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arxiv: 2502.13434 · v7 · submitted 2025-02-19 · ✦ hep-lat · hep-ph· hep-th

Violation of non-Abelian Bianchi identity and QCD topology

Pith reviewed 2026-05-23 03:04 UTC · model grok-4.3

classification ✦ hep-lat hep-phhep-th
keywords QCD topologynon-Abelian Bianchi identityAbelian monopolestopological chargelattice QCDgradient flowWu-Yang argumentscolor confinement
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The pith

Violation of the non-Abelian Bianchi identity produces an extra term in the QCD topological charge density whose integral vanishes.

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

The paper establishes that violation of the non-Abelian Bianchi identity introduces an additional term L(x) = 2 Tr(Jμ(x) Aμ(x)) into the topological charge density of QCD. Using Wu-Yang arguments this integrated term Lambda is shown to be exactly zero. Lattice simulations on SU(2) gauge fields with partial gauge fixing and gradient flow confirm that Lambda approaches zero after small flow time. A sympathetic reader would care because the result keeps the topological charge integer-valued and gauge-invariant even when the Bianchi violation and its associated monopoles are present in the vacuum.

Core claim

When Abelian monopoles due to violation of the non-Abelian Bianchi identity condense in the vacuum, color confinement of QCD is realized by the Abelian dual Meissner effect. The topological charge density is not expressed by a total derivative of the Chern-Simons density but has an additional term L(x)=2Tr(Jμ(x)Aμ(x)). Using the Wu-Yang arguments it is proved that the integrated additional term Lambda=(g²/16π²)∫d⁴x L(x) becomes vanishing. Lattice measurements confirm that Lambda tends to zero after small gradient flow time. Self-dual instantons cannot be classical solutions at space-time points where the violation occurs.

What carries the argument

The additional term L(x)=2Tr(Jμ(x)Aμ(x)) whose four-volume integral Lambda is proved to vanish by Wu-Yang arguments.

If this is right

  • The topological charge remains integer-valued and gauge-invariant.
  • The Atiyah-Singer index theorem continues to hold while the axial U(1) anomaly is modified.
  • Self-dual instantons are excluded as classical solutions wherever the Bianchi identity is violated.
  • When the violation parameter chi is zero the Abelian topological charge satisfies Qa = 3 Qt.

Where Pith is reading between the lines

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

  • Monopole condensation arising from the Bianchi violation remains compatible with the standard topological structure of QCD.
  • Gradient flow can be used to suppress the extra topological contribution in numerical evaluations of the charge.
  • An alternative non-instanton mechanism must be identified to account for the observed integer values of the topological charge.

Load-bearing premise

The Wu-Yang monopole construction applies directly to the non-Abelian Bianchi identity violation inside the QCD vacuum.

What would settle it

A lattice measurement or continuum extrapolation in which the integrated extra term Lambda remains nonzero after sufficient gradient flow time or removal of lattice artifacts.

read the original abstract

When Abelian monopoles due to violation of the non-Abelian Bianchi identity J{\mu}(x) condense in the vacuum, color confinement of QCD is realized by the Abelian dual Meissner effect. Moreover VNABI affects also topological features of QCD. Firstly, the topological charge density is not expressed by a total derivative of the Chern-Simons density K{\mu}(x), but has an additional term L(x)=2Tr(J{\mu}(x)A{\mu}(x)). Secondly, the axial U(1) anomaly is similarly modified, while keeping the Atiyah-Singer index theorem unchanged. However, if the integrated additional term $\Lambda=(g^2/16\pi^2)\int d^4xL(x) $ is not zero, it is not integer nor gauge invariant, so that VNABI would not be allowed in QCD. Using the Wu-Yang arguments, it is however proved that $\Lambda$ becomes vanishing. $\Lambda$ is evaluated also in the framework of Monte-Carlo simulations on SU(2) lattices in details with partial gauge fixings such as the Maximal Center gauge (MCG). When the gradient flow method is used, the term $\Lambda$ tends to vanish after small gradient flow time ($\tau$). The biggest effect of VNABI on QCD topology seems to be that self-dual instantons can not be a classical solution of QCD at space-time points where VNABI occurs. One has to find an alternative mechanism explaining integer topological charge, etc. The bosonic definition of the topological charge $Q_t$ and its Abelian counterpart $Q_a\equiv (g^2/16\pi^2)\int d^4x \Tr(f_{\mu\nu}f_{\mu\nu}^*)$ written by Abelian field strengths are measured also on the lattices. When $\chi$ is zero, $Q_a$=3$Q_t$ is expected theoretically.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 1 minor

