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Dictionary Completeness and Global Data

A local operator dictionary is only one layer of a holographic correspondence. Two theories may have the same local Lie algebra, perturbative fields, and correlators of neutral local operators, yet differ in their genuine line operators, allowed bundles, topological sectors, or boundary conditions. A completeness claim must therefore say which observables and sectors are mapped, how they are normalized, and which global choices define each theory.

Required background. Holographic Duality: Claims, Dictionaries, and Regimes defines the theory-pair contract, and Relational, Boundary, and Asymptotic Observables identifies the observables whose completeness is at issue.

Helpful background. Generalized Symmetries, Global Forms, and Anomalies under Duality develops the underlying QFT distinctions and includes a charge-lattice figure for the su(2)\mathfrak{su}(2) case. Additivity, Haag Duality, and Information Completeness gives a complementary operator-algebra perspective.

It helps to separate a local core from its global completion. The local core includes the operator map, couplings, correlation functions, and their domain of validity. The completion says which theory those local data belong to.

The terms in the checklist have operational meanings. The Lie algebra controls infinitesimal gauge transformations; the global form specifies which finite transformations are identified and therefore which representations and bundles exist. A line is genuine when it is defined without an attached surface; a surface-attached line may still be a useful probe, but it is not a standalone operator. A one-form symmetry acts on genuine lines, and a two-form background probes that action. An anomaly is an obstruction to gauging a symmetry while preserving all required invariances, not merely a failure of a classical current equation.

A superselection sector is always relative to a chosen observable algebra: by definition, no operator in that algebra connects distinct sectors. An interface, a defect, or an enlarged algebra may relate them, but then that enlargement is additional dictionary data. This page uses “complete” to mean complete for the declared holographic dictionary. It does not mean maximality of a local operator algebra or the quantum-gravity conjecture that every allowed gauge charge is dynamically realized.

Minimum information carried by a global holographic dictionary
LayerWhat must be recordedA comparison that can expose a mismatch
Local observablesOperator map, sources, contact-term scheme, couplings, and normalizationWard identities and normalized correlation functions
Global groupsFaithful global and gauge groups, including quotients by centersRepresentations and bundles allowed by the quotient
Extended operatorsGenuine lines, surfaces, defects, junctions, and their fusion rulesLinking, braiding, fusion, and endpoint tests
Charge dataCharge groups, screening relations, pairings, and the genuine subsetDirac or mutual-locality phases
Generalized symmetriesHigher-form and higher-group symmetries and their charged objectsBackground-field transformations and symmetry defects
AnomaliesPerturbative, global, torsion, and mixed anomaly classesInflow or partition functions on nontrivial backgrounds
Topological sectorsAllowed bundles, fluxes, discrete theta terms, and sector weightsPartition functions resolved by topology or flux
Boundary dataBoundary conditions, boundary degrees of freedom, and allowed endpointsBoundary operator and defect spectra
State spaceHilbert space or observable algebra in each sector and its superselection structureState counting and sector-changing operations
PrescriptionFixed sector, sum over sectors, gauging, state, ensemble, and measureFactorization and Fourier-transform tests
Claim domainSpacetime, topology, regulator, parameter regime, approximation, and uncertaintyA probe just outside the declared domain

This is not a demand to compute every entry before making any useful statement. It is a demand to keep the conclusion no broader than the entries actually fixed. Matching anomalies, for example, is a strong necessary test but is not sufficient for equivalence: distinct theories can share the same anomaly. The background-field and extended-operator framework is developed systematically in Gaiotto, Kapustin, Seiberg, and Willett 2015, §§2–4 and 6, Open PDF.

Electric and magnetic line charges for su(N)

Section titled “Electric and magnetic line charges for su(N)”

The cleanest counterexample uses four-dimensional gauge theories with Lie algebra su(N)\mathfrak{su}(N) and only adjoint dynamical fields. We work on spin four-manifolds and first consider flat R4\mathbb R^4 with no line insertions. This scope includes N=4\mathcal N=4 super-Yang–Mills theory. Nonspin manifolds require additional information about line statistics and discrete topological terms.

