Pith. sign in

REVIEW 2 major objections 4 minor 54 references

In d>4 massive scalar QED the one-loop soft-photon amplitude contains a universal, factorizing term of order ω^{d−4} ln ω despite the infrared-finite S-matrix; its classical counterpart is a universal retarded-time waveform tail.

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 →

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

In d>4, soft photon emission acquires a universal omega^{d-4} ln omega factor, producing power-law early- and late-time radiative tails in the classical electromagnetic waveform.

T0 review reviewed 2026-08-05 challenge →

load-bearing objection A careful scalar-QED calculation of higher-dimensional logarithmic soft photons that looks right within its stated setup, but the advertised 'universal theorem' is broader than what is proven. the 2 major comments →

arxiv 2608.03747 v1 pith:FMSRMCYR submitted 2026-08-04 hep-th gr-qchep-ph

Logarithmic Soft Photon Theorem and Waveform Tails in Higher Dimensions

Biswajit Sahoo This is my paper
classification hep-th gr-qchep-ph
keywords soft photon theoremlogarithmic soft theoremhigher-dimensional QEDelectromagnetic waveform tailstail memorymassive scalar QEDretarded Green's function
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.

The reading

In four spacetime dimensions, logarithmic corrections to the soft-photon theorem are tied to infrared divergences. This paper asks whether such a logarithm survives in d>4, where the massive charged-particle S-matrix in QED is infrared finite. Its answer is yes: a direct one-loop calculation in massive scalar QED finds a factorizing, gauge-invariant soft term of order ω^{d−4} ln ω, with explicit even- and odd-dimensional coefficients, generated by the long-range Coulomb force acting on asymptotic trajectories. The same long-range acceleration produces, at leading radiative order, universal electromagnetic waveform tails: |u|^{−(3d−10)/2} in even d≥6 and ln u/u^{(3d−10)/2}, plus |u|^{−(3d−10)/2}, in odd d≥5. If true, logarithmic soft behavior and tail memory are not artefacts of infrared divergence; they are generic consequences of long-range interactions in any dimension.

Core claim

The central claim is that the long-range electromagnetic interaction produces a non-analytic, factorizing logarithmic contribution at order ω^{d−4} ln ω in the d>4 one-loop soft-photon amplitude, and the corresponding universal tail in the retarded classical waveform, despite the infrared-finite S-matrix. The logarithm is selected by the scale-invariant loop-momentum region ω≪|ℓ|≪Λ, i.e. by the (d−4)-th term in expanding a charged-particle propagator next to the emitted photon. The paper evaluates the coefficient exactly for scalar QED: a matter-pole term and a photon-pole term per ordered pair of hard lines, given by finite even-dimensional series plus an inverse hyperbolic cosine, and by a

What carries the argument

The load-bearing object is the logarithmic soft factor S^{ln}_{em}(ε,k), the coefficient of ω^{d−4} ln ω. It is extracted from a scalar Feynman master integral K^F_{ab}, integrated over the scale-invariant shell ω≪|ℓ|≪Λ with a photon propagator and one hard propagator raised to power d−3; its matter-pole residue gives one term and its photon-pole residue the other, with coefficient functions C_d and H_d(s). On the classical side the same structure is carried by the acceleration-induced current J^μ_acc(k), built from the long-range trajectory corrections, whose proper-time integral yields ln(ω±iϵ) with the sign fixed by outgoing or incoming support. The even-dimensional case localizes the tai

Load-bearing premise

The argument assumes that the details of the hard-scattering region and of each particle's radiation back-reaction can only change analytic (power-series) parts of the low-frequency answer—if they also produced a piece proportional to ω^{d−4} ln ω, the claimed universal coefficient would fail.

What would settle it

Compute the same one-loop logarithmic coefficient in d=5 massive scalar QED with a derivative (non-minimal) hard interaction, or with external fermions: if the coefficient of ω ln ω changes, universality fails. Classically, integrate the retarded two-charge scattering equations in d=5 numerically out to large retarded time and fit the late waveform to A ln u/u^{5/2} + B/u^{5/2}; agreement with the paper's coefficient sum C_out,odd + C_mix,odd + C_in,odd would confirm the prediction, and any additional non-analytic term at that order would refute it.

