Pith. sign in

REVIEW 3 major objections 5 minor 106 references

Soft Factorisation and Exponentiation from Schwinger-Space Geometry

T0 review · 3 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read This paper derives soft-hard factorisation and all-loop exponentiation of infrared divergences in massive QED from the tropical geometry of Schwinger parameters and graph Laplacians.

desk verdict A genuinely new Schwinger-space proof of QED exponentiation whose main gap—the unproved completeness of the ray classification—is admitted by the authors themselves. read the letter →

arxiv 2506.15603 v1 pith:K7AERQO7 submitted 2025-06-18 hep-th hep-ph

classification hep-thhep-ph
keywords infrareddivergencesSchwingerparametrizationtropicalgeometrygraphLaplacianfactorisationexponentiationQEDsoftfunctionworldlinevariables
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper tries to establish, directly in Schwinger-parameter space, that the infrared structure of massive QED amplitudes is completely captured by a factorised and exponentiated form: the amplitude is a hard factor times the exponential of a one-loop soft integral, $A = H \exp(\int dS^{(1)})$. The authors first use tropical geometry to identify which scalings of Schwinger parameters produce infrared divergences, then show that under those scalings the graph Laplacian decomposes into hard and soft blocks, so the integrand factorises as $dI \simeq dI_H \prod_W dI_W$. A key step is that, when written in worldline-distance variables $\beta_{j,k} = \sum_{h\le k}\alpha_{j,h}$, planar and non-planar ladder diagrams have the same soft integrand and differ only in their integration regions; summing over diagrams tiles the full integration space and produces the $1/\ell!$ factors that convert a sum into an exponential. If this is correct, every higher-loop infrared pole in massive QED is fixed by one-loop information, and the same geometric language supplies a local all-order subtraction scheme for infrared divergences.

What carries the argument

The central object is the reduced graph Laplacian $L$ (the graph Laplacian with one hard vertex removed) together with the weighted incidence matrix $M$ used to include numerator factors. The Schwinger integrand is written as $(\prod_e d\alpha_e)/(\prod_e \alpha_e^{D/2}(\det L)^{D/2}) \exp(iV(z))$, with the modified worldline action $V(z) = (p + \tfrac{i}{2}Mz)^T L^{-1}(p + \tfrac{i}{2}Mz) + \sum_e z_e^2/(4\alpha_e) - \sum_e m_e^2\alpha_e$. Under a soft scaling the matrix $L$ splits into blocks $H$, $J$, $B$ and photon blocks $\Gamma$; the jet blocks $J_i$ are tridiagonal and their inverses are exactly the worldline-distance matrices $(J_i^{-1})_{v,v'} = \beta_{i,\min(v,v')}$, which is what makes the soft action a sum of one-loop dipole exchanges and makes the integrand independent of the ordering of photon attachments. Factorisation of $\det L$ and of $V(z)$ then implies integrand factorisation $dI \simeq dI_H \prod_W dI_W$, with each connected web $W$ contributing a one-loop-like soft integrand.

What would settle it

Compute the complete set of Landau-singular and boundary soft regions for the three-loop massive QED form factor and compare the predicted $1/\epsilon^k$ poles from $H\exp(\int dS^{(1)})$ with a direct evaluation of all contributing diagrams: any pole not reproduced by the exponentiated one-loop answer, or any divergent region whose ray is not of the form (0,1,2), would falsify the central claim.

Watch

Extended reading notes

Core claim

The central claim is an all-loop, integrand-level derivation of abelian soft exponentiation from the geometry of Schwinger parameters. On the tropical rays $r=(0,\ldots,0;1,\ldots,1;2,\ldots,2)$ (unscaled hard edges, jet edges scaling as $\lambda^{-1}$, soft massless edges as $\lambda^{-2}$), the Symanzik polynomials obey $U \simeq U_H U_S$ and $F/U \simeq F_H/U_H + F_S/U_S$; at the level of matrices this is the statement that the reduced Laplacian becomes block-diagonal and the worldline action splits into a hard term plus a sum over connected webs. In worldline variables, the soft integrand of every ladder-like diagram is identical, because the jet Schwinger parameters enter only as the distances $\beta$ from the hard vertex to the photon attachment, so the planar and non-planar ladders fill complementary halves of the $\beta$ integration domain. Summing all diagrams therefore gives $S = \exp\big(\sum_{(i,j)}\int dS^{(1)}(\beta;p_i,p_j)\big)$, and the amplitude takes the factorised form $A = H \cdot \exp\big(\int dS^{(1)}\big)$. The proof also yields explicit subtraction terms whose remainder is locally infrared finite in Schwinger-parameter space.

Load-bearing premise

The argument assumes that the only infrared-divergent scalings of any diagram are the rays in eq. (4.1) whose entries are 0, 1 and 2 for hard, jet and photon edges; the authors state that proving this list is complete for strictly on-shell amplitudes would require extending existing region-identification methods, so an unlisted soft region would leave factorisation and exponentiation incomplete.