Retain only the finite center-charge data by quotienting the electric weight lattice by the root lattice and the magnetic coweight lattice by the coroot lattice. A Wilson–’t Hooft line then has a class

γ=(e,m)∈Γ=ZN×ZN.\gamma=(e,m)\in \Gamma=\mathbb Z_N\times\mathbb Z_N.

Here ee is electric NN-ality and mm is its magnetic counterpart. Taking a line γ′\gamma' once around γ\gamma produces the phase

exp⁡ ⁣[2πiN ω(γ,γ′)],ω((e,m),(e′,m′))=em′−me′(modN).\exp\!\left[\frac{2\pi i}{N}\, \omega(\gamma,\gamma')\right], \qquad \omega\bigl((e,m),(e',m')\bigr) =em'-me'\pmod N.

Two lines can both be genuine line operators in the same theory only if they are mutually local, so this phase must be one. Thus their charges must obey ω=0\omega=0 modulo NN. A complete choice of genuine center-charge classes is a maximal mutually local, or maximal isotropic, subgroup L⊂ΓL\subset\Gamma: its elements pair trivially with one another, and no further charge class can be added without violating mutual locality Aharony, Seiberg, and Tachikawa 2013, Introduction and §§1.1–1.3, Open PDF.

This finite quotient suppresses the root- and coroot-lattice labels carried by individual lines. In particular, the formula below does not say that an SU(N)SU(N) theory has no ’t Hooft lines; it says that their magnetic center-charge class is trivial.

For the simply connected group, the genuine classes are purely electric,

LSU(N)={(r,0):r∈ZN}.L_{SU(N)} =\bigl\{(r,0):r\in\mathbb Z_N\bigr\}.

In particular, the fundamental Wilson line (1,0)(1,0) is genuine. For the quotient group PSU(N)=SU(N)/ZNPSU(N)=SU(N)/\mathbb Z_N, there are NN spin-theory choices customarily denoted PSU(N)nPSU(N)_n, with

Ln={(nr,r)(modN):r∈ZN},n=0,1,…,N−1.L_n =\bigl\{(nr,r)\pmod N:r\in\mathbb Z_N\bigr\}, \qquad n=0,1,\ldots,N-1.

The generator is a magnetic line for n=0n=0 and a dyonic line for n≠0n\ne0. The label nn is discrete theta-like data: a 2π2\pi shift of the ordinary theta angle permutes these theories rather than acting trivially on a fixed line spectrum. These statements, including the composite-NN completeness condition, are derived in Aharony, Seiberg, and Tachikawa 2013, §2.1 and §6.2, Open PDF.

The N=2N=2 case is a useful picture in words. There are three maximal choices:

LSU(2)={(0,0),(1,0)},LSO(3)+={(0,0),(0,1)},LSO(3)−={(0,0),(1,1)}.\begin{aligned} L_{SU(2)}&=\{(0,0),(1,0)\},\\ L_{SO(3)_+}&=\{(0,0),(0,1)\},\\ L_{SO(3)_-}&=\{(0,0),(1,1)\}. \end{aligned}

They select an electric, magnetic, or dyonic nontrivial line, respectively. The ++ and −- labels here use the spin-manifold convention; on a nonspin manifold the line spins and refined topological terms must also be declared.

The distinction is invisible to correlators of local operators on R4\mathbb R^4 without extended insertions. It becomes visible immediately to a line probe, on a compactification where a wrapped line becomes local, or on a manifold carrying a nontrivial bundle. “Same local correlators” therefore means same tested local sector, not “the same theory on every spacetime.”

The standard N=4\mathcal N=4 example makes the holographic consequence concrete. Type-IIB string theory on AdS5×S5\mathrm{AdS}_5\times S^5 with NN units of five-form flux contains the Neveu–Schwarz and Ramond–Ramond two-form gauge fields, B2B_2 and C2C_2. Normalize them so that a unit fundamental- or D-string worldsheet contributes exp⁡(i∫B2)\exp(i\int B_2) or exp⁡(i∫C2)\exp(i\int C_2); their periods are then 2π2\pi. In Witten’s Euclidean convention, the five-dimensional low-energy action includes

StopE=−iN2π∫XC2∧dB2.S_{\mathrm{top}}^{E} =-\frac{iN}{2\pi}\int_X C_2\wedge dB_2.