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

If this is right

  • For even d≥6, the straight-line radiative waveform at leading order is supported only in a retarded-time window of size R and produces no persistent memory; the acceleration term creates universal early- and late-time tails |u|^{−(3d−10)/2}, i.e. tail memory without kick memory.
  • For odd d≥5, even straight-line motion produces a u^{−(d−4)/2} late-time tail, and the acceleration term adds a logarithmically enhanced ln u/u^{(3d−10)/2} late tail plus a |u|^{−(3d−10)/2} early tail, the late coefficient fixed by three universal coefficient vectors including a mixed incoming-to-outgoing term.
  • The one-loop logarithmic soft factor factorizes against the non-radiative amplitude, S^{ln}_{em} M^{(0)}_n, and is gauge invariant pair by pair; the authors expect it to be universal and one-loop exact, extending the four-dimensional result.
  • In even dimensions the classical retarded soft factor is exactly the matter-pole part of the quantum factor; in odd dimensions the separable retarded part contains outgoing, incoming and mixed causal orderings, with the reverse ordering vanishing by retarded causality.
  • The same region analysis and prescription comparison should yield a gravitational counterpart: an ω^{d−4} ln ω soft-graviton factor and its associated waveform tails, as the outlook states.

Where Pith is reading between the lines

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

  • Because the logarithm arises without any infrared pole, nothing in the present calculation forbids higher-loop terms of order ω^{d−4}(ln ω)^n; a two-loop check in the same scalar-QED setup would test the one-loop-exactness claim directly.
  • The even/odd distinction—no memory in even d, persistent power-law and log tails in odd d—suggests that long-time tail memory could serve as a dimensional probe: resolving the exponent and sign of the tail could in principle distinguish even from odd spacetime dimension.
  • The mixed incoming-to-outgoing term in odd dimensions means an observer's late-time waveform carries information about the initial state through timelike separations; this could be used as a diagnostic of the causal propagation structure of the theory.
  • The finite closed-form series structure of the coefficients suggests the gravitational analogue may also terminate polynomially in d, making the higher-dimensional log-graviton computation tractable in closed form.
Share X Bluesky LinkedIn Reddit HN

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 / 4 minor

Summary. The paper derives a one-loop logarithmic soft-photon contribution in massive scalar QED in d>4 spacetime dimensions, showing that the amplitude contains a factorizing, gauge-invariant term of order ω^{d−4} lnω even though the charged-particle S-matrix is infrared finite. The logarithm is traced to the scale-invariant loop-momentum region ω ≪ |ℓ| ≪ Λ. Explicit even- and odd-dimensional coefficients are given in Eqs. (1.4)/(3.31), and a classical counterpart is constructed from the long-range acceleration of asymptotic trajectories, yielding universal retarded-time tails in Eqs. (1.17)–(1.19). The paper also compares Feynman and retarded boundary conditions to separate the classical radiative part from an intrinsically quantum remainder, and includes independent position-space, contour, and proper-time checks.

Significance. If the one-loop scalar QED result and the classical waveform computation hold, this is a substantial extension of logarithmic soft theorems beyond d=4, where no infrared pole is available to explain the logarithm. The paper's strengths are its explicitness: parameter-free coefficients, detailed contour evaluations in Appendices B and C, an independent position-space derivation in Section 2.4, and consistency checks such as the d=4 limit reproducing the known result of [31]. The main weakness is scope: the advertised universal logarithmic soft-photon theorem is proven only for one-loop scalar QED with minimal couplings, and the paper itself states that spin, non-minimal couplings, and higher loops require further work. The central technical calculation appears sound, but the presentation overstates the generality of the theorem.

major comments (2)
  1. [Abstract and Section 1, after Eq. (1.4); also Section 4] The abstract and title advertise a universal logarithmic soft-photon theorem in d>4, and Eq. (1.3)/(1.4) is displayed as the general soft factor. However, the derivation is explicitly restricted to one loop in scalar QED with a non-derivative contact interaction (Lagrangian (3.4)). The text itself says 'we expect' universality and one-loop exactness, but that 'a proof requires extending the calculation to general spins and gauge-invariant non-minimal couplings, together with control over higher-loop corrections.' This is a load-bearing scope gap: if a fermion magnetic-dipole coupling or a derivative interaction contributes at the same ω^{d−4} lnω order, the coefficient is process-dependent and the theorem as stated is false. The paper should either prove universality in the stated generality or consistently reframe the central claim as a one-loop scalar QED result, changing the abstract,
  2. [Section 2.1 and 2.3.1, Eq. (2.32), Eq. (2.39)] The classical waveform coefficients are presented as universal, but the derivation assumes that the compactly supported hard-region current is analytic (which is justified) and that trajectory corrections can be linearized, with O(Y^2) and self-force effects neglected. The paper gives a clear power-counting and moment argument for the subleading trajectory tail in Appendix B.2, but it does not provide an equally explicit argument that the O(Y^2) terms in Eq. (2.32) or self-force/radiation-reaction corrections are suppressed in the same expansion that selects the ω^{d−4} lnω term. If these omissions are justified by an expansion in powers of the charge, that parameter should be stated explicitly; otherwise the 'universal' classical tail claim is incomplete. This is a corrigible gap, but it is load-bearing for the classical half of the paper.
minor comments (4)
  1. [Throughout] The symbol ≃ is used with several different meanings: dropping little-o radiative remainders, truncating the current expansion, discarding non-logarithmic terms, and equality in the large-|u| hierarchy. Although each use is locally defined, a global summary of the convention would improve readability.
  2. [Eq. (1.4) and text below it] The notation lnω is dimensionally awkward; the text correctly explains that it means ln(ω/Λ). Consider writing ln(ω/Λ) explicitly in the display equations to avoid confusion.
  3. [Appendix C heading] Typographical issue: 'F eynman' should be 'Feynman'. There are also minor spacing inconsistencies such as 'd >4' in the abstract.
  4. [Section 2.2, Eq. (2.24)] The phrase 'derivative of a delta function' could be made more precise by explicitly noting the order (d−6)/2 and the distributional sense in which the support statement holds; this is implicit but would help readers.