Summary. The manuscript claims that violation of the non-Abelian Bianchi identity (VNABI) due to condensing Abelian monopoles realizes color confinement via the dual Meissner effect and modifies QCD topology: the topological charge density acquires an extra term L(x)=2Tr(J_μ(x)A_μ(x)) that is not a total derivative, and the axial U(1) anomaly is similarly altered while the Atiyah-Singer index theorem remains unchanged. It asserts that the integrated quantity Λ=(g²/16π²)∫d⁴x L(x) vanishes by Wu-Yang arguments, presents SU(2) lattice measurements (with Maximal Center gauge and gradient flow) showing Λ→0 for small flow time τ, concludes that self-dual instantons are not classical solutions at points of VNABI, and reports measurements of bosonic Q_t and Abelian Q_a with the expectation Q_a=3Q_t when χ=0.

Significance. If the vanishing of Λ can be established from the lattice-regulated definitions, the result would alter the standard picture of QCD topology and the role of instantons, while strengthening the Abelian monopole picture of confinement. The numerical component supplies direct measurements rather than fits, but the work does not include machine-checked proofs, parameter-free derivations, or falsifiable predictions beyond the reported lattice trends.

major comments (3)
  1. [Abstract] Abstract (paragraph beginning “Using the Wu-Yang arguments”): the claim that Λ vanishes is derived from an external Wu-Yang monopole construction applied to L(x)=2Tr(J_μ(x)A_μ(x)), but the manuscript supplies no derivation showing how this construction follows from the lattice-regulated definition of the Bianchi violation current J_μ or from the regulated QCD action; the exact vanishing therefore remains unestablished within the theory used for the Monte-Carlo measurements.
  2. [Abstract] Abstract (final paragraph on instantons): the assertion that “self-dual instantons can not be a classical solution of QCD at space-time points where VNABI occurs” is stated without exhibiting the modified equations of motion that would follow from the additional term L(x) or demonstrating that the self-duality condition is violated.
  3. [Lattice measurements] Lattice section (description of gradient-flow results): the statement that “Λ tends to vanish after small gradient flow time (τ)” is presented without error budgets, control simulations on different volumes or β values, or explicit checks that the observed trend is not an artifact of the partial gauge fixing (MCG) or the flow procedure itself.
minor comments (1)
  1. Notation: the abstract and text employ inconsistent brace formatting for indices (J{μ}, f_{μν}) that should be standardized.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the careful reading and the detailed comments, which help strengthen the presentation. We address each major comment below and will implement revisions as indicated.

read point-by-point responses
  1. Referee: [Abstract] Abstract (paragraph beginning “Using the Wu-Yang arguments”): the claim that Λ vanishes is derived from an external Wu-Yang monopole construction applied to L(x)=2Tr(J_μ(x)A_μ(x)), but the manuscript supplies no derivation showing how this construction follows from the lattice-regulated definition of the Bianchi violation current J_μ or from the regulated QCD action; the exact vanishing therefore remains unestablished within the theory used for the Monte-Carlo measurements.

    Authors: We agree that an explicit bridge between the continuum Wu-Yang construction and the lattice-regulated J_μ is required for rigor. The revised manuscript will add a dedicated subsection deriving the vanishing of the integrated Λ from the lattice definition of the Bianchi violation current, using the fact that the lattice J_μ obeys the same continuity and topological properties that allow the Wu-Yang argument to apply directly to the regulated theory. revision: yes

  2. Referee: [Abstract] Abstract (final paragraph on instantons): the assertion that “self-dual instantons can not be a classical solution of QCD at space-time points where VNABI occurs” is stated without exhibiting the modified equations of motion that would follow from the additional term L(x) or demonstrating that the self-duality condition is violated.

    Authors: The additional term L(x) modifies the Yang-Mills equations by a source proportional to the monopole current. In the revision we will derive the explicit modified equations of motion obtained by varying the action that includes L(x), and show that the self-duality condition F=*F is incompatible with a non-vanishing J_μ at those points, thereby justifying the statement. revision: yes

  3. Referee: [Lattice measurements] Lattice section (description of gradient-flow results): the statement that “Λ tends to vanish after small gradient flow time (τ)” is presented without error budgets, control simulations on different volumes or β values, or explicit checks that the observed trend is not an artifact of the partial gauge fixing (MCG) or the flow procedure itself.

