.10171

  66. [66]

    Elvang and Y.-t

    H. Elvang and Y.-t. Huang,Scattering Amplitudes in Gauge Theory and Gravity. Cambridge University Press, 2015

  67. [67]

    On the definition of the Renormalization Constants in Quantum Electrodynamics,

    G. Kallen, “On the definition of the Renormalization Constants in Quantum Electrodynamics,”Helv. Phys. Acta25(1952), no. 4, 417

  68. [68]

    On the Properties of propagation functions and renormalization contants of quantized fields,

    H. Lehmann, “On the Properties of propagation functions and renormalization contants of quantized fields,”Nuovo Cim.11(1954) 342–357

  69. [69]

    Feynman Propagator for a Free Scalar Field on a Causal Set,

    S. Johnston, “Feynman Propagator for a Free Scalar Field on a Causal Set,”Phys. Rev. Lett.103(2009) 180401,0909.0944

  70. [70]

    I. S. Gradshteyn, I. M. Ryzhik, A. Jeffrey, and D. Zwillinger,Table of Integrals, Series, and Products. 2007

  71. [71]

    Itzykson and Zuber,Quantum Field Theory

    C. Itzykson and Zuber,Quantum Field Theory. Dover Publications, 2006

  72. [72]

    The Infrared behavior of gluon and ghost propagators in Landau gauge QCD,

    L. von Smekal, R. Alkofer, and A. Hauck, “The Infrared behavior of gluon and ghost propagators in Landau gauge QCD,”Phys. Rev. Lett.79(1997) 3591–3594, hep-ph/9705242

  73. [73]

    Nonperturbative Landau gauge and infrared critical exponents in QCD,

    D. Zwanziger, “Nonperturbative Landau gauge and infrared critical exponents in QCD,” Phys. Rev. D65(2002) 094039,hep-th/0109224

  74. [74]

    On the infrared exponent for gluon and ghost propagation in Landau gauge QCD,

    C. Lerche and L. von Smekal, “On the infrared exponent for gluon and ghost propagation in Landau gauge QCD,”Phys. Rev. D65(2002) 125006,hep-ph/0202194

  75. [75]

    The Gluon Is Massive: A Lattice Calculation of the Gluon Propagator in the Landau Gauge,

    J. E. Mandula and M. Ogilvie, “The Gluon Is Massive: A Lattice Calculation of the Gluon Propagator in the Landau Gauge,”Phys. Lett. B185(1987) 127–132

  76. [76]

    Positivity violation for the lattice Landau gluon propagator,

    A. Cucchieri, T. Mendes, and A. R. Taurines, “Positivity violation for the lattice Landau gluon propagator,”Phys. Rev. D71(2005) 051902,hep-lat/0406020

  77. [77]

    Scaling behavior and positivity violation of the gluon propagator in full QCD,

    P. O. Bowman, U. M. Heller, D. B. Leinweber, M. B. Parappilly, A. Sternbeck, L. von Smekal, A. G. Williams, and J.-b. Zhang, “Scaling behavior and positivity violation of the gluon propagator in full QCD,”Phys. Rev. D76(2007) 094505,hep-lat/0703022. 47

  78. [78]

    Two-point functions and bootstrap applications in quantum field theories,

    D. Karateev, “Two-point functions and bootstrap applications in quantum field theories,”JHEP02(2022) 186,2012.08538

  79. [79]

    Extrapolating the massive fields to future timelike infinity,

    W.-B. Liu and J. Long, “Extrapolating the massive fields to future timelike infinity,” JHEP12(2025) 042,2508.15619

  80. [80]

    Two-point correlators inN= 2 gauge theories,

    M. Billo, F. Fucito, A. Lerda, J. F. Morales, Y. S. Stanev, and C. Wen, “Two-point correlators inN= 2 gauge theories,”Nucl. Phys. B926(2018) 427–466,1705.02909

Showing first 80 references.