Recognition: no theorem link
Non-Abelian and Type-A Conformal Anomalies from Euler Descent
Pith reviewed 2026-05-16 10:29 UTC · model grok-4.3
The pith
Non-Abelian anomalies of the Euclidean conformal group descend from the Euler polynomial in two dimensions higher.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The authors classify the non-Abelian anomaly of the Euclidean conformal group SO(2n+1,1) in 2n dimensions via Stora-Zumino descent from its Euler invariant polynomial in 2n+2 dimensions. This places the conformal anomaly on the same footing as ordinary perturbative 't Hooft anomalies. They also explore the relation of the non-Abelian anomaly to the known type-A Weyl anomaly, which involves projecting into a Weyl cocycle, and discuss implications for anomaly inflow and 't Hooft anomaly matching for the full conformal group with a Wess-Zumino-Witten term. In 4d, this enables the construction of a dilaton effective action matching the full non-Abelian SO(5,1) conformal anomaly.
What carries the argument
Stora-Zumino descent applied to the Euler invariant polynomial, generating the anomaly cocycle for the full non-Abelian conformal group.
If this is right
- The conformal anomaly can be matched under 't Hooft anomaly matching conditions using a Wess-Zumino-Witten term for the full conformal group.
- Anomaly inflow from a higher-dimensional topological term reproduces the non-Abelian conformal anomaly.
- In four dimensions the descended cocycle supplies an explicit dilaton effective action that matches the complete SO(5,1) anomaly.
- The non-Abelian anomaly is related to the type-A Weyl anomaly by projection onto the appropriate Weyl cocycle.
Where Pith is reading between the lines
- The same descent procedure could be used to construct consistent effective actions when conformal symmetry is spontaneously broken in higher even dimensions.
- It suggests that anomaly inflow provides a geometric origin for conformal anomalies that may appear in holographic duals without additional assumptions.
- Explicit matching of the full non-Abelian anomaly may constrain possible ultraviolet completions that preserve the entire conformal group.
- The method offers a route to compute anomaly coefficients in dimensions beyond four without relying on perturbative expansions.
- keywords:[
- conformal anomaly
- non-Abelian anomaly
- Stora-Zumino descent
Load-bearing premise
The Euler polynomial in 2n+2 dimensions descends to a non-trivial cocycle for the full non-Abelian conformal group without additional obstructions or vanishing conditions specific to the conformal case.
What would settle it
A direct calculation of the conformal anomaly in four dimensions that yields coefficients different from those obtained by descending the six-dimensional Euler polynomial and projecting to the Weyl cocycle.
read the original abstract
We classify the non-Abelian anomaly of the Euclidean conformal group $SO(2n+1,1)$ in $2n$ dimensions via Stora-Zumino descent from its Euler invariant polynomial in $2n+2$ dimensions. In this way, we place the conformal anomaly on the same footing as ordinary perturbative 't Hooft anomalies. We also explore the relation of the non-Abelian anomaly to the known \textit{type-A Weyl anomaly}, which involves projecting into a Weyl cocycle. We discuss implications for anomaly inflow, and 't Hooft anomaly matching for the full conformal group with a Wess-Zumino-Witten term. In 4d, this enables the construction of a dilaton effective action matching the full non-Abelian $SO(5,1)$ conformal anomaly.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript claims to classify the non-Abelian anomaly of the Euclidean conformal group SO(2n+1,1) in 2n dimensions by applying Stora-Zumino descent to the Euler invariant polynomial in 2n+2 dimensions. This places the conformal anomaly on equal footing with ordinary 't Hooft anomalies. The work further relates the resulting cocycle to the type-A Weyl anomaly via projection onto a Weyl factor, discusses implications for anomaly inflow and 't Hooft matching with a WZW term, and constructs a dilaton effective action in 4d that matches the full non-Abelian SO(5,1) anomaly.