This is only the topological part of the effective action, with its global definition understood in differential cohomology, but it is precisely the part that remembers finite flux data. The first-order term makes the two boundary fields a conjugate pair, so a boundary condition chooses a polarization: which member is held fixed and which is allowed to fluctuate. Dirichlet boundary conditions fix a boundary value as a background source; Neumann boundary conditions instead sum over that value while fixing its conjugate response, thereby changing which complementary one-form symmetry is global or gauged. Because XX has a boundary, replacing C2∧dB2C_2\wedge dB_2 by B2∧dC2B_2\wedge dC_2 changes the action by a boundary term; that term belongs to the variational problem and must be fixed before “Dirichlet” and “Neumann” are assigned Witten 1998, Introduction and §§2–3, Open PDF.

A fundamental string couples to B2B_2 and can end on a Wilson line; a D-string couples to C2C_2 and can end on an ’t Hooft line. More generally, a (p,q)(p,q) string endpoint carries the corresponding dyonic charge. The allowed boundary endpoints must reproduce the chosen subgroup LL. In modern language, changing the boundary polarization of the two-form topological sector changes the global completion of the boundary theory even when the propagating supergravity spectrum is unchanged Witten 1998, §5, Open PDF.

The two simplest polarizations make the result explicit. Use the boundary action and notation of Bhardwaj et al., with b2b_2 descending from B2B_2 and c2c_2 from C2C_2. Dirichlet b2b_2 with Neumann c2c_2 gives the SU(N)SU(N) theory and its electric ZN\mathbb Z_N one-form symmetry. A wrapped D5-brane is a baryon vertex on which NN fundamental strings can end. Exchanging the boundary conditions—Dirichlet c2c_2 with Neumann b2b_2—gives PSU(N)0PSU(N)_0 and its magnetic ZN\mathbb Z_N one-form symmetry; a wrapped NS5-brane screens NN D-strings. Mixed polarizations encode the other discrete-theta variants Bhardwaj et al. 2023, §6.2, Open PDF.

What the first holographic application must distinguish
DatumSU(N)PSU(N) with label n
Local gauge algebrasu(N)su(N)
Local adjoint correlators on flat spaceCan agree at the same local coupling and theta value
Genuine center-charge generatorElectric class (1, 0)Dyonic class (n, 1)
Fundamental Wilson lineGenuineNot a standalone genuine line
Bundle sectorsBundles lift to SU(N)Non-liftable bundles with discrete magnetic flux are allowed
One-form symmetry realizationElectric center symmetryMagnetic or dyonic realization determined by n
Bulk datum that must changeBoundary polarization and allowed endpoints in the two-form topological sector

The table does not assert that the two boundary theories require different local supergravity Lagrangians. Its point is the opposite: the same propagating bulk fields do not determine the boundary global form. The topological sector, its boundary condition, and its allowed string endpoints are indispensable dictionary entries. Within asymptotically AdS quantum gravity with a CFT dual, Harlow and Ooguri analyze compact internal, splittable boundary symmetries and compact long-range bulk gauge symmetries; the reverse construction also needs assumptions about a semiclassical bulk. Their result constrains faithful groups and charged objects, but it does not prove completeness of an arbitrary holographic dictionary Harlow and Ooguri 2021, §§4.4–5 and 8, Open PDF.

Background fields and sector sums are part of the equality

Section titled “Background fields and sector sums are part of the equality”

Let BB be a flat discrete two-form background, or cocycle, for the electric ZN\mathbb Z_N one-form symmetry of the SU(N)SU(N) theory. Its cohomology class records the obstruction to lifting a PSU(N)PSU(N) bundle to an SU(N)SU(N) bundle. The source-dependent object

ZSU(N)[M;B]Z_{SU(N)}[M;B]

is a family of background-resolved, or twisted, partition functions. Gauging the one-form symmetry constructs a quotient theory by a finite sum of the schematic form

ZPSU(N)n[M]=1N(M)∑[B]∈H2(M,ZN)ZSU(N)[M;B] eiSn[B].Z_{PSU(N)_n}[M] =\frac{1}{\mathcal N(M)} \sum_{[B]\in H^2(M,\mathbb Z_N)} Z_{SU(N)}[M;B]\,e^{iS_n[B]}.