Editorial extensions

If this is right

  • The two-loop massive QED form factor is reproduced from the exponentiated formula: planar and non-planar ladders combine to give $M^{(2)}_{\rm IR} = S^{(1)}M^{(1)} - \tfrac{1}{2}(S^{(1)})^2$, matching the expansion of $H \exp(S^{(1)})$.
  • At all loops the soft function $S = \exp(\sum_{(i,j)}\int dS^{(1)})$ contains every infrared pole, so no genuinely new soft anomalous dimension can appear beyond the one-loop answer in massive QED.
  • The subtraction construction is local in Schwinger-parameter space, giving an explicit infrared-finite remainder integrand at every loop order, with spurious ultraviolet divergences regulated without touching the worldline variables.
  • The renormalisation-group equation for the finite remainder is controlled by the QED cusp anomalous dimension; on-shell renormalisation yields the subtracted cusp function $\gamma^{\rm OS}_{\rm cusp} = \frac{\alpha_R}{4\pi}[(\beta-i\pi\theta(\beta))\coth\beta - 1]$.
  • The tropical-ray identification and matrix-block factorisation carry over to non-abelian theories, offering an algorithmic route to factorisation theorems in QCD through the same connected-web decomposition.

Reading between the lines

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

  • Inference: if the tropical-ray list is complete, the same worldline-tiling argument should predict the full subleading $1/\epsilon$ structure, not just the leading poles, in other massive abelian theories such as scalar QED and Yukawa theory; the one-loop soft integrand is theory-independent up to the eikonal numerator.
  • Inference: the connected-web decomposition of the soft action provides a Schwinger-space criterion for non-dipole correlations: a web whose reduced photon matrix $\gamma_W$ connects more than two jets through a non-trivial blob should generate quadrupole terms at three loops, giving a direct target for QCD checks.
  • Inference: because the subtraction sums in eqs. (5.13) and (5.16) are the infrared analogue of the standard ultraviolet $R$-operation read off the blown-up Newton polytope, the construction could be automated into a numerical integration scheme in which infrared divergences are subtracted before integrating in Schwinger space.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. The paper develops a Schwinger-parameter approach to infrared factorisation and exponentiation in massive QED. After identifying IR-divergent scalings through tropical geometry, the authors prove, at the level of graph Laplacians, that the integrand of a broad class of diagrams factorises along soft rays into hard and soft factors, and that the soft factor further decomposes into connected webs. When expressed in terms of worldline distance variables, topologically distinct ladder diagrams are shown to have identical soft integrands, with the differences residing only in the integration domains. Summing over attachment permutations tiles the positive orthant and yields the exponentiated soft function S = exp(sum over jet pairs of the one-loop soft integral), eq. (5.31), together with the factorised amplitude A = H × S, eq. (5.32). The paper also constructs local subtraction terms, discusses renormalisation, and derives the cusp anomalous dimension in a toy regulated model.

Significance. If the claims hold, the paper provides a novel, all-orders derivation of QED soft exponentiation directly in Schwinger space, with a geometric interpretation of the 1/n! factors that are usually obtained by symmetrising loop momenta. The matrix manipulations and the attached Mathematica notebook make the factorisation steps explicit and machine-checkable, and the two-loop planar/non-planar ladder checks are concrete. The derivation does not assume the exponentiated form and fits no free parameters, so the core logic is not circular. The framework also offers a local subtraction procedure and a potential avenue toward non-abelian generalisations, which makes the paper of interest to the hep-th and amplitudes communities. The main limitation is that the completeness of the assumed ray classification is explicitly left unproved, which directly affects the strength of the central exponentiation claim.

major comments (3)
  1. [Sec. 6 (Conclusions) and Sec. 2.1] The central claim, eqs. (5.31) and (5.32), requires that every IR-divergent Schwinger integration region for on-shell massive QED is captured by the ray class in eq. (4.1), with entries 0, 1, and 2. This completeness is not proved. The Conclusions state that because the external legs are on shell with the same mass as the internal particles, the generic-kinematics classification of ref. [84] does not apply, that new rays appear, and that 'it would be natural to extend the rigorous methods of e.g. ref. [75] ... to prove that the scalings we consider here are the only ones that lead to IR divergences.' The footnote in Sec. 2.1 similarly concedes that tropical asymptotics can miss divergent configurations at finite Schwinger parameters and asserts, without proof, that this does not happen for the diagrams treated here. Since eqs. (5.5) and (5.16) sum over the assumed rays, a missing ray with vanishing tropical function in D = 4 would contribute an additional, unexponentiated term to eq. (5.31). The explicit two-loop checks all run inside the assumed ray class and therefore do not test completeness. This is the main load-bearing gap.
  2. [Sec. 5.4 and Sec. 2.5] The exponentiation proof is carried out for ladder-type diagrams without blobs, while the abstract and eq. (1.3) present exponentiation as a property of the full QED amplitude. Section 2.5 treats diagrams beyond ladders only heuristically, stating, for example, that their IR divergences 'just effectively correct αe' and that diagram (IV) need not be included. Section 5.4 begins with 'a two-jet process without any blobs for simplicity' and asserts that the generalisation to N jets and blobs is straightforward, but no detailed proof is given that the non-ladder classes exponentiate rather than modify the hard factor. If the intended claim is only for the ladder-type class, this should be stated explicitly; otherwise the derivation needs to be extended, or a precise argument given, that all other diagram classes contribute only through coupling/mass renormalisation and wavefunction factors.
  3. [Sec. 5.5] The proof in Secs. 5.1-5.4 systematically ignores UV divergences, and only in Sec. 5.5 is an ad hoc regulator introduced. The paper claims after eq. (5.36) that H^Φ = ∫ dH^Φ is a convergent integral in four dimensions, but the argument that the regulator removes all spurious UV divergences of the subtraction terms is not given in detail; it is only stated that the UV divergences of the soft integrands are logarithmic and that Φ cuts them off. This matters because H^Φ is part of the final factorised amplitude in eq. (5.36). Either a proof of the claimed four-dimensional convergence should be supplied, or the statement should be weakened to a conjecture or a condition on the remaining hard subdiagrams.
minor comments (5)
  1. [Sec. 5.1 (after Fig. 15)] There appears to be a duplicated and partially corrupted block of text, containing an alternative notation section with symbols ϑ and ϖ and a repeated warm-up section. This block should be removed or the manuscript should be regenerated to ensure the published version does not contain it.
  2. [Eq. (2.20)] The one-loop soft integrand is defined as dS(1) with a bar in eq. (2.20), but the bar is dropped without comment in later equations such as eqs. (2.22) and (5.33). The notation should be made consistent.
  3. [Eq. (5.29)] The step from the sum over σ to the product with factors 1/(ℓ_ij!) is terse; the text should define σ explicitly as the independent permutations of photon attachments on each jet and explain that the division accounts for the overcounting of identical photon labels between each pair of jets.
  4. [Sec. 4.3] Several steps are asserted with 'one can check', notably around eqs. (4.24) and (4.47); these are straightforward matrix identities, but since the attached Mathematica notebook is meant to support reproducibility, it would be helpful to point to the specific notebook examples for these assertions.
  5. [Fig. 19] The caption and surrounding text illustrate the tiling of the positive octant for two jets at three loops; for the N-jet generalisation claimed in Sec. 5.4, the statement that the union of the domains tiles the full positive orthant deserves a more precise formulation, including the role of photons connecting different pairs of jets.