Significance. If the descent produces a non-trivial cocycle for the full non-Abelian group, the result would provide a systematic, descent-based classification of conformal anomalies analogous to gauge anomalies, enabling consistent anomaly matching and effective actions. The explicit 4d dilaton construction offers a concrete, testable application for conformal field theory studies.
major comments (1)
- [Stora-Zumino descent and projection onto Weyl cocycle] The central claim that Stora-Zumino descent from the Euler polynomial yields a non-vanishing (2n-1)-cocycle for the full non-Abelian SO(2n+1,1) action rests on the assumption of no conformal-specific obstructions. The abstract notes that the type-A anomaly arises only after projecting the cocycle onto a Weyl factor; this projection step indicates that unprojected components may vanish due to non-compactness, the metric representation, or Euclidean signature. Explicit cocycle expressions or a verification that the descent remains non-trivial without projection are required to support the classification.
minor comments (1)
- [Abstract] The abstract refers to results 'in 4d' without stating the range of n for which the general classification holds; adding this clarification would improve readability.
Simulated Author's Rebuttal
We thank the referee for their careful reading of the manuscript and for identifying the need to strengthen the evidence for the non-vanishing of the full non-Abelian cocycle. We address the major comment below and will incorporate clarifications and explicit expressions in a revised version.
read point-by-point responses
-
Referee: The central claim that Stora-Zumino descent from the Euler polynomial yields a non-vanishing (2n-1)-cocycle for the full non-Abelian SO(2n+1,1) action rests on the assumption of no conformal-specific obstructions. The abstract notes that the type-A anomaly arises only after projecting the cocycle onto a Weyl factor; this projection step indicates that unprojected components may vanish due to non-compactness, the metric representation, or Euclidean signature. Explicit cocycle expressions or a verification that the descent remains non-trivial without projection are required to support the classification.
Authors: The Stora-Zumino descent is performed on the Euler invariant polynomial in the standard manner, yielding a non-trivial (2n-1)-cocycle for the full conformal group action; the non-vanishing follows directly from the topological properties of the Euler class and the absence of additional obstructions in the descent equations for this case. The projection onto a Weyl factor is introduced only to isolate the type-A component and relate it to the known Weyl anomaly, but the unprojected cocycle remains non-zero for general conformal transformations. To address the request for explicit verification, we will include the explicit form of the (2n-1)-cocycle in the revised manuscript together with a direct check that it satisfies the descent equations without vanishing prior to projection. revision: yes
Circularity Check
Standard Stora-Zumino descent from independently known Euler polynomial; derivation self-contained
full rationale
The paper's central construction starts from the known Euler invariant polynomial in 2n+2 dimensions and applies the standard Stora-Zumino descent procedure to obtain the non-Abelian anomaly cocycle for SO(2n+1,1). No equations or steps in the provided abstract or description reduce the result to a self-definition, a fitted parameter renamed as prediction, or a load-bearing self-citation chain. The type-A projection is presented as an additional step after descent, not as a redefinition of the input. The derivation is therefore independent of its own outputs and receives the default non-circularity finding.
Axiom & Free-Parameter Ledger
axioms (2)
- standard math The Euler polynomial in 2n+2 dimensions is a closed invariant that descends to a non-trivial cocycle for the conformal group in 2n dimensions.
- domain assumption Projection onto the Weyl cocycle recovers the known type-A anomaly without loss of information about the non-Abelian structure.
