Falsifiers, Negative Results, and Counterexamples
A negative result has force only against a proposition precise enough to be wrong. It must name the theory or proposed dual pair, state and sector, observable and dictionary entry, normalization, domain, limit order, admitted corrections, and uncertainty model. Failure of a solver or approximation therefore does not automatically falsify a duality; conversely, one counterexample can decisively refute a genuinely universal claim.
Required background. Holographic Duality: Claims, Dictionaries, and Regimes identifies the claim, while Evidence Programs for Holographic Duality identifies the test and its assumptions.
Helpful background. Duality Checks, Evidence Independence, Status, and Failure Modes gives the general duality setting. EFT Truncation Errors and Breakdown Diagnostics distinguishes expected breakdown from contradiction.
Reading path. First learn what each kind of failure excludes, then use the six-step decision rule. The central application separates a finite-gap failure, an exact inconsistency, and a failed extrapolation. The final sections give an adversarial approximation test, genuine counterexamples, and exercises.
What a failed test can rule out
Section titled “What a failed test can rule out”A negative result is any outcome that fails to support the proposed conclusion; it may be decisive, inconclusive, or merely uninformative. A falsifier is a reproducible contradiction obtained inside the declared domain of a frozen proposition. A counterexample satisfies the premises of a universal or sufficient-condition claim while violating its conclusion. A method failure shows that the calculation or inference procedure is unreliable without yet deciding the physics.
The distinction can be made mathematically. Let be the set of values allowed by proposition in domain , after every admitted correction, nuisance parameter, and licensed limiting case has been included. An exact result contradicts if
This is a formal contradiction. A stronger, perturbatively robust exclusion has positive distance from the allowed set,
or equivalently lies outside its closure. The distinction matters for a claim such as : the exact result contradicts it even though arbitrarily small positive values approach zero. For a finite-precision observation with confidence set , the operational exclusion condition is instead
For example, if allows while the 95% confidence set is , the sets are disjoint and is excluded at that stated confidence level. If a justified calibration uncertainty enlarges the allowed set through , the overlap makes the result unresolved. The exclusion is conditional on the confidence-set construction, coverage, likelihood, nuisance model, and systematic-error treatment; it is not a deductive proof that nature lies outside . Test power instead controls what may be inferred from a non-exclusion.
| Failure type | Proposition challenged | What must be controlled | What may survive |
|---|---|---|---|
| Exact-data or dictionary contradiction | Candidate exact data violate consistency, or two quantities claimed to be exact images disagree | Complete data or a rigorous certificate; for a map, also the theory pair, state, sector, normalization, counterterms, and continuation | Other candidate data, dictionary entries, or a narrower sectoral map |
| Absence of the claimed regime | A necessary condition for the advertised bulk description cannot be met | Scale hierarchy, spectrum, kinematics, phase, and order of limits | The boundary theory and a stringy, higher-spin, or otherwise non-Einstein bulk |
| Error-bound violation | An in-domain remainder exceeds an independently justified bound | Uniformity of the bound, numerical and experimental uncertainty, and omitted terms | The leading mechanism with weaker precision or additional corrections |
| Counterexample to sufficiency | The proposed premises hold but their claimed conclusion fails | Every premise, quantifier, and stated scope of the implication | The premises as necessary conditions or heuristic indicators |
| Computational-method failure | A solver, truncation, saddle choice, or extrapolation does not support its reported answer | Benchmarks, precision and cutoff refinement, alternative implementations, and out-of-fit prediction | The approximation and the physical proposition tested by another method |
These rows are not automatically a ladder. A method failure does not propagate to a physical claim, and failure of one dictionary entry does not propagate to an exact dual pair without an additional completeness premise. The chapter overview’s validity-and-failure diagram shows this branching structure.
Freeze the proposition before naming a falsifier
Section titled “Freeze the proposition before naming a falsifier”A reproducible classification takes six steps.
- Write the proposition with its quantifiers. “All unitary CFTs have property ” and “this family approaches as ” are different claims.
- Freeze the physical target. Record the theories, state or ensemble, sector, observable, dictionary map, normalization, regulator, and ordered limits.
- Freeze the validity domain. State the energy and coupling window, retained orders, spectral assumptions, and the phase in which the comparison is licensed.
- Predeclare uncertainty and the decision rule. Include correlated systematics and theory error; specify what counts as passing, failing, or remaining unresolved.
- Run controls and an independent check. Refine cutoffs and precision, vary nuisance choices only within their declared ranges, benchmark special limits, and reproduce the result analytically or with independent code where possible.
- Name the narrowest failed proposition and strongest survivor. Also state the alternative explanation and the next observation that would distinguish it.