Circularity Check

0 steps flagged · score 0.0 of 10

Derivation is self-contained: exponentiation is built from the one-loop soft integrand and domain tiling, with only an explicitly stated (and non-circular) completeness assumption about tropical rays.

full rationale

The central result, S = exp( Sum over jet pairs of integral dS^(1) ) in eq. (5.31), is not assumed as an input: the one-loop soft integrand dS^(1) is independently defined in Sec. 2.1 from the divergent ray r4 of the triangle diagram, the integrand-level factorization dI ~ dI_H * prod_W dI_W is proven from the block structure of graph Laplacians in Sec. 4 (eqs. (4.60)-(4.61)), and the exponentiation in Sec. 5.4 follows by summing over photon-attachment permutations sigma and observing that the union of the worldline domains tilts the positive orthant with weight 1/ell! (eqs. (5.27)-(5.31)). This is a constructive domain argument, not a self-definitional or fitted-input prediction. The hard factor H is defined as the locally IR-finite remainder in eq. (5.17), and the paper proves that this remainder is indeed IR finite, so A = H * exp( integral dS^(1) ) is a substantive factorization statement rather than a tautology. No load-bearing self-citation is used: the tropical-geometry classification [84] is by different authors, and the paper's own citations to [72], [23], [24] are background, not the engine of the proof. The only caveat, which the paper itself flags, is the completeness of the ray class in eq. (4.1): Sec. 5.1 says 'From the tropical analysis (and by assumption), we know that soft divergences arise...', and the Conclusions state that for strictly on-shell massive amplitudes 'we are no longer in the case of generic kinematics... It would be natural to extend the rigorous methods of e.g. ref. [75] ... to prove that the scalings we consider here are the only ones that lead to IR divergences.' That is an unproven and conditional step, and a missing ray could indeed add unexponentiated terms, but it is a limitation about completeness of the assumed ray set, not a circular reduction: the ray class is not defined in terms of the exponentiation result, and no parameter is fitted to the target conclusion.

Assumptions & free parameters 0 free parameters · 6 assumptions · 0 invented entities

No free parameters are fitted to data. The central derivation rests on standard mathematics (matrix-tree theorem, tropical geometry) plus domain assumptions about which diagrams and scalings capture the IR behavior. The worldline variables beta are a change of variables, not a new entity, and the regulator Phi is a scheme choice.

assumptions (6)
  • standard math Matrix-tree theorem and Schwinger representation: U_G and F_G can be expressed via the reduced graph Laplacian L, and the Feynman integrand takes the form of eq. (1.6)/(2.47).
    Used throughout Sections 2.3 and 4 to translate factorization into matrix block-diagonalization.
  • domain assumption Newton polytope tropical rays identify the divergent scaling directions; the analysis restricts to rays with entries 0, 1, and 2.
    Sections 2.1 and 4.1. Completeness of this list for on-shell massive amplitudes is not proven; the authors call for future work in the Conclusions.
  • ad hoc to paper The soft subdiagram structure of fig. 6a: massive jet edges scale as lambda^{-1}, massless photon edges as lambda^{-2}, and hard and blob subgraphs are unscaled.
    This is the class of diagrams and scalings for which factorization is proven. It is motivated by QED ladder diagrams but not shown exhaustive.
  • domain assumption The hard-subgraph Laplacian H is invertible and O(lambda^0), and each blob Laplacian B + Gamma_B is invertible.
    Required for the block-inversion formulas in eqs. (4.22)-(4.24) and (4.47). Invertibility of reduced Laplacians holds for connected graphs, assumed for the hard and blob subgraphs.
  • domain assumption UV and IR divergences can be separated; spurious UV divergences from soft approximations are regulated by a function Phi(gamma) that leaves soft limits unchanged.
    Stated in Sections 2.1 and 5.5. The regulator is ad hoc and its physical interpretation is deferred to future work.
  • domain assumption In QED with massive electrons, diagrams beyond photon ladders either renormalize the coupling or mass or do not alter the exponentiated IR-divergent structure.
    Section 2.5 asserts this based on standard QED; it is not derived within the paper's own framework.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Soft Factorisation and Exponentiation from Schwinger-Space Geometry." pith.science (2026). https://pith.science/paper/K7AERQO7