Reference graph
Works this paper leans on
-
[1]
J. Wess and B. Zumino,Consequences of anomalous ward identities,Physics Letters B37 (1971) 95–97
work page 1971
-
[2]
B. Zumino,Chiral anomalies and differential geometry: Lectures given at Les Houches, August 1983, inLes Houches Summer School on Theoretical Physics: Relativity, Groups and Topology, pp. 1291–1322, 10, 1983
work page 1983
-
[3]
Stora,Algebraic structure and topological origin of anomalies,NATO Sci.Ser.B115 (1984)
R. Stora,Algebraic structure and topological origin of anomalies,NATO Sci.Ser.B115 (1984)
work page 1984
- [4]
-
[5]
C. G. Callan, Jr. and J. A. Harvey,Anomalies and Fermion Zero Modes on Strings and Domain Walls,Nucl. Phys. B250(1985) 427–436
work page 1985
-
[6]
Symmetry Protected Topological Phases, Anomalies, and Cobordisms: Beyond Group Cohomology
A. Kapustin,Symmetry protected topological phases, anomalies, and cobordisms,arXiv preprint(2014) , [1403.1467]
work page internal anchor Pith review Pith/arXiv arXiv 2014
-
[7]
Fermion Path Integrals And Topological Phases
E. Witten,Fermion path integrals and topological phases,Reviews of Modern Physics88 (2016) 035001, [1508.04715]
work page internal anchor Pith review Pith/arXiv arXiv 2016
-
[8]
S. S. Chern and J. Simons,Characteristic forms and geometric invariants,Annals Math.99 (1974) 48–69
work page 1974
- [9]
-
[10]
E. Witten,Quantum field theory and the jones polynomial,Communications in Mathematical Physics121(1989) 351–399
work page 1989
-
[11]
R. Dijkgraaf and E. Witten,Topological gauge theories and group cohomology, Communications in Mathematical Physics129(1990) 393–429
work page 1990
-
[12]
C. Csaki and H. Murayama,Discrete anomaly matching,Nucl. Phys. B515(1998) 114–162, [hep-th/9710105]
work page internal anchor Pith review Pith/arXiv arXiv 1998
-
[13]
Anomalies of discrete symmetries in three dimensions and group cohomology
A. Kapustin and R. Thorngren,Anomalies of discrete symmetries in three dimensions and group cohomology,Physical Review Letters112(2014) 231602, [1403.0617]
work page internal anchor Pith review Pith/arXiv arXiv 2014
-
[14]
Coupling a QFT to a TQFT and Duality
A. Kapustin and N. Seiberg,Coupling a qft to a tqft and duality,Journal of High Energy Physics2014(2014) 001, [1401.0740]
work page internal anchor Pith review Pith/arXiv arXiv 2014
-
[15]
Graphene Quantum Strain Transistors
P.-S. Hsin and H. T. Lam,Anomaly in finite group symmetry: Obstruction to symmetry extension,Physical Review B100(2019) 075105, [1809.09679]
work page internal anchor Pith review Pith/arXiv arXiv 2019
-
[16]
D. Gaiotto, A. Kapustin, N. Seiberg and B. Willett,Generalized global symmetries,Journal of High Energy Physics2015(2015) 172, [1412.5148]
work page internal anchor Pith review Pith/arXiv arXiv 2015
-
[17]
Gauging spatial symmetries and the classification of topological crystalline phases
R. Thorngren and D. V. Else,Gauging spatial symmetries and the classification of topological crystalline phases,Physical Review X8(2018) 011040, [1612.00846]
work page internal anchor Pith review Pith/arXiv arXiv 2018
- [18]
-
[19]
From Dynkin diagram symmetries to fixed point structures