If the observable, domain, or tolerance can still move after the result is seen, stop at unresolved discrepancy. The preceding page on Evidence Independence, Circularity, and Double Counting explains how shared assumptions or calibration data can make apparently independent reproductions fail together.
A useful final sentence has the form: “Under assumptions in domain , result excludes proposition at precision ; claim survives, and test distinguishes the leading alternative.” It is deliberately more informative than “the model failed.”
Worked application: finite gap, exact inconsistency, or failed extrapolation?
Section titled “Worked application: finite gap, exact inconsistency, or failed extrapolation?”Use a three-part AdS/CFT benchmark to make the classification reproducible. On the Euclidean boundary, take a Hermitian scalar of dimension normalized by
Let be the AdS radius and the matrix-rank parameter. The global (+---) convention applies after Lorentzian continuation. The numbers below are analytic or synthetic test inputs—not observations and not evidence against a real duality—and they freeze three propositions:
- : the normalized discrepancy is , with , and obeys throughout ;
- : the proposed complete identical-scalar data contain only the identity, so , and satisfy exact crossing throughout the Euclidean domain; the adversarial test point is , hence ;
- : the exact synthetic sequence given below is fitted by over each declared three-point window, and the intercept estimates the large- target within .
The analytic fixtures have no sampling uncertainty; displayed rounding is below . Their controls are direct substitution, interchange of the two crossing channels, and evaluation at both passing and failing energies. The numerical branch has no measurement noise but does have model-selection uncertainty, tested by the preregistered fit windows and a held-out or subleading-term check. Thus is a conditional EFT error claim, an exact consistency claim, and a computational inference. A physical application would replace these synthetic inputs with measured or independently calculated quantities and their full covariance.
Finite gap: the Einstein window can lose control
Section titled “Finite gap: the Einstein window can lose control”Let be the bulk mass associated with the lightest single-trace primary of spin . In a parametrically large-gap limit,
An observable may then receive a schematic higher-spin correction
where , the exponent, and other admitted terms depend on the observable and EFT operators. When , gap power counting can support a controlled Einstein window. When , it no longer guarantees suppression; the actual correction can still be small if its coefficient vanishes or is symmetry-suppressed. Data there cannot refute an approximation whose declared domain ended below the gap. They do refute if it promised small error through that energy and the discrepancy survives a computed remainder and uncertainty budget. The exact CFT and a bulk completion containing string or higher-spin states may remain fully viable; see Higher-Spin Gaps and Einstein-Regime Obstructions and Corrections, Nonuniform Limits, and Failure.
In the frozen benchmark, , , and . Direct substitution gives
The first point satisfies the declared tolerance, while the second violates it inside the advertised endpoint. This rejects the benchmark’s , not . The calculation is exactly reproducible because the discrepancy generator was defined as part of the fixture; it does not assert that a real CFT has coefficient one.
Causality makes the distinction concrete. Write the four- and six-derivative graviton-coupling coefficients as and . In the weakly coupled, tree-level analysis of Camanho et al. 2016, § 1, pp. 2–4; §§ 3.3–4.4, pp. 20–34; §§ 5.2–5.5, pp. 36–43; § 8, pp. 47–49, causality requires an infinite tower of higher-spin states at parametrically related scales
A finite collection does not suffice; in string theory, the tower Reggeizes the amplitude and removes the time advance. The result excludes the claimed low-energy regime, not a UV completion that supplies the tower. The large-gap route from CFT data to perturbative bulk locality is developed under explicit assumptions by Heemskerk et al. 2009, §§ 3–4, pp. 10–25.
Exact CFT consistency: a certificate must reach the full claim
Section titled “Exact CFT consistency: a certificate must reach the full claim”The identity-only benchmark already gives an exact contradiction without a solver. Identical-scalar crossing requires
At the frozen point, the residual is
Interchanging and flips the sign, which checks the channel convention. The symmetric point would give zero even for this inconsistent candidate and is therefore not a discriminating control. The nonzero exact residual rejects the benchmark’s while saying nothing about complete data sets that contain the required nonidentity operators.
For a general identical-scalar exclusion, absorb the identity contribution into and write
Suppose a rigorously validated linear functional satisfies
for every operator allowed by the frozen spectrum assumptions. Applying makes the left side at least one, so the assumed data set cannot solve crossing. This is an exact contradiction of that CFT-data proposition—and hence of every dictionary that requires those data—only when block errors, the continuous positivity ranges, and numerical roundoff are enclosed by a valid certificate. A residual from a truncated OPE sum, or a solver status that changes with derivative order or precision, instead diagnoses truncation or method failure. The crossing and positivity page derives the sum rule; solver certificates and precision and error budgets develop the numerical controls. The separating-functional logic is reviewed in Simmons-Duffin 2017, § 10.4, pp. 54–55, while current algorithms and software are surveyed by Rychkov and Su 2024, §§ II–VII.