@misc{pith2026250615603,
  author       = {Pith},
  title        = {Pith review of: Soft Factorisation and Exponentiation from Schwinger-Space Geometry},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/K7AERQO7}},
  note         = {Machine review of arXiv:2506.15603}
}
read the original abstract

Infrared divergences in Quantum Field Theory govern the low-energy dynamics of many physical theories, and their understanding is a crucial ingredient in predicting the outcomes of collider experiments. We present a novel approach to deriving the structure of these divergences by employing the Schwinger parametrization of Feynman integrals. After using tropical geometry to identify divergent limits, we study the all-orders asymptotic properties of Feynman diagrams via matrix manipulations of graph Laplacians, which allows us to analyse their IR behaviour systematically. We explicitly demonstrate the soft-hard factorization of the integrand for a broad class of diagrams, and reveal that when written in terms of "worldline distances", topologically distinct diagrams asymptote to the same integrand. In particular, for the case of Quantum Electrodynamics, we use this fact to show how ladder-type diagrams combine in Schwinger-parameter space to yield the correct exponentiated soft anomalous dimension. This framework provides a foundation for extending these methods to more complex theories like Quantum Chromodynamics and offers a pathway towards a systematic understanding of infrared divergences in perturbative amplitudes.

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

106 extracted references · 13 canonical work pages

  1. [75]

    Ma, Identifying regions in wide-angle scattering via graph-theoretical approaches , JHEP 09 (2024) 197 [ 2312.14012]

    Y. Ma, Identifying regions in wide-angle scattering via graph-theoretical approaches , JHEP 09 (2024) 197 [ 2312.14012]

  2. [84]

    Arkani-Hamed, A

    N. Arkani-Hamed, A. Hillman and S. Mizera, Feynman polytopes and the tropical geometry of UV and IR divergences , Phys. Rev. D 105 (2022) 125013 [ 2202.12296]

  3. [1]

    Agarwal, L

    N. Agarwal, L. Magnea, C. Signorile-Signorile and A. Tripathi, The infrared structure of perturbative gauge theories, Phys. Rept. 994 (2023) 1 [ 2112.07099]

  4. [2]

    Bloch and A

    F. Bloch and A. Nordsieck, Note on the Radiation Field of the electron , Phys. Rev. 52 (1937) 54

  5. [3]

    Doria, J

    R. Doria, J. Frenkel and J.C. Taylor, Counter Example to Nonabelian Bloch-Nordsieck Theorem, Nucl. Phys. B 168 (1980) 93

  6. [4]

    Di’Lieto, S

    C. Di’Lieto, S. Gendron, I.G. Halliday and C.T. Sachrajda, A Counter Example to the Bloch-Nordsieck Theorem in Nonabelian Gauge Theories , Nucl. Phys. B 183 (1981) 223

  7. [5]

    Caola, K

    F. Caola, K. Melnikov, D. Napoletano and L. Tancredi, Noncancellation of infrared singularities in collisions of massive quarks , Phys. Rev. D 103 (2021) 054013 [ 2011.04701]

  8. [6]

    Kinoshita, Mass singularities of Feynman amplitudes , J

    T. Kinoshita, Mass singularities of Feynman amplitudes , J. Math. Phys. 3 (1962) 650

Show all 106 references
  1. [7]

    Lee and M

    T.D. Lee and M. Nauenberg, Degenerate Systems and Mass Singularities , Phys. Rev. 133 (1964) B1549. – 69 –

  2. [8]

    C. Frye, H. Hannesdottir, N. Paul, M.D. Schwartz and K. Yan, Infrared Finiteness and Forward Scattering, Phys. Rev. D 99 (2019) 056015 [ 1810.10022]

  3. [9]

    Sterman and S

    G.F. Sterman and S. Weinberg, Jets from Quantum Chromodynamics , Phys. Rev. Lett. 39 (1977) 1436

  4. [10]

    Clavelli, Jet Invariant Mass in Quantum Chromodynamics , Phys

    L. Clavelli, Jet Invariant Mass in Quantum Chromodynamics , Phys. Lett. B 85 (1979) 111

  5. [11]

    Farhi, A QCD Test for Jets , Phys

    E. Farhi, A QCD Test for Jets , Phys. Rev. Lett. 39 (1977) 1587

  6. [12]

    Catani, G

    S. Catani, G. Turnock and B.R. Webber, Heavy jet mass distribution in e+ e- annihilation , Phys. Lett. B 272 (1991) 368

  7. [13]

    Catani, L

    S. Catani, L. Trentadue, G. Turnock and B.R. Webber, Resummation of large logarithms in e+ e- event shape distributions , Nucl. Phys. B 407 (1993) 3

  8. [14]