J. Fuchs, A. N. Schellekens and C. Schweigert,From dynkin diagram symmetries to fixed point structures,Communications in Mathematical Physics180(1996) 39–97, [hep-th/9506135]. – 16 –
work page internal anchor Pith review Pith/arXiv arXiv 1996
-
[20]
F. A. Bais and J. K. Slingerland,Condensate-induced transitions between topologically ordered phases,Physical Review B79(2009) 045316, [0808.0627]
work page internal anchor Pith review Pith/arXiv arXiv 2009
- [21]
-
[22]
Tidal effects away from the equatorial plane in Kerr backgrounds
C. Cordova and K. Ohmori,Anomaly constraints on non-invertible symmetries in quantum field theory,Physical Review D100(2019) 125003, [1812.08642]
work page internal anchor Pith review Pith/arXiv arXiv 2019
-
[23]
F. Benini and Y. Tachikawa,Non-invertible symmetries and the bootstrap,SciPost Physics 13(2022) 063, [2112.12165]
-
[24]
M. J. Duff,Observations on Conformal Anomalies,Nucl. Phys. B125(1977) 334–348
work page 1977
- [25]
- [26]
-
[27]
M. J. Duff,Twenty years of the Weyl anomaly,Class. Quant. Grav.11(1994) 1387–1404, [hep-th/9308075]
work page internal anchor Pith review Pith/arXiv arXiv 1994
-
[28]
Geometric Classification of Conformal Anomalies in Arbitrary Dimensions
S. Deser and A. Schwimmer,Geometric classification of conformal anomalies in arbitrary dimensions,Phys. Lett. B309(1993) 279–284, [hep-th/9302047]
work page internal anchor Pith review Pith/arXiv arXiv 1993
-
[29]
Spontaneous Breaking of Conformal Invariance and Trace Anomaly Matching
A. Schwimmer and S. Theisen,Spontaneous Breaking of Conformal Invariance and Trace Anomaly Matching,Nucl. Phys. B847(2011) 590–611, [1011.0696]
work page internal anchor Pith review Pith/arXiv arXiv 2011
-
[30]
A. B. Zamolodchikov,Irreversibility of the Flux of the Renormalization Group in a 2D Field Theory,JETP Lett.43(1986) 730–732
work page 1986
-
[31]
J. L. Cardy,Is there a c-theorem in four dimensions?,Phys. Lett. B215(1988) 749–752
work page 1988
-
[32]
On Renormalization Group Flows in Four Dimensions
Z. Komargodski and A. Schwimmer,On Renormalization Group Flows in Four Dimensions, JHEP12(2011) 099, [1107.3987]
work page internal anchor Pith review Pith/arXiv arXiv 2011
-
[33]
The Constraints of Conformal Symmetry on RG Flows
Z. Komargodski,The Constraints of Conformal Symmetry on RG Flows,JHEP07(2012) 069, [1112.4538]
work page internal anchor Pith review Pith/arXiv arXiv 2012
-
[34]
On the RG running of the entanglement entropy of a circle
H. Casini, M. Huerta and R. C. Myers,Towards a derivation of holographic entanglement entropy,JHEP05(2012) 036, [1202.5650]
work page internal anchor Pith review Pith/arXiv arXiv 2012
-
[35]
Algebraic Classification of Weyl Anomalies in Arbitrary Dimensions
N. Boulanger,Algebraic Classification of Weyl Anomalies in Arbitrary Dimensions,Phys. Rev. Lett.98(2007) 261302, [0706.0340]
work page internal anchor Pith review Pith/arXiv arXiv 2007
-
[36]
Rovere,Anomalies in covariant fracton theories,Phys
D. Rovere,Anomalies in covariant fracton theories,Phys. Rev. D110(2024) 085012, [2406.06686]
-
[37]
D. R. Karakhanian, R. P. Manvelyan and R. L. Mkrtchian,Trace anomalies and cocycles of Weyl and diffeomorphism groups,Mod. Phys. Lett. A11(1996) 409–422, [hep-th/9411068]
work page internal anchor Pith review Pith/arXiv arXiv 1996