Large-N extrapolation: fit instability is not a physical contradiction
Section titled “Large-N extrapolation: fit instability is not a physical contradiction”Use the transparent, dimensionless calibration sequence
These are synthetic exact values, not CFT data. Fit each three-point window by unweighted least squares to the misspecified model , omitting the term. The only uncertainty here is structural: the preregistered stability tolerance is .
| Values of N | Fitted intercept A | Absolute error from 1 | Result at tolerance 0.01 |
|---|---|---|---|
| 2, 3, 4 | 1.310248 | 0.310248 | Fails |
| 4, 6, 8 | 1.019391 | 0.019391 | Fails |
| 6, 8, 12 | 1.003799 | 0.003799 | Passes this check |
The middle and late intercepts differ by , already larger than the declared tolerance. Because the exact generating rule is known, the omitted term is the diagnosis. In real data one must compare plausible exponents and subleading terms, propagate covariance, withhold points for prediction, and seek an independent calculation. Until those checks stabilize, only fails; no exact finite- theory or duality has been tested. A real large-central-charge modular-bootstrap analysis uses correspondingly careful language: its asymptotic gap is reported as numerical evidence from extrapolation, with the explicit caveat that a stronger limiting bound cannot be ruled out Afkhami-Jeddi, Hartman, and Tajdini 2019, § 1, pp. 2–3; § 5.2, pp. 14–16.
| Observation | Classification | Narrowest rejected proposition | Strongest survivor and decisive follow-up |
|---|---|---|---|
| No higher-spin gap large enough for the promised energy window | Absence of the claimed regime | The advertised Einstein window | Exact CFT and non-Einstein bulk; identify the light tower and retest |
| In-domain discrepancy exceeds an independently proved EFT remainder | Error-bound violation | The stated precision guarantee | The leading EFT mechanism; include omitted terms or narrow the domain |
| Validated functional has a strictly positive identity value and is nonnegative on every allowed nonidentity block | Exact-data contradiction | The proposed CFT data plus their spectrum assumptions | Other boundary data or theories; relax one explicit assumption and recertify |
| Crossing residual moves under cutoff or precision refinement | Computational-method failure | The reported numerical conclusion | The CFT proposition; obtain a stable, independently checked certificate |
| Large-N intercept moves beyond its fit tolerance | Computational-method failure | The chosen extrapolation model and error bar | All exact finite-N data; add subleading terms and predict held-out points |
Push a controlled approximation past its boundary
Section titled “Push a controlled approximation past its boundary”An adversarial validity test should cross a known boundary on purpose. Consider the exactly solvable response
For , the independently proved uniform contract
is valid. If a measured residual has total absolute uncertainty , then
whereas
The gap between these two conditions is unresolved. This interval rule avoids converting a central-value fluctuation into a false failure.
| Advertised contract | Epsilon | Exact remainder | Advertised band | Classification |
|---|---|---|---|---|
| K = 2 through epsilon = 0.5 | 0.40 | 0.2667 | 0.3200 | Compatible in-domain |
| K = 2 through epsilon = 0.5 | 0.60 | 0.9000 | 0.7200 | Outside the licensed domain; expected breakdown |
| K = 1 through epsilon = 0.5 | 0.40 | 0.2667 | 0.1600 | Advertised error guarantee is false |
The second row is the required stop rule: once , even an exactly reproduced excess cannot be promoted to a contradiction of the underlying response. The third row is different because the false bound was claimed inside its domain. A fitted envelope would not suffice as an independent proof of ; the guarantee must come from a theorem, convergent representation, interval calculation, or another derivation not calibrated on the same test points.
For the finite-gap QFT record above, the analogous control parameter is and would be the normalized observable reconstructed from the boundary correlator. A real EFT calculation must independently derive its own , , operator content, and uncertainty budget. The rational response is a unit test of the decision rule; it does not manufacture a remainder theorem for the QFT observable.
Counterexamples test sufficiency and universality
Section titled “Counterexamples test sufficiency and universality”Large- factorization and large central charge do not suffice for an Einstein bulk. At , the singlet sector of the vector model contains conserved currents of every even spin, so there is no large higher-spin gap. This is a counterexample to the proposed sufficiency of “large plus factorization,” not to holography. Klebanov and Polyakov’s original proposal pairs the model with a non-Einstein higher-spin bulk; the boundary spectrum alone supplies the counterexample here, without requiring a claim about the full proposal’s current status Klebanov and Polyakov 2002, §§ 1–2, pp. 1–5. The detailed comparison belongs to Necessary, Sufficient, and Heuristic Bulk Criteria.