    Benitez, A.H

    M.A. Benitez, A.H. Hoang, V. Mateu, I.W. Stewart and G. Vita, On Determining αs(mZ) from Dijets in e+e− Thrust, 2412.15164

  9. [15]

    Benitez, A

    M.A. Benitez, A. Bhattacharya, A.H. Hoang, V. Mateu, M.D. Schwartz, I.W. Stewart et al., A Precise Determination of αs from the Heavy Jet Mass Distribution , 2502.12253

  10. [16]

    Larkoski, I

    A.J. Larkoski, I. Moult and B. Nachman, Jet Substructure at the Large Hadron Collider: A Review of Recent Advances in Theory and Machine Learning , Phys. Rept. 841 (2020) 1 [1709.04464]

  11. [17]

    Marzani, G

    S. Marzani, G. Soyez and M. Spannowsky, Looking inside jets: an introduction to jet substructure and boosted-object phenomenology, vol. 958, Springer (2019), 10.1007/978-3-030-15709-8, [1901.10342]

  12. [18]

    Kruczenski, J

    M. Kruczenski, J. Penedones and B.C. van Rees, Snowmass White Paper: S-matrix Bootstrap , 2203.02421

  13. [19]

    Dollard, Asymptotic Convergence and the Coulomb Interaction , Journal of Mathematical Physics 5 (1964) 729

    J.D. Dollard, Asymptotic Convergence and the Coulomb Interaction , Journal of Mathematical Physics 5 (1964) 729

  14. [20]

    Dollard, Quantum-Mechanical Scattering Theory for Short-Range and Coulomb Interactions, The Rocky Mountain Journal of Mathematics (1971) 5

    J.D. Dollard, Quantum-Mechanical Scattering Theory for Short-Range and Coulomb Interactions, The Rocky Mountain Journal of Mathematics (1971) 5

  15. [21]

    Chung, Infrared Divergence in Quantum Electrodynamics, Phys

    V. Chung, Infrared Divergence in Quantum Electrodynamics, Phys. Rev. 140 (1965) B1110

  16. [22]

    Kulish and L.D

    P.P. Kulish and L.D. Faddeev, Asymptotic Conditions and Infrared Divergences in Quantum Electrodynamics, Theor. Math. Phys. 4 (1970) 745

  17. [23]

    Hannesdottir and M.D

    H. Hannesdottir and M.D. Schwartz, Finite S matrix, Phys. Rev. D 107 (2023) L021701 [1906.03271]

  18. [24]

    Hannesdottir and M.D

    H. Hannesdottir and M.D. Schwartz, S -Matrix for massless particles , Phys. Rev. D 101 (2020) 105001 [ 1911.06821]

  19. [25]

    Becher and M

    T. Becher and M. Neubert, Infrared singularities of scattering amplitudes in perturbative QCD , Phys. Rev. Lett. 102 (2009) 162001 [ 0901.0722]

  20. [26]

    Gardi and L

    E. Gardi and L. Magnea, Infrared singularities in QCD amplitudes , Nuovo Cim. C 32N5-6 (2009) 137 [ 0908.3273]

  21. [27]

    Becher and M

    T. Becher and M. Neubert, On the Structure of Infrared Singularities of Gauge-Theory Amplitudes, JHEP 06 (2009) 081 [ 0903.1126]. – 70 –

  22. [28]

    Gardi and L

    E. Gardi and L. Magnea, Factorization constraints for soft anomalous dimensions in QCD scattering amplitudes, JHEP 03 (2009) 079 [ 0901.1091]

  23. [29]

    Collins, D.E

    J.C. Collins, D.E. Soper and G.F. Sterman, Does the Drell-Yan Cross-section Factorize? , Phys. Lett. B 109 (1982) 388

  24. [30]

    Collins, D.E

    J.C. Collins, D.E. Soper and G.F. Sterman, Factorization for One Loop Corrections in the Drell-Yan Process, Nucl. Phys. B 223 (1983) 381

  25. [31]

    Collins, D.E

    J.C. Collins, D.E. Soper and G.F. Sterman, All Order Factorization for Drell-Yan Cross-sections, Phys. Lett. B 134 (1984) 263

  26. [32]

    Sen, Asymptotic Behavior of the Wide Angle On-Shell Quark Scattering Amplitudes in Nonabelian Gauge Theories , Phys

    A. Sen, Asymptotic Behavior of the Wide Angle On-Shell Quark Scattering Amplitudes in Nonabelian Gauge Theories , Phys. Rev. D 28 (1983) 860

  27. [33]

    Collins, D.E

    J.C. Collins, D.E. Soper and G.F. Sterman, Soft Gluons and Factorization , Nucl. Phys. B 308 (1988) 833

  28. [34]

    Collins, D.E

    J.C. Collins, D.E. Soper and G.F. Sterman, Factorization of Hard Processes in QCD , Adv. Ser. Direct. High Energy Phys. 5 (1989) 1 [ hep-ph/0409313]

  29. [35]

    Contopanagos, E

    H. Contopanagos, E. Laenen and G.F. Sterman, Sudakov factorization and resummation , Nucl. Phys. B 484 (1997) 303 [ hep-ph/9604313]

  30. [36]

    Kidonakis, G

    N. Kidonakis, G. Oderda and G.F. Sterman, Evolution of color exchange in QCD hard scattering, Nucl. Phys. B 531 (1998) 365 [ hep-ph/9803241]