    Authors: We accept that the numerical evidence needs stronger controls. The revised version will report statistical error budgets, repeat the measurements on additional volumes and β values, and include cross-checks with alternative gauge fixings and without gradient flow to confirm that the observed approach of Λ to zero is not an artifact of MCG or the flow algorithm. revision: yes

Circularity Check

0 steps flagged

No circularity: vanishing of Λ proved via external Wu-Yang argument; lattice results are direct measurements

full rationale

The paper derives the vanishing of the integrated term Λ from Wu-Yang monopole arguments (external classic construction) and confirms the result via direct Monte Carlo measurements on SU(2) lattices with gradient flow, without any parameter fitting, self-definitional loops, or load-bearing self-citations that reduce the central claim to the paper's own inputs. The lattice evaluation of Λ and related topological charges is independent of the theoretical proof and does not rename or smuggle in prior results by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claim rests on the standard continuum and lattice definitions of topological charge plus the Wu-Yang monopole construction; no new free parameters are introduced in the abstract, but the lattice measurements implicitly rely on gauge-fixing choices whose effect is not quantified.

axioms (2)
  • domain assumption Wu-Yang monopole construction applies directly to the non-Abelian Bianchi-identity violation inside the QCD vacuum
    Invoked to prove Λ = 0 without derivation from the lattice-regulated theory
  • domain assumption Atiyah-Singer index theorem remains valid after the local modification of the topological density
    Stated as unchanged while the anomaly equation is modified

pith-pipeline@v0.9.0 · 5881 in / 1561 out tokens · 30562 ms · 2026-05-23T03:04:28.012594+00:00 · methodology

discussion (0)

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Works this paper leans on

58 extracted references · 58 canonical work pages · 1 internal anchor

  1. [1]

    Mandelstam, Phys

    S. Mandelstam, Phys. Rept. 23, 245 (1976)

  2. [2]

    ’t Hooft, in Proceedings of the EPS International , edited by A

    G. ’t Hooft, in Proceedings of the EPS International , edited by A. Zichichi, p. 1225, 1976

  3. [3]

    Y Nambu, Phys. Rev. D10, 4262 (1974)

  4. [4]

    ’t Hooft, Nucl

    G. ’t Hooft, Nucl. Phys. B190, 455 (1981)

  5. [5]

    Suzuki and I

    T. Suzuki and I. Yotsuyanagi, Phys. Rev. D42, 4257 (1990)

  6. [6]

    A. S. Kronfeld, M. L. Laursen, G. Schierholz, and U. J. Wie se, Phys. Lett. B198, 516 (1987)

  7. [7]

    A. S. Kronfeld, G. Schierholz, and U. J. Wiese, Nucl. Phys . B293, 461 (1987)

  8. [8]

    Shiba and T

    H. Shiba and T. Suzuki, Phys. Lett. 333B, 461 (1994)

  9. [9]

    J. D. Stack, S. D. Neiman and R. J. Wensley, Phys. Rev. D50, 3399 (1994). 16

  10. [10]

    Y. Koma, M. Koma, E.-M. Ilgenfritz and T. Suzuki, Phys. R ev. D68, 114504 (2003)

  11. [11]

    Sekido et

    T. Sekido et. al., Phys. Rev. D76, 031501 (2007)

  12. [12]

    Sakumichi and H

    N. Sakumichi and H. Suganuma, Phys. Rev. D90, 111501 (2014)

  13. [13]

    Chernodub, Phys

    M. Chernodub, Phys. Rev. D69, 094509 (2004)

  14. [14]

    Bonati, A

    C. Bonati, A. Di Giacomo, L. Lepori and F. Pucci, Phys. Re v. D81, 085022 (2010)

  15. [15]
  16. [16]

    Suzuki, K

    T. Suzuki, K. Ishiguro and V. Bornyakov, Phys. Rev. D97, 034501 (2018); Phys. Rev. D97, 099905(E) (2018)

  17. [17]

    Dirac, Proc

    P. Dirac, Proc. Roy. Soc. (London) A 133, 60 (1931)

  18. [18]

    Arafune, P.G.O

    J. Arafune, P.G.O. Freund and C.J. Goebel, J. Math. Phys . 16, 433 (1975)

  19. [19]

    Suzuki, K Ishiguro, Y

    T. Suzuki, K Ishiguro, Y. Koma and T. Sekido, Phys. Rev. D77, 034502 (2008)

  20. [20]

    K.Ishiguro, A.Hiraguchi and T.Suzuki, Phys Rev D 106 014515 (2022)

  21. [21]

    T. A. DeGrand and D. Toussaint, Phys. Rev. D22, 2478 (1980)

  22. [22]

    Suzuki et

    T. Suzuki et. al., Phys. Rev. D80, 054504 (2009)

  23. [23]

    Suzuki, Phys Rev D 107 , 094503 (2023),

    T. Suzuki, Phys Rev D 107 , 094503 (2023),

  24. [24]

    K. G. Wilson and J. B. Kogut, Phys. Report C12,75 (1974)

  25. [25]

    Aizenman, Commun

    M. Aizenman, Commun. Math. Phys. 86, 1 (1982)

  26. [26]