Here Sn[B]S_n[B] is the allowed discrete topological phase and N(M)\mathcal N(M) includes the finite-gauge-theory normalization appropriate to the chosen convention. Its detailed cochain formula depends on the topology and on spin versus nonspin refinements; suppressing those details is harmless only if the equality itself is explicitly labeled schematic. Fixing B=0B=0, summing over BB, and Fourier transforming among flux sectors are different operations Aharony, Seiberg, and Tachikawa 2013, §§6.1–6.4, Open PDF.

This distinction is not a statistical ensemble over unrelated Hamiltonians. It is a gauging or sector prescription within a specified theory construction. The next page, Fixed-Theory, Ensemble, and Superselection Claims, separates these operations and gives their factorization tests.

A researcher can test a proposed global dictionary without assuming the desired conclusion.

  1. Declare the domain. Record the spacetime topology and tangential structure—for example, oriented, spin, or nonspin—together with boundary conditions, couplings, regulator, approximation, and whether defects are inserted.
  2. Fix each theory. State the faithful groups, genuine extended operators, charge group, pairing, allowed bundles, topological actions, and sector-sum prescription on both sides.
  3. Map the data. Give an integral pairing-preserving map of charge classes, a map of backgrounds and anomalies, and a map of boundary conditions and allowed endpoints.
  4. Choose a resolving probe. Select a charge that belongs to exactly one of the two proposed genuine subsets, or a bundle sector included on only one side.
  5. Compute the same object. Compare either the linked-line phase, a background- or flux-resolved partition function, or the amplitude for the corresponding bulk object to end at the boundary. Use the same normalization and counterterm convention.
  6. State the surviving claim. If the resolving probe fails, retain only the common local or sectoral statement; do not call the dictionary complete.

For SU(N)SU(N) versus PSU(N)nPSU(N)_n, the fundamental electric class (1,0)(1,0) is already a resolving probe: it belongs to LSU(N)L_{SU(N)} but not to LnL_n. Conversely, (n,1)(n,1) belongs to LnL_n but not to LSU(N)L_{SU(N)}. Agreement of every tested local adjoint correlator cannot repair either mismatch.

Treating the Lie algebra as the gauge group. The algebra determines local gauge bosons, but the global group determines representations, bundles, and genuine Wilson lines. Write both.

Calling every line with a label “genuine.” A non-genuine line requires an attached surface or other auxiliary data. Such an object is useful, but it is not interchangeable with a standalone line operator.

Comparing a fixed sector with a sector sum. Equality at B=0B=0 is not equality after summing over [B][B]. State the measure, phases, and normalization before comparing partition functions.

Using anomaly matching as a proof of duality. Anomalies are robust necessary data. They do not determine all operator products, spectra, sector weights, or dynamics.

Forgetting the manifold class. The simple PSU(N)nPSU(N)_n presentation above assumes spin four-manifolds. Nonspin manifolds can refine theta periodicities and line statistics, so the dictionary must record those choices rather than extrapolate silently.

Show directly that both LSU(N)L_{SU(N)} and LnL_n are mutually local. Why are they maximal isotropic subgroups of Γ=ZN2\Gamma=\mathbb Z_N^2?

Solution

For two elements (r,0)(r,0) and (r′,0)(r',0) of LSU(N)L_{SU(N)},

ω((r,0),(r′,0))=0.\omega\bigl((r,0),(r',0)\bigr)=0.

For two elements (nr,r)(nr,r) and (nr′,r′)(nr',r') of LnL_n,

ω((nr,r),(nr′,r′))=nrr′−rnr′=0(modN).\omega\bigl((nr,r),(nr',r')\bigr) =nrr'-rnr'=0\pmod N.

For the nondegenerate finite pairing,

∣L∣ ∣L⊥∣=∣Γ∣=N2.|L|\,|L^\perp|=|\Gamma|=N^2.

Isotropy gives L⊆L⊥L\subseteq L^\perp, hence ∣L∣≤N|L|\le N. Each displayed subgroup has exactly NN elements, so L=L⊥L=L^\perp and neither can be enlarged while remaining isotropic. This argument also works when NN is composite.