Circularity Check

0 steps flagged

No significant circularity: the d>4 logarithmic coefficient is computed from explicit Feynman and retarded-field integrals, not taken as an input or fitted parameter.

full rationale

The central claims are derived from first principles within the paper rather than imported from prior work. Classically, the logarithmic waveform follows from the explicit current (2.4) with straight-line and acceleration-induced pieces, the radiative kernel (2.13), and a momentum-region analysis (2.44)-(2.49) that selects the unique d-4 logarithmic marginality condition; the resulting integrals are evaluated in Appendix B and independently checked in position space in Section 2.4 and by the proper-time argument in Appendix B.2. Quantum mechanically, the one-loop scalar QED diagrams (3.7)-(3.9) are reduced in the logarithmic region (3.12) to the scalar master integral (C.23), whose evaluation gives the soft factor (3.31) and the one-loop theorem (3.32). No parameter is fitted to a target quantity, and the result is not defined in terms of the quantity it predicts. Self-citations appear only as consistency checks or methodological templates: the d=4 limit of (C.23) is compared with I_ab of [31], the position-space localization borrows a technique from [52], and [35] is cited only in the expectation of universality, not as an input determining the new coefficient. The paper's own caveat that proving full universality requires extending the calculation to general spins, non-minimal couplings, and higher loops (Section 1 and Section 4) is a scope limitation, not circularity: it does not make the scalar-QED derivation depend on its conclusion. Under the review rules, this merits a low score on the circularity axis.

Axiom & Free-Parameter Ledger

0 free parameters · 6 axioms · 0 invented entities

No fitted parameters appear: all quantities are the physical scattering data (masses, charges, momenta) and the dimensionful scales R and Lambda defined by the setup. No new particles, forces, conserved charges, or dimensions are introduced; the 'mixed' odd-dimensional term is an existing causal contribution of the retarded Green's function, not a new entity. The load-bearing assumptions are the analyticity of the compact-region contribution and the linearization of trajectory corrections, both stated explicitly.

axioms (6)
  • domain assumption The hard interaction is confined to a compact region of size R; the compactly supported part of the current has a Fourier transform that is analytic for |omega| R << 1.
    Section 2.1: this analyticity is what makes the logarithmic coefficient universal rather than process dependent, and it is a load-bearing premise for the classical derivation.
  • domain assumption Generic massive kinematics: no two distinct particles on the same asymptotic branch have identical four-velocity, so all relative-velocity invariants are nonzero.
    Stated in Section 1 and Section 2.1; denominators such as (pa.pb)^2 - pa^2 pb^2 are assumed nonzero throughout.
  • domain assumption Trajectory corrections are computed to leading order in the long-range interaction: the force is evaluated on straight-line trajectories, and radiation reaction, self-force effects and O(Y^2) terms are neglected.
    Equation (2.32) and Section 2.3.1: the claimed universality relies on these neglected terms not contaminating the omega^{d-4} ln omega coefficient, defended only by the moment argument in Appendix B.2.
  • domain assumption The quantum calculation uses massive scalar QED with a non-derivative contact hard interaction in Feynman gauge.
    Section 3.1, Lagrangian (3.4): the one-loop theorem is derived in this specific theory; extension to spins and non-minimal couplings is left open.
  • domain assumption The observer hierarchy r^{-1} << |omega| << R^{-1} and R << |u| << r selects the radiation-zone saddle point and the large-retarded-time window.
    Equations (1.15) and (2.23): all stated waveform tails are claimed valid only inside this hierarchy.
  • standard math Standard distributional Fourier transforms, gamma-function identities and hypergeometric function identities are used in Appendices A-C.
    The evaluations of branch-sensitive Fourier integrals (Appendix A), the acceleration momentum integrals (Appendix B), and the Feynman master integral (Appendix C) rely on these standard results.