  31. [37]

    Aybat, L.J

    S.M. Aybat, L.J. Dixon and G.F. Sterman, The Two-loop soft anomalous dimension matrix and resummation at next-to-next-to leading pole , Phys. Rev. D 74 (2006) 074004 [hep-ph/0607309]

  32. [38]

    Feige and M.D

    I. Feige and M.D. Schwartz, An on-shell approach to factorization , Phys. Rev. D 88 (2013) 065021 [1306.6341]

  33. [39]

    Feige and M.D

    I. Feige and M.D. Schwartz, Hard-Soft-Collinear Factorization to All Orders , Phys. Rev. D 90 (2014) 105020 [ 1403.6472]

  34. [40]

    Bauer, S

    C.W. Bauer, S. Fleming and M.E. Luke, Summing Sudakov logarithms in B → Xsγin effective field theory., Phys. Rev. D 63 (2000) 014006 [ hep-ph/0005275]

  35. [41]

    Bauer, D

    C.W. Bauer, D. Pirjol and I.W. Stewart, Soft collinear factorization in effective field theory , Phys. Rev. D 65 (2002) 054022 [ hep-ph/0109045]

  36. [42]

    Beneke, A.P

    M. Beneke, A.P. Chapovsky, M. Diehl and T. Feldmann, Soft collinear effective theory and heavy to light currents beyond leading power , Nucl. Phys. B 643 (2002) 431 [hep-ph/0206152]

  37. [43]

    Stewart, Lectures on the Soft-Collinear Effective Theory , Lectures on the Soft-Collinear Effective Theory, MIT Open Courseware (2013)

    I.W. Stewart, Lectures on the Soft-Collinear Effective Theory , Lectures on the Soft-Collinear Effective Theory, MIT Open Courseware (2013)

  38. [44]

    Becher, A

    T. Becher, A. Broggio and A. Ferroglia, Introduction to Soft-Collinear Effective Theory , vol. 896, Springer (2015), 10.1007/978-3-319-14848-9, [ 1410.1892]

  39. [45]

    Polyakov, Gauge Fields as Rings of Glue , Nucl

    A.M. Polyakov, Gauge Fields as Rings of Glue , Nucl. Phys. B 164 (1980) 171

  40. [46]

    Arefeva, Quantum Contour Field Equations , Phys

    I.Y. Arefeva, Quantum Contour Field Equations , Phys. Lett. B 93 (1980) 347

  41. [47]

    Dotsenko and S.N

    V.S. Dotsenko and S.N. Vergeles, Renormalizability of Phase Factors in the Nonabelian Gauge Theory, Nucl. Phys. B 169 (1980) 527. – 71 –

  42. [48]

    Brandt, F

    R.A. Brandt, F. Neri and M.-a. Sato, Renormalization of Loop Functions for All Loops , Phys. Rev. D 24 (1981) 879

  43. [49]

    Korchemsky and A.V

    G.P. Korchemsky and A.V. Radyushkin, Loop Space Formalism and Renormalization Group for the Infrared Asymptotics of QCD , Phys. Lett. B 171 (1986) 459

  44. [50]

    Korchemsky and A.V

    G.P. Korchemsky and A.V. Radyushkin, Infrared Asymptotics of Perturbative QCD: Renormalization Properties of the Wilson Loops in Higher Orders of Perturbation Theory , Sov. J. Nucl. Phys. 44 (1986) 877

  45. [51]

    Korchemsky and A.V

    G.P. Korchemsky and A.V. Radyushkin, Renormalization of the Wilson Loops Beyond the Leading Order, Nucl. Phys. B 283 (1987) 342

  46. [52]

    Mitov, G.F

    A. Mitov, G.F. Sterman and I. Sung, The Massive Soft Anomalous Dimension Matrix at Two Loops, Phys. Rev. D 79 (2009) 094015 [ 0903.3241]

  47. [53]

    Ferroglia, M

    A. Ferroglia, M. Neubert, B.D. Pecjak and L.L. Yang, Two-loop divergences of massive scattering amplitudes in non-abelian gauge theories , JHEP 11 (2009) 062 [ 0908.3676]

  48. [54]

    Ferroglia, M

    A. Ferroglia, M. Neubert, B.D. Pecjak and L.L. Yang, Two-loop divergences of scattering amplitudes with massive partons , Phys. Rev. Lett. 103 (2009) 201601 [ 0907.4791]

  49. [55]

    Almelid, C

    O. Almelid, C. Duhr and E. Gardi, Three-loop corrections to the soft anomalous dimension in multileg scattering, Phys. Rev. Lett. 117 (2016) 172002 [ 1507.00047]

  50. [56]

    Almelid, C

    O. Almelid, C. Duhr, E. Gardi, A. McLeod and C.D. White, Bootstrapping the QCD soft anomalous dimension , JHEP 09 (2017) 073 [ 1706.10162]

  51. [57]

    Liu and N

    Z.L. Liu and N. Schalch, Infrared Singularities of Multileg QCD Amplitudes with a Massive Parton at Three Loops , Phys. Rev. Lett. 129 (2022) 232001 [ 2207.02864]

  52. [58]

    Moch, J.A.M

    S. Moch, J.A.M. Vermaseren and A. Vogt, The Three loop splitting functions in QCD: The Nonsinglet case, Nucl. Phys. B 688 (2004) 101 [ hep-ph/0403192]

  53. [59]

    A. Vogt, S. Moch and J.A.M. Vermaseren, The Three-loop splitting functions in QCD: The Singlet case, Nucl. Phys. B 691 (2004) 129 [ hep-ph/0404111]

  54. [60]

    Br¨ user, A

    R. Br¨ user, A. Grozin, J.M. Henn and M. Stahlhofen, Matter dependence of the four-loop QCD cusp anomalous dimension: from small angles to all angles , JHEP 05 (2019) 186 [1902.05076]

  55. [61]

    Henn, G.P

    J.M. Henn, G.P. Korchemsky and B. Mistlberger, The full four-loop cusp anomalous dimension in N = 4 super Yang-Mills and QCD , JHEP 04 (2020) 018 [ 1911.10174]

  56. [62]

    von Manteuffel, E

    A. von Manteuffel, E. Panzer and R.M. Schabinger, Cusp and collinear anomalous dimensions in four-loop QCD from form factors , Phys. Rev. Lett. 124 (2020) 162001 [ 2002.04617]

  57. [63]

    Ravindran, J

    V. Ravindran, J. Smith and W.L. van Neerven, Two-loop corrections to Higgs boson production, Nucl. Phys. B 704 (2005) 332 [ hep-ph/0408315]

  58. [64]

    Moch, J.A.M

    S. Moch, J.A.M. Vermaseren and A. Vogt, The Quark form-factor at higher orders , JHEP 08 (2005) 049 [ hep-ph/0507039]

  59. [65]

    S. Moch, J. Vermaseren and A. Vogt, Three-loop results for quark and gluon form-factors , Phys. Lett. B 625 (2005) 245 [ hep-ph/0508055]. – 72 –

  60. [66]

    Agarwal, A

    B. Agarwal, A. von Manteuffel, E. Panzer and R.M. Schabinger, Four-loop collinear anomalous dimensions in QCD and N=4 super Yang-Mills , Phys. Lett. B 820 (2021) 136503 [2102.09725]

  61. [67]

    Weinberg, Infrared photons and gravitons , Phys

    S. Weinberg, Infrared photons and gravitons , Phys. Rev. 140 (1965) B516

  62. [68]

    Yennie, S.C

    D.R. Yennie, S.C. Frautschi and H. Suura, The infrared divergence phenomena and high-energy processes, Annals Phys. 13 (1961) 379

  63. [69]

    X. Feal, A. Tarasov and R. Venugopalan, QED as a many-body theory of worldlines: General formalism and infrared structure , Phys. Rev. D 106 (2022) 056009 [ 2206.04188]

  64. [70]

    X. Feal, A. Tarasov and R. Venugopalan, QED as a many-body theory of worldlines. II. All-order S-matrix formalism , Phys. Rev. D 107 (2023) 096021 [ 2211.15712]

  65. [71]

    Weinzierl, Feynman Integrals

    S. Weinzierl, Feynman Integrals. A Comprehensive Treatment for Students and Researchers , UNITEXT for Physics, Springer (2022), 10.1007/978-3-030-99558-4, [ 2201.03593]

  66. [72]

    Hannesdottir and S

    H.S. Hannesdottir and S. Mizera, What is the i ε for the S-matrix? , SpringerBriefs in Physics, Springer (1, 2023), 10.1007/978-3-031-18258-7, [ 2204.02988]

  67. [73]

    Maclagan and B

    D. Maclagan and B. Sturmfels, Introduction to Tropical Geometry, Graduate Studies in Mathematics, American Mathematical Society (2015)

  68. [74]

    Gardi, F

    E. Gardi, F. Herzog, S. Jones, Y. Ma and J. Schlenk, The on-shell expansion: from Landau equations to the Newton polytope , JHEP 07 (2023) 197 [ 2211.14845]

  69. [76]

    Gardi, F

    E. Gardi, F. Herzog, S. Jones and Y. Ma, Dissecting polytopes: Landau singularities and asymptotic expansions in 2 → 2 scattering, JHEP 08 (2024) 127 [ 2407.13738]

  70. [77]

    Bjorken, Experimental tests of Quantum electrodynamics and spectral representations of Green ’s functions in perturbation theory, Ph.D

    J.D. Bjorken, Experimental tests of Quantum electrodynamics and spectral representations of Green ’s functions in perturbation theory, Ph.D. thesis, Stanford U., 1959

  71. [78]

    Landau, On analytic properties of vertex parts in quantum field theory , Nucl

    L. Landau, On analytic properties of vertex parts in quantum field theory , Nucl. Phys. 13 (1960) 181

  72. [79]

    Nakanishi, Ordinary and Anomalous Thresholds in Perturbation Theory , Prog

    N. Nakanishi, Ordinary and Anomalous Thresholds in Perturbation Theory , Prog. Theor. Phys. 22 (1959) 128

  73. [80]

    Jantzen, A.V

    B. Jantzen, A.V. Smirnov and V.A. Smirnov, Expansion by regions: revealing potential and Glauber regions automatically, Eur. Phys. J. C 72 (2012) 2139 [ 1206.0546]

  74. [81]

    Hillman, A Subtraction Scheme for Feynman Integrals , 2311.03439

    A. Hillman, A Subtraction Scheme for Feynman Integrals , 2311.03439

  75. [82]