For N=4N=4, list the genuine center-charge classes of SU(4)SU(4) and PSU(4)1PSU(4)_1. Give one line probe that distinguishes the two theories in each direction.

Solution

The two subsets are

LSU(4)={(0,0),(1,0),(2,0),(3,0)},L_{SU(4)}=\{(0,0),(1,0),(2,0),(3,0)\},

and

L1={(0,0),(1,1),(2,2),(3,3)}.L_1=\{(0,0),(1,1),(2,2),(3,3)\}.

The fundamental Wilson class (1,0)(1,0) is genuine in SU(4)SU(4) and not in PSU(4)1PSU(4)_1. The dyonic class (1,1)(1,1) is genuine in PSU(4)1PSU(4)_1 and not in SU(4)SU(4). Either probe distinguishes the global theories although local adjoint correlators on R4\mathbb R^4 can agree.

Suppose a proposed dictionary equates ZA[M;B=0]Z_A[M;B=0] with

ZB[M]=1N(M)∑[B]ZA[M;B]eiS[B].Z_B[M]=\frac{1}{\mathcal N(M)} \sum_{[B]}Z_A[M;B]e^{iS[B]}.

What additional statement would be needed for this to be an equality of the displayed objects rather than an accidental equality in one sector?

Solution

The proposal must specify a gauging or sector transform that maps the full family ZA[M;B]Z_A[M;B] to ZB[M]Z_B[M], including the set of summed classes, the phase S[B]S[B], and the normalization N(M)\mathcal N(M). Equality of the B=0B=0 term alone cannot establish equality with the sum. It would suffice only after proving, in the declared domain, that all other weighted contributions vanish or combine to the required value—a much stronger and explicitly testable statement.

This page supplies a refutation-oriented completeness test; passing the listed checks does not prove that no relevant observable remains unexamined. Symmetry and Gauge Theory, Conformal Field Theory and the Bootstrap, and Supersymmetry and Duality own the detailed symmetry, CFT, and protected-sector constructions. Boundary Global Symmetry, Bulk Gauge Symmetry, and Global Form develops the Chapter 3 dictionary. Charge-Lattice Completeness and Spectrum Tests owns the distinct Chapter 25 charge-completeness question, and Mathematical QFT owns theorem-level formulations. Nonperturbative Definition and Completion Criteria asks the separate question of whether a proposed construction defines all of its claimed observables at finite coupling and finite NN.

Evidence cutoff. Examples and literature-status statements are fixed to 25 July 2026. The gauge-theory and topological-field-theory formulas above are established results in the stated domain; the cutoff does not turn the checklist into a proof of any complete holographic equivalence.

The chapter overview contains the structure diagram and validity and failure diagram. They are embedded there once so that their shared chapter-level context is not repeated on every article.

For the chapter-wide comparison of assumptions, counterevidence, falsifiers, and claim ceilings, see the claim-domain table.

  • Aharony, Ofer, Nathan Seiberg, and Yuji Tachikawa. “Reading between the Lines of Four-Dimensional Gauge Theories.” Journal of High Energy Physics 08 (2013): 115. DOI. Open PDF.
  • Bhardwaj, Lakshya, Lea E. Bottini, Ludovic Fraser-Taliente, Liam Gladden, Dewi S. W. Gould, Arthur Platschorre, and Hannah Tillim. “Lectures on Generalized Symmetries.” arXiv:2307.07547 [hep-th] (2023). Open PDF.
  • Gaiotto, Davide, Anton Kapustin, Nathan Seiberg, and Brian Willett. “Generalized Global Symmetries.” Journal of High Energy Physics 02 (2015): 172. DOI. Open PDF.
  • Harlow, Daniel, and Hirosi Ooguri. “Symmetries in Quantum Field Theory and Quantum Gravity.” Communications in Mathematical Physics 383 (2021): 1669–1804. DOI. Open PDF.
  • Witten, Edward. “AdS/CFT Correspondence and Topological Field Theory.” Journal of High Energy Physics 12 (1998): 012. DOI. Open PDF.

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