reviewed 2026-08-05 · how reviews work

0 comments
Cite this review

Pith. "Pith review of Logarithmic Soft Photon Theorem and Waveform Tails in Higher Dimensions." pith.science (2026). https://pith.science/paper/FMSRMCYR

@misc{pith2026260803747,
  author       = {Pith},
  title        = {Pith review of: Logarithmic Soft Photon Theorem and Waveform Tails in Higher Dimensions},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/FMSRMCYR}},
  note         = {Machine review of arXiv:2608.03747}
}
Share X Bluesky LinkedIn Reddit HN
abstract

We derive the leading logarithmic soft-photon theorem in $d>4$ spacetime dimensions and its classical radiative counterpart. A direct one-loop analysis in massive scalar quantum electrodynamics (QED) yields a factorizing soft term of order $\omega^{d-4}\ln\omega$, although the charged-particle S-matrix is infrared finite. The logarithm is generated by the scale-invariant loop-momentum region $\omega\ll|\ell|\ll\Lambda$, where $\Lambda$ denotes a characteristic hard-particle energy scale. At leading radiative order, the corresponding logarithmic contribution to the classical electromagnetic waveform arises from the long-range acceleration of the asymptotic charged particles. In even $d\geq6$, the straight-line waveform at this radiative order is distributionally supported in retarded time within an interval whose width is set by the characteristic size of the hard-scattering region, whereas the logarithmic acceleration term produces universal early- and late-time radiative tails proportional to $|u|^{-(3d-10)/2}$. In odd $d\geq5$, straight-line motion already gives a late-time tail at the same radiative order proportional to $u^{-(d-4)/2}$. The acceleration correction adds universal late- and early-time terms proportional, respectively, to $\ln u/u^{(3d-10)/2}$ and $|u|^{-(3d-10)/2}$. A comparison of Feynman and retarded boundary conditions separates the classically radiative contribution from the intrinsically quantum part of the logarithmic soft factor.

discussion (0)

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

Reference graph

Works this paper leans on

54 extracted references · 12 canonical work pages · 6 internal anchors

  1. [1]

    Scattering of Light of Very Low Frequency by Systems of Spin One-Half,

    F. E. Low, “Scattering of Light of Very Low Frequency by Systems of Spin One-Half,”Phys. Rev.96(1954) 1428–1432, doi:10.1103/PhysRev.96.1428

    doi:10.1103/physrev.96.1428 1954

  2. [2]

    Scattering of Low-Energy Photons by Particles of Spin One-Half,

    M. Gell-Mann and M. L. Goldberger, “Scattering of Low-Energy Photons by Particles of Spin One-Half,”Phys. Rev.96(1954) 1433–1438, doi:10.1103/PhysRev.96.1433

    work page doi:10.1103/physrev.96.1433 1954

  3. [3]

    Bremsstrahlung of Very Low-Energy Quanta in Elementary Particle Collisions,

    F. E. Low, “Bremsstrahlung of Very Low-Energy Quanta in Elementary Particle Collisions,” Phys. Rev.110(1958) 974–977, doi:10.1103/PhysRev.110.974. – 65 –

    doi:10.1103/physrev.110.974 1958

  4. [4]

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

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

    doi:10.1103/physrev.135.b1049 1964

  5. [5]

    Infrared Photons and Gravitons,

    S. Weinberg, “Infrared Photons and Gravitons,”Phys. Rev.140(1965) B516–B524, doi:10.1103/PhysRev.140.B516

    doi:10.1103/physrev.140.b516 1965

  6. [6]

    Extension of the Low Soft-Photon Theorem,

    T. H. Burnett and N. M. Kroll, “Extension of the Low Soft-Photon Theorem,”Phys. Rev. Lett. 20(1968) 86–88, doi:10.1103/PhysRevLett.20.86

    work page doi:10.1103/physrevlett.20.86 1968

  7. [7]

    On the Low-Burnett-Kroll Theorem for Soft-Photon Emission,

    J. S. Bell and R. Van Royen, “On the Low-Burnett-Kroll Theorem for Soft-Photon Emission,” Nuovo Cim. A60(1969) 62–68, doi:10.1007/BF02823297

    work page doi:10.1007/bf02823297 1969

  8. [8]