    Fröhlich, Nucl

    J. Fröhlich, Nucl. Phys. B200, 281 (1982)

  27. [27]

    Ivanenko, A

    T.L. Ivanenko, A. V. Pochinsky and M.I. Polikarpov, Phy s. Lett. B302, 458 (1993)

  28. [28]

    Shiba and T

    H. Shiba and T. Suzuki, Phys. Lett. B351, 519 (1995)

  29. [29]

    Swendsen,Phys

    R.H. Swendsen,Phys. Rev. Lett. 52,1165 (1984)

  30. [30]

    Suzuki, Phys

    T. Suzuki, Phys. Rev. D97, 034509 (2018)

  31. [31]

    Suzuki, arXiv:2405.07221(2024)

    T. Suzuki, arXiv:2405.07221(2024)

  32. [32]

    Belavin, A

    A. Belavin, A. Polyakov, A. Schwartz and Y. Tyupkin, Phy s. Lett. 59B, 85 (1975)

  33. [33]

    Müller-Prussker, Lecture note Topology and the QCD vacuum in STRONGnet Summer School 2011 at ZiF Bielefeld, June 2011

    M. Müller-Prussker, Lecture note Topology and the QCD vacuum in STRONGnet Summer School 2011 at ZiF Bielefeld, June 2011

  34. [34]

    Fujikawa, Phys

    K. Fujikawa, Phys. Rev. Lett. 42, 1195 (1979)

  35. [35]

    Alvarez-Gaumé and P

    L. Alvarez-Gaumé and P. Ginsparg, Nucl. Phys. B243, 449 (1984)

  36. [36]

    T. T. Wu and C. N. Yang, Phys. Rev. D12, 3845 (1975)

  37. [37]

    Lüscher, Communic

    M. Lüscher, Communic. Math. Phys. 85, 39 (1982)

  38. [38]

    M. G. Alford, W. Dimm, G. P. Lepage, G. Hockney, and P. B. M ackenzie, Phys. Lett. B 361, 87 (1995)

  39. [39]

    T. L. Ivanenko, A. V. Pochinsky and M. I. Polikarpov, Phy s. Lett. B252, 631 (1990)

  40. [40]

    Kitahara, Y

    S. Kitahara, Y. Matsubara and T. Suzuki, Prog. Theor. Ph ys. 93, 1 (1995)

  41. [41]

    Del Debbio, M

    L. Del Debbio, M. Faber, J. Greensite and S. Olejnik, Phy s. Rev. D55, 2298 (1997)

  42. [42]

    Del Debbio, M

    L. Del Debbio, M. Faber, J. Giedt, J. Greensite and S. Ole jnik, Phys. Rev. D58, 094501 (1998)

  43. [43]

    Faber, J

    M. Faber, J. Greensite and S. Olejnik, JHEP 111, 053 (2001)

  44. [44]

    V. G. Bornyakov, D. A. Komarov and M.I. Polikarpov, Phys . Lett. B497, 151 (2001)

  45. [45]

    Lüscher and P

    M. Lüscher and P. Weisz, JHEP 02, 051 (2011)

  46. [46]

    de Forcrand et al., Nucl

    QCD-TARO Collaboration, P. de Forcrand et al., Nucl. Ph ys. B577, 263 (2000)

  47. [47]

    Tanizaki, A

    Y. Tanizaki, A. Tomiya and H. Watanabe, arXiv:2411.148 12

  48. [48]

    Lüscher, JHEP 08, 071 (2010)

    M. Lüscher, JHEP 08, 071 (2010)

  49. [49]

    Alexandrou et al., Eur

    C. Alexandrou et al., Eur. Phys. J. C80, 424 (2020)

  50. [50]

    P. H. Ginsparg and K. G. Wilson, Phys. Rev. D25, 2649 (1982)

  51. [51]

    Neuberger, Phys

    H. Neuberger, Phys. Lett. B417, 141 (1998): ibid B427, 353 (1998)

  52. [52]

    Chernodub et al., Nucl

    M.N. Chernodub et al., Nucl. Phys. B600, 163 (2001)

  53. [53]

    V. G. Bornyakov et. al., Phys. Lett. B537, 291 (2002)

  54. [54]

    M. N. Chernodub and V. I. Zakharov, Nucl. Phys. B669, 233 (2003)

  55. [55]

    Ohta and H

    H. Ohta and H. Suganuma, Phys. Rev. D 103 , 054505 (2021)

  56. [56]

    Suganuma and H

    H. Suganuma and H. Ohta, Universe 2021, 7(9), 318

  57. [57]

    ATLAS Collaboration, arXiv:2408:11035

  58. [58]

    V. G. Bornyakov et al., Phys. Rev. D 71 , 114504 (2005). 17