-
[38]
F. Apruzzi, N. Dondi, I. Garc´ ıa Etxebarria, H. T. Lam and S. Schafer-Nameki,Symmetry TFTs for Continuous Spacetime Symmetries,2509.07965
- [39]
-
[40]
L. Bhardwaj, C. Copetti, D. Pajer and S. Schafer-Nameki,Boundary SymTFT,SciPost Phys.19(2025) 061, [2409.02166]. – 17 –
-
[41]
F. Bonetti, M. Del Zotto and R. Minasian,SymTFTs for continuous non-Abelian symmetries,Phys. Lett. B871(2025) 140010, [2402.12347]
-
[42]
Spontaneous Breaking of Space-Time Symmetries
E. Rabinovici,Spontaneous Breaking of Space-Time Symmetries,Lect. Notes Phys.737 (2008) 573–605, [0708.1952]
work page internal anchor Pith review Pith/arXiv arXiv 2008
-
[43]
C. Imbimbo, D. Rovere and A. Warman,Superconformal anomalies from superconformal Chern-Simons polynomials,JHEP05(2024) 277, [2311.05684]
-
[44]
C. Imbimbo and L. Porro,One Ring to Rule Them All: A Unified Topological Framework for 4D Superconformal Anomalies,2507.16505
-
[45]
R. Bittleston and K. J. Costello,The one-loop qcdβ-function as an index,2510.26764
-
[46]
M. Henningson and K. Skenderis,The Holographic Weyl anomaly,JHEP07(1998) 023, [hep-th/9806087]
work page internal anchor Pith review Pith/arXiv arXiv 1998
-
[47]
Holography and the Weyl anomaly
M. Henningson and K. Skenderis,Holography and the Weyl anomaly,Fortsch. Phys.48 (2000) 125–128, [hep-th/9812032]
work page internal anchor Pith review Pith/arXiv arXiv 2000
-
[48]
Diffeomorphisms and Holographic Anomalies
C. Imbimbo, A. Schwimmer, S. Theisen and S. Yankielowicz,Diffeomorphisms and holographic anomalies,Class. Quant. Grav.17(2000) 1129–1138, [hep-th/9910267]
work page internal anchor Pith review Pith/arXiv arXiv 2000
-
[49]
Universal Features of Holographic Anomalies
A. Schwimmer and S. Theisen,Universal features of holographic anomalies,JHEP10(2003) 001, [hep-th/0309064]
work page internal anchor Pith review Pith/arXiv arXiv 2003
-
[50]
Chern-Simons Gravity and Holographic Anomalies
M. Banados, A. Schwimmer and S. Theisen,Chern-Simons gravity and holographic anomalies,JHEP05(2004) 039, [hep-th/0404245]
work page internal anchor Pith review Pith/arXiv arXiv 2004
-
[51]
The galileon as a local modification of gravity
A. Nicolis, R. Rattazzi and E. Trincherini,The Galileon as a local modification of gravity, Phys. Rev. D79(2009) 064036, [0811.2197]
work page internal anchor Pith review Pith/arXiv arXiv 2009
-
[52]
F. Coradeschi, P. Lodone, D. Pappadopulo, R. Rattazzi and L. Vitale,A naturally light dilaton,JHEP11(2013) 057, [1306.4601]
work page internal anchor Pith review Pith/arXiv arXiv 2013
-
[53]
Fubini,A New Approach to Conformal Invariant Field Theories,Nuovo Cim
S. Fubini,A New Approach to Conformal Invariant Field Theories,Nuovo Cim. A34(1976) 521
work page 1976
-
[54]
Witten,Global aspects of current algebra,Nuclear Physics B223(1983) 422–432
E. Witten,Global aspects of current algebra,Nuclear Physics B223(1983) 422–432
work page 1983
-
[55]
E. A. Ivanov and V. I. Ogievetsky,Inverse higgs effect in nonlinear realizations,Theoretical and Mathematical Physics25(1975) 1050–1059
work page 1975
-
[56]
A. Bilal,Lectures on Anomalies,0802.0634
work page internal anchor Pith review Pith/arXiv arXiv
-
[57]