    Soft Photon and Graviton Theorems in Effective Field Theory,

    H. Elvang, C. R. T. Jones and S. G. Naculich, “Soft Photon and Graviton Theorems in Effective Field Theory,”Phys. Rev. Lett.118(2017) no.23, 231601, doi:10.1103/PhysRevLett.118.231601 [arXiv:1611.07534 [hep-th]]

    Pith/arXiv arXiv 2017

  9. [9]

    An Electromagnetic Analogue of Gravitational Wave Memory,

    L. Bieri and D. Garfinkle, “An Electromagnetic Analogue of Gravitational Wave Memory,” Class. Quant. Grav.30(2013) 195009, doi:10.1088/0264-9381/30/19/195009 [arXiv:1307.5098 [gr-qc]]

    Pith/arXiv arXiv 2013

  10. [10]

    Retarded Fields of Null Particles and the Memory Effect,

    A. Tolish and R. M. Wald, “Retarded Fields of Null Particles and the Memory Effect,”Phys. Rev. D89(2014) no.6, 064008, doi:10.1103/PhysRevD.89.064008 [arXiv:1401.5831 [gr-qc]]

    Pith/arXiv arXiv 2014

  11. [11]

    Electromagnetic Memory,

    L. Susskind, “Electromagnetic Memory,” [arXiv:1507.02584 [hep-th]]

    Pith/arXiv arXiv

  12. [12]

    New Symmetries of Massless QED,

    T. He, P. Mitra, A. P. Porfyriadis and A. Strominger, “New Symmetries of Massless QED,” JHEP10(2014) 112, doi:10.1007/JHEP10(2014)112 [arXiv:1407.3789 [hep-th]]

    Pith/arXiv arXiv 2014

  13. [13]

    Asymptotic Symmetries of Massless QED in Even Dimensions,

    D. Kapec, V. Lysov and A. Strominger, “Asymptotic Symmetries of Massless QED in Even Dimensions,”Adv. Theor. Math. Phys.21(2017) 1747–1767, doi:10.4310/ATMP.2017. v21.n7.a6 [arXiv:1412.2763 [hep-th]]

    Pith/arXiv arXiv 2017

  14. [14]

    Asymptotic Symmetries and Electromagnetic Memory,

    S. Pasterski, “Asymptotic Symmetries and Electromagnetic Memory,”JHEP09(2017) 154, doi:10.1007/JHEP09(2017)154 [arXiv:1505.00716 [hep-th]]

    Pith/arXiv arXiv 2017

  15. [15]

    Asymptotic Symmetries of QED and Weinberg’s Soft Photon Theorem,

    M. Campiglia and A. Laddha, “Asymptotic Symmetries of QED and Weinberg’s Soft Photon Theorem,”JHEP07(2015) 115, doi:10.1007/JHEP07(2015)115 [arXiv:1505.05346 [hep-th]]

    Pith/arXiv arXiv 2015

  16. [16]

    New Symmetries of QED,

    D. Kapec, M. Pate and A. Strominger, “New Symmetries of QED,”Adv. Theor. Math. Phys. 21(2017) 1769–1785, doi:10.4310/ATMP.2017.v21.n7.a7 [arXiv:1506.02906 [hep-th]]

    Pith/arXiv arXiv 2017

  17. [17]

    Asymptotic Symmetries and Weinberg’s Soft Photon Theorem in Minkd+2,

    T. He and P. Mitra, “Asymptotic Symmetries and Weinberg’s Soft Photon Theorem in Minkd+2,”JHEP10(2019) 213, doi:10.1007/JHEP10(2019)213 [arXiv:1903.02608 [hep-th]]

    Pith/arXiv arXiv 2019

  18. [18]

    New Electromagnetic Memories and Soft Photon Theorems,

    P. Mao, H. Ouyang, J.-B. Wu and X. Wu, “New Electromagnetic Memories and Soft Photon Theorems,”Phys. Rev. D95(2017) no.12, 125011, doi:10.1103/PhysRevD.95.125011 [arXiv:1703.06588 [hep-th]]

    Pith/arXiv arXiv 2017

  19. [19]

    Notes on the Gravitational, Electromagnetic and Axion Memory Effects,

    Y. Hamada and S. Sugishita, “Notes on the Gravitational, Electromagnetic and Axion Memory Effects,”JHEP07(2018) 017, doi:10.1007/JHEP07(2018)017 [arXiv:1803.00738 [hep-th]]

    Pith/arXiv arXiv 2018

  20. [20]