    Salvatori, The Tropical Geometry of Subtraction Schemes , 2406.14606

    G. Salvatori, The Tropical Geometry of Subtraction Schemes , 2406.14606

  76. [83]

    Heinrich, S

    G. Heinrich, S. Jahn, S.P. Jones, M. Kerner, F. Langer, V. Magerya et al., Expansion by regions with pySecDec, Comput. Phys. Commun. 273 (2022) 108267 [ 2108.10807]

  77. [85]

    Kirchhoff, On the solution of the equations obtained from the investigation of the linear distribution of galvanic currents , IRE Transactions on Circuit Theory 5 (1958) 4

    G. Kirchhoff, On the solution of the equations obtained from the investigation of the linear distribution of galvanic currents , IRE Transactions on Circuit Theory 5 (1958) 4

  78. [86]

    Frenkel and J.C

    J. Frenkel and J.C. Taylor, Non-abelian eikonal exponentiation, Nucl. Phys. B 246 (1984) 231. – 73 –

  79. [87]

    Gardi, E

    E. Gardi, E. Laenen, G. Stavenga and C.D. White, Webs in multiparton scattering using the replica trick, JHEP 11 (2010) 155 [ 1008.0098]

  80. [88]

    Gardi, J.M

    E. Gardi, J.M. Smillie and C.D. White, On the renormalization of multiparton webs , JHEP 09 (2011) 114 [ 1108.1357]

  81. [89]

    Gardi, J.M

    E. Gardi, J.M. Smillie and C.D. White, The Non-Abelian Exponentiation theorem for multiple Wilson lines , JHEP 06 (2013) 088 [ 1304.7040]

  82. [90]

    Gawrilow and M

    E. Gawrilow and M. Joswig, polymake: a framework for analyzing convex polytopes , in Polytopes — Combinatorics and Computation , G. Kalai and G.M. Ziegler, eds., (Basel), pp. 43–73, Birkh¨ auser Basel (2000), DOI

  83. [91]

    Assarf, E

    B. Assarf, E. Gawrilow, K. Herr, M. Joswig, B. Lorenz, A. Paffenholz et al., Computing convex hulls and counting integer points with polymake , Mathematical Programming Computation 9 (2017) 1

  84. [92]

    Fevola, S

    C. Fevola, S. Mizera and S. Telen, Landau Singularities Revisited: Computational Algebraic Geometry for Feynman Integrals, Phys. Rev. Lett. 132 (2024) 101601 [ 2311.14669]

  85. [93]

    Fevola, S

    C. Fevola, S. Mizera and S. Telen, Principal Landau determinants , Comput. Phys. Commun. 303 (2024) 109278 [ 2311.16219]

  86. [94]

    Helmer, G

    M. Helmer, G. Papathanasiou and F. Tellander, Landau Singularities from Whitney Stratifications, 2402.14787

  87. [95]

    Caron-Huot, M

    S. Caron-Huot, M. Correia and M. Giroux, Recursive Landau Analysis, 2406.05241

  88. [96]

    Correia, M

    M. Correia, M. Giroux and S. Mizera, SOFIA: Singularities of Feynman Integrals Automatized, 2503.16601

  89. [97]

    Ananthanarayan, A

    B. Ananthanarayan, A. Pal, S. Ramanan and R. Sarkar, Unveiling Regions in multi-scale Feynman Integrals using Singularities and Power Geometry , Eur. Phys. J. C 79 (2019) 57 [1810.06270]

  90. [98]

    Arkani-Hamed, C

    N. Arkani-Hamed, C. Figueiredo and F. Vaz˜ ao,Cosmohedra, 2412.19881

  91. [99]

    Anastasiou and G

    C. Anastasiou and G. Sterman, Removing infrared divergences from two-loop integrals, JHEP 07 (2019) 056 [ 1812.03753]

  92. [100]

    Anastasiou, R

    C. Anastasiou, R. Haindl, G. Sterman, Z. Yang and M. Zeng, Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation , JHEP 04 (2021) 222 [ 2008.12293]

  93. [101]

    Anastasiou and G

    C. Anastasiou and G. Sterman, Locally finite two-loop QCD amplitudes from IR universality for electroweak production, JHEP 05 (2023) 242 [ 2212.12162]

  94. [102]

    Anastasiou, J

    C. Anastasiou, J. Karlen, G. Sterman and A. Venkata, Locally finite two-loop amplitudes for electroweak production through gluon fusion , JHEP 11 (2024) 043 [ 2403.13712]

  95. [103]

    Kermanschah and M

    D. Kermanschah and M. Vicini, Nf -contribution to the virtual correction for electroweak vector boson production at NNLO , 2407.18051

  96. [104]

    Arkani-Hamed, H

    N. Arkani-Hamed, H. Frost, G. Salvatori, P.-G. Plamondon and H. Thomas, All Loop Scattering As A Counting Problem , 2309.15913. – 74 –

  97. [105]

    Arkani-Hamed, H

    N. Arkani-Hamed, H. Frost, G. Salvatori, P.-G. Plamondon and H. Thomas, All Loop Scattering For All Multiplicity , 2311.09284

  98. [106]

    Weinberg, The Quantum theory of fields

    S. Weinberg, The Quantum theory of fields. Vol. 1: Foundations , Cambridge University Press (6, 2005), 10.1017/CBO9781139644167. – 75 –

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.