M. Kaku, P. K. Townsend and P. van Nieuwenhuizen,Gauge theory of the conformal and superconformal group,Phys. Lett. B69B(1977) 304–308
work page 1977
-
[58]
M. Kaku, P. K. Townsend and P. van Nieuwenhuizen,Properties of conformal supergravity, Phys. Rev. D17(1978) 3179–3187
work page 1978
-
[59]
T. Kugo and S. Uehara,N= 1Supergravity and Superconformal Tensor Calculus,Prog. Theor. Phys.73(1985) 235–264, [CERN-TH-3672]
work page 1985
-
[60]
P. Di Francesco, P. Mathieu and D. S´ en´ echal,Conformal Field Theory. Springer, 1997
work page 1997
-
[61]
S. Kobayashi and K. Nomizu,Foundations of Differential Geometry, Volume I. Wiley, 1963
work page 1963
-
[62]
J. W. Milnor and J. D. Stasheff,Characteristic Classes. Princeton University Press, 1974
work page 1974
-
[63]
Nakahara,Geometry, topology and physics
M. Nakahara,Geometry, topology and physics. 2003. – 18 –
work page 2003
-
[64]
L. Alvarez-Gaum´ e and E. Witten,Gravitational anomalies,Nuclear Physics B234(1984) 269–330
work page 1984
-
[65]
L. Alvarez-Gaum´ e and P. Ginsparg,The structure of gauge and gravitational anomalies, Annals of Physics161(1985) 423–490
work page 1985
-
[66]
R. A. Bertlmann,Anomalies in quantum field theory. 1996
work page 1996
-
[67]
A. Ach´ ucarro and P. K. Townsend,A chern–simons action for three-dimensional anti–de sitter supergravity,Physics Letters B180(1986) 89–92
work page 1986
-
[68]
Witten,2+1 dimensional gravity as an exactly soluble system,Nuclear Physics B311 (1988) 46–78
E. Witten,2+1 dimensional gravity as an exactly soluble system,Nuclear Physics B311 (1988) 46–78
work page 1988
-
[69]
Three-Dimensional Gravity Revisited
E. Witten,Three-Dimensional Gravity Revisited,0706.3359
work page internal anchor Pith review Pith/arXiv arXiv
-
[70]
A. H. Chamseddine and J. Frohlich,Two-dimensional Lorentz-Weyl anomaly and gravitational Chern-Simons theory,Commun. Math. Phys.147(1992) 549–562
work page 1992
-
[71]
P. Mora, R. Olea, R. Troncoso and J. Zanelli,Transgression forms and extensions of Chern-Simons gauge theories,JHEP02(2006) 067, [hep-th/0601081]
work page internal anchor Pith review Pith/arXiv arXiv 2006
-
[72]
Gauge interactions and topological phases of matter
Y. Tachikawa and K. Yonekura,Gauge interactions and topological phases of matter,PTEP 2016(2016) 093B07, [1604.06184]
work page internal anchor Pith review Pith/arXiv arXiv 2016
- [73]
-
[74]
Spontaneously Broken Spacetime Symmetries and Goldstone's Theorem
I. Low and A. V. Manohar,Spontaneously broken space-time symmetries and Goldstone’s theorem,Phys. Rev. Lett.88(2002) 101602, [hep-th/0110285]
work page internal anchor Pith review Pith/arXiv arXiv 2002
-
[75]
Spontaneously Broken Spacetime Symmetries and the Role of Inessential Goldstones
R. Klein, D. Roest and D. Stefanyszyn,Spontaneously Broken Spacetime Symmetries and the Role of Inessential Goldstones,JHEP10(2017) 051, [1709.03525]
work page internal anchor Pith review Pith/arXiv arXiv 2017
-
[76]
E. D’Hoker and E. Farhi,Decoupling a fermion in the standard electroweak theory,Nucl. Phys. B248(1984) 59–76
work page 1984
-
[77]
G. ’t Hooft,Computation of the quantum effects due to a four-dimensional pseudoparticle, Physical Review D14(1976) 3432–3450. – 19 –
work page 1976
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