    Electromagnetic and Color Memory in Even Dimensions,

    A. Campoleoni, D. Francia and C. Heissenberg, “Electromagnetic and Color Memory in Even Dimensions,”Phys. Rev. D100(2019) no.8, 085015, doi:10.1103/PhysRevD.100.085015 [arXiv:1907.05187 [hep-th]]

    Pith/arXiv arXiv 2019

  21. [21]

    Radiation and the classical double copy for color charges,

    W. D. Goldberger and A. K. Ridgway, “Radiation and the classical double copy for color charges,”Phys. Rev. D95(2017) no.12, 125010, doi:10.1103/PhysRevD.95.125010 [arXiv:1611.03493 [hep-th]]. – 66 –

    Pith/arXiv arXiv 2017

  22. [22]

    Amplitudes, Observables, and Classical Scattering,

    D. A. Kosower, B. Maybee and D. O’Connell, “Amplitudes, Observables, and Classical Scattering,”JHEP02(2019) 137, doi:10.1007/JHEP02(2019)137 [arXiv:1811.10950 [hep-th]]

    Pith/arXiv arXiv 2019

  23. [23]

    Gravity Waves from Soft Theorem in General Dimensions,

    A. Laddha and A. Sen, “Gravity Waves from Soft Theorem in General Dimensions,”JHEP09 (2018) 105, doi:10.1007/JHEP09(2018)105 [arXiv:1801.07719 [hep-th]]

    Pith/arXiv arXiv 2018

  24. [24]

    From Scattering Amplitudes to Classical Physics: Universality, Double Copy and Soft Theorems

    Y. F. Bautista and A. Guevara, “From Scattering Amplitudes to Classical Physics: Universality, Double Copy and Soft Theorems,” [arXiv:1903.12419 [hep-th]]

    work page internal anchor Pith review Pith/arXiv arXiv 1903

  25. [25]

    A Classical Proof of the Classical Soft Graviton Theorem in D>4

    A. Laddha and A. Sen, “Classical proof of the classical soft graviton theorem inD >4,”Phys. Rev. D101(2020) no.8, 084011, doi:10.1103/PhysRevD.101.084011 [arXiv:1906.08288 [gr-qc]]

    work page internal anchor Pith review Pith/arXiv arXiv 2020

  26. [26]

    Soft Radiation from Scattering Amplitudes Revisited,

    A. Manu, D. Ghosh, A. Laddha and P. V. Athira, “Soft Radiation from Scattering Amplitudes Revisited,”JHEP05(2021) 056, doi:10.1007/JHEP05(2021)056 [arXiv:2007.02077 [hep-th]]

    Pith/arXiv arXiv 2021

  27. [27]

    Large Deflection Scattering, Soft Radiation and KMOC Formalism,

    S. Akhtar, A. Laddha, A. Manna and A. Manu, “Large Deflection Scattering, Soft Radiation and KMOC Formalism,” [arXiv:2511.17204 [hep-th]]

    arXiv

  28. [28]

    Log Soft Constraints on the Kosower-Maybee-O’Connell Formalism,

    S. Paul and A. Vishwakarma, “Log Soft Constraints on the Kosower-Maybee-O’Connell Formalism,”Phys. Rev. D, in press (2026), doi:10.1103/3p3j-rw7y [arXiv:2601.00336 [hep-th]]

    work page arXiv 2026

  29. [29]

    Logarithmic Terms in the Soft Expansion in Four Dimensions,

    A. Laddha and A. Sen, “Logarithmic Terms in the Soft Expansion in Four Dimensions,”JHEP 10(2018) 056, doi:10.1007/JHEP10(2018)056 [arXiv:1804.09193 [hep-th]]

    Pith/arXiv arXiv 2018

  30. [30]

    Observational Signature of the Logarithmic Terms in the Soft-Graviton Theorem,

    A. Laddha and A. Sen, “Observational Signature of the Logarithmic Terms in the Soft-Graviton Theorem,”Phys. Rev. D100(2019) no.2, 024009, doi:10.1103/PhysRevD.100.024009 [arXiv:1806.01872 [hep-th]]

    Pith/arXiv arXiv 2019

  31. [31]

    Classical and Quantum Results on Logarithmic Terms in the Soft Theorem in Four Dimensions,

    B. Sahoo and A. Sen, “Classical and Quantum Results on Logarithmic Terms in the Soft Theorem in Four Dimensions,”JHEP02(2019) 086, doi:10.1007/JHEP02(2019)086 [arXiv:1808.03288 [hep-th]]

    Pith/arXiv arXiv 2019

  32. [32]

    Proof of the classical soft graviton theorem inD= 4,

    A. P. Saha, B. Sahoo and A. Sen, “Proof of the classical soft graviton theorem inD= 4,” JHEP06(2020) 153, doi:10.1007/JHEP06(2020)153 [arXiv:1912.06413 [hep-th]]

    Pith/arXiv arXiv 2020

  33. [33]

    Classical Sub-subleading Soft Photon and Soft Graviton Theorems in Four Spacetime Dimensions,

    B. Sahoo, “Classical Sub-subleading Soft Photon and Soft Graviton Theorems in Four Spacetime Dimensions,”JHEP12(2020) 070, doi:10.1007/JHEP12(2020)070 [arXiv:2008.04376 [hep-th]]

    Pith/arXiv arXiv 2020

  34. [34]

    New Asymptotic Conservation Laws for Electromagnetism,

    S. A. Bhatkar, “New Asymptotic Conservation Laws for Electromagnetism,”JHEP02(2021) 082, doi:10.1007/JHEP02(2021)082 [arXiv:2007.03627 [hep-th]]

    Pith/arXiv arXiv 2021

  35. [35]

    Universality of Loop Corrected Soft Theorems in 4d,

    H. Krishna and B. Sahoo, “Universality of Loop Corrected Soft Theorems in 4d,”JHEP11 (2023) 233, doi:10.1007/JHEP11(2023)233 [arXiv:2308.16807 [hep-th]]

    Pith/arXiv arXiv 2023

  36. [36]

    Electromagnetic Multipole Expansions and the Logarithmic Soft Photon Theorem,

    G. Compère, D. Fontaine and K. Nguyen, “Electromagnetic Multipole Expansions and the Logarithmic Soft Photon Theorem,”SciPost Phys. Core8(2025) no.4, 066, doi:10.21468/SciPostPhysCore.8.4.066 [arXiv:2503.23937 [hep-th]]

    arXiv 2025

  37. [37]

    Loop Corrected Soft Photon Theorem as a Ward Identity,

    M. Campiglia and A. Laddha, “Loop Corrected Soft Photon Theorem as a Ward Identity,” JHEP10(2019) 287, doi:10.1007/JHEP10(2019)287 [arXiv:1903.09133 [hep-th]]

    Pith/arXiv arXiv 2019

  38. [38]

    Ward identity for loop level soft photon theorem for massless QED coupled to gravity

    S. A. Bhatkar, “Ward identity for loop level soft photon theorem for massless QED coupled to gravity,”JHEP10(2020) 110, doi:10.1007/JHEP10(2020)110 [arXiv:1912.10229 [hep-th]]

    work page internal anchor Pith review Pith/arXiv arXiv 2020

  39. [39]

    Asymptotic Symmetries for Logarithmic Soft Theorems in Gauge Theory and Gravity,

    S. Choi, A. Laddha and A. Puhm, “Asymptotic Symmetries for Logarithmic Soft Theorems in Gauge Theory and Gravity,” [arXiv:2403.13053 [hep-th]]. – 67 –

    Pith/arXiv arXiv

  40. [40]

    Logarithmic soft graviton theorems from superrotation Ward identities,

    S. Agrawal, L. Donnay, K. Nguyen and R. Ruzziconi, “Logarithmic soft graviton theorems from superrotation Ward identities,”JHEP02(2024) 120, doi:10.1007/JHEP02(2024)120 [arXiv:2309.11220 [hep-th]]

    Pith/arXiv arXiv 2024

  41. [41]

    The Classical Super-Phaserotation Infrared Triangle. Classical Logarithmic Soft Theorem as Conservation Law in (Scalar) QED,

    S. Choi, A. Laddha and A. Puhm, “The Classical Super-Phaserotation Infrared Triangle. Classical Logarithmic Soft Theorem as Conservation Law in (Scalar) QED,”JHEP05(2025) 155, doi:10.1007/JHEP05(2025)155 [arXiv:2412.16149 [hep-th]]

    arXiv 2025

  42. [42]

    All-loop Soft-Photon Theorems and Higher Spin Currents on the Celestial Sphere,

    S. Banerjee, R. Mandal and B. Sahoo, “All-loop Soft-Photon Theorems and Higher Spin Currents on the Celestial Sphere,”Phys. Rev. D114(2026) no.2, L021903, doi:10.1103/ypp6-3nyh [arXiv:2601.03361 [hep-th]]

    arXiv 2026

  43. [43]

    Long-Range Interactions in Celestial CFT,

    S. Choi, A. Kadhe and A. Puhm, “Long-Range Interactions in Celestial CFT,” [arXiv:2601. 05951 [hep-th]]

    work page

  44. [44]

    The Memory Effect for Particle Scattering in Even Spacetime Dimensions

    D. Garfinkle, S. Hollands, A. Ishibashi, A. Tolish and R. M. Wald, “The Memory Effect for Particle Scattering in Even Spacetime Dimensions,”Class. Quant. Grav.34(2017) no.14, 145015, doi:10.1088/1361-6382/aa777b [arXiv:1702.00095 [gr-qc]]

    work page internal anchor Pith review Pith/arXiv arXiv 2017

  45. [45]

    Memory effect for particle scattering in odd spacetime dimensions,

    G. Satishchandran and R. M. Wald, “Memory effect for particle scattering in odd spacetime dimensions,”Phys. Rev. D97(2018) no.2, 024036, doi:10.1103/PhysRevD.97.024036 [arXiv:1712.00873 [gr-qc]]

    Pith/arXiv arXiv 2018

  46. [46]

    Infinite Set of Soft Theorems in Gauge-Gravity Theories as Ward-Takahashi Identities,

    Y. Hamada and G. Shiu, “Infinite Set of Soft Theorems in Gauge-Gravity Theories as Ward-Takahashi Identities,”Phys. Rev. Lett.120(2018) no.20, 201601, doi:10.1103/PhysRevLett.120.201601 [arXiv:1801.05528 [hep-th]]

    Pith/arXiv arXiv 2018

  47. [47]

    Infinite Soft Theorems from Gauge Symmetry,

    Z.-Z. Li, H.-H. Lin and S.-Q. Zhang, “Infinite Soft Theorems from Gauge Symmetry,”Phys. Rev. D98(2018) no.4, 045004, doi:10.1103/PhysRevD.98.045004 [arXiv:1802.03148 [hep-th]]

    Pith/arXiv arXiv 2018

  48. [48]

    Asymptotic charges in massless QED revisited: A view from spatial infinity,

    M. Campiglia and A. Laddha, “Asymptotic charges in massless QED revisited: A view from spatial infinity,”JHEP05(2019) 207, doi:10.1007/JHEP05(2019)207 [arXiv:1810.04619 [hep-th]]

    Pith/arXiv arXiv 2019

  49. [49]

    Spin Dependent Gravitational Tail Memory in $D=4$

    D. Ghosh and B. Sahoo, “Spin-Dependent Gravitational Tail Memory inD = 4,”Phys. Rev. D 105(2022) no.2, 025024, doi:10.1103/PhysRevD.105.025024 [arXiv:2106.10741 [hep-th]]

    work page internal anchor Pith review Pith/arXiv arXiv 2022

  50. [50]

    2PM waveform from loop corrected soft theorems,

    F. Alessio and P. Di Vecchia, “2PM waveform from loop corrected soft theorems,”J. Phys. A 57(2024) no.47, 475402, doi:10.1088/1751-8121/ad8b02 [arXiv:2402.06533 [hep-th]]

    Pith/arXiv arXiv 2024

  51. [51]

    Improved Treatment for the Infrared-Divergence Problem in Quantum Electrodynamics,

    G. Grammer, Jr. and D. R. Yennie, “Improved Treatment for the Infrared-Divergence Problem in Quantum Electrodynamics,”Phys. Rev. D8(1973) 4332–4344, doi:10.1103/PhysRevD.8.4332

    work page doi:10.1103/physrevd.8.4332 1973

  52. [52]

    All Order Classical Electromagnetic Soft Theorems,

    D. Karan, B. Khatun, B. Sahoo and A. Sen, “All Order Classical Electromagnetic Soft Theorems,”JHEP11(2025) 025, doi:10.1007/JHEP11(2025)025 [arXiv:2501.07328 [hep-th]]

    Pith/arXiv arXiv 2025

  53. [53]

    Asymptotic Symmetries in $(d+2)$-Dimensional Gauge Theories

    T. He and P. Mitra, “Asymptotic Symmetries in(d + 2)-Dimensional Gauge Theories,”JHEP 10(2019) 277, doi:10.1007/JHEP10(2019)277 [arXiv:1903.03607 [hep-th]]

    work page internal anchor Pith review Pith/arXiv arXiv 2019

  54. [54]

    New Magnetic Symmetries in(d+ 2)-Dimensional QED,

    T. He and P. Mitra, “New Magnetic Symmetries in(d+ 2)-Dimensional QED,”JHEP01 (2021) 122, doi:10.1007/JHEP01(2021)122 [arXiv:1907.02808 [hep-th]]. – 68 –

    Pith/arXiv arXiv 2021

This paper was first reviewed by deepseek-v4-flash on August 5, 2026.