A counterexample can also defeat a sharp observable conjecture without threatening its successful limiting regime. For the thermal state of a top-down four-dimensional gauge theory, the controlled hierarchy
makes the negative curvature-squared correction dominate the positive finite-coupling correction:
The ratio is therefore below the proposed universal bound at sufficiently large finite within this hierarchy Kats and Petrov 2009, § 1, eqs. (1.3)–(1.6), pp. 1–3. What fails is universality of the bound. The leading Einstein-gravity result and the holographic dictionary used to calculate the correction are not falsified.
What survives and what should be tested next
Section titled “What survives and what should be tested next”Every accepted negative result should end with a scoped downgrade and a next test.
- Method failure: preserve the physical proposition; benchmark, refine, or replace the method.
- Approximation failure: preserve the underlying model; add the omitted orders or narrow the domain.
- Dictionary-entry contradiction: reject that map under the frozen conventions; test an independent observable and inspect global or sector data.
- Absent Einstein regime: preserve a possible non-Einstein bulk; search for the light tower or nonlocal scale responsible.
- Counterexample to sufficiency: weaken the criterion to necessary or heuristic only if that weaker statement is separately supported.
- Exact-pair contradiction: exclude the specified pair only after the quantities and map are exact; other dualities do not inherit the failure.
The chapter overview also provides the compact claim-domain comparison. “Holography” and “quantum gravity” are research frameworks rather than single universally quantified predictions, so no solver residual, failed EFT window, or isolated counterexample can falsify either umbrella term.
Common pitfalls
Section titled “Common pitfalls”Moving the domain after seeing the answer. A validity window narrowed only after a mismatch makes the test non-discriminating. Predeclare the domain and treat a justified later change as a new proposition.
Calling a truncated crossing residual exact. A finite OPE truncation lacks the omitted positive tail unless it is rigorously bounded. Instability under derivative order, precision, or spectrum discretization is a method diagnostic, not a CFT contradiction.
Treating expected breakdown as contrary evidence. A perturbative excess beyond its licensed coupling, a large- fit at small , or a saddle expansion across a phase change says no more than the approximation promised.
Turning non-observation into universal absence. A null search excludes only the parameter region in which its sensitivity and power were quantified. Unseen sectors outside that region remain undecided.
Hiding shared systematics in several small error bars. Correlated normalization, calibration, regulator, or model errors do not become independent by appearing in different calculations. Profile or bound them jointly before claiming reproduction.
Exercises
Section titled “Exercises”A calculation claims that, in a fixed state, sector, and normalization, an Einstein EFT satisfies
for . Two independently implemented, cutoff-stable calculations find a residual with certified total absolute error at most at , and with certified total absolute error at most at . Give an end-to-end classification: target, domain, uncertainty rule, controls, narrowest rejected proposition, strongest survivor, leading alternative, and next discriminating test.
Solution: write the complete scoped result
The frozen target is the displayed observable comparison in the specified state, sector, and normalization; its domain ends at . At , the conservative lower residual is , and the independent, cutoff-stable implementations supply the stated controls. This is an in-domain error-bound violation of the advertised Einstein-EFT precision. The result lies outside the contract and has no falsifying force.
A complete report is: “Under the stated map, state, sector, and normalization for , the reproduced residual excludes the Einstein-EFT error claim at the reported uncertainty; the exact CFT, a holographic relation, and a non-Einstein bulk survive. A missing higher-derivative contribution or light state is the leading alternative, and adding the first omitted operator while independently measuring the higher-spin gap is the next discriminating test.”
For the fixture , , and , evaluate the schematic correction at and . Classify both results.
Solution: test the finite-gap window
The estimates are and . In the frozen fixture, the first is compatible with the tolerance and the second is an in-domain error-bound violation that rejects . In a real theory, reaching only removes parametric suppression; the coefficient and full error budget still determine the correction. Neither result contradicts exact CFT consistency or a bulk completion with the higher-spin tower restored.
A numerical crossing residual changes strongly as derivative order and arithmetic precision are raised. Two independently interval-validated functionals later reproduce a strict positivity certificate over the complete assumed spectrum. Classify the two stages.
Solution: separate solver behavior from an exact certificate
The moving residual is computational-method failure, so the proposed CFT data remain undecided. The independently validated separating functionals exclude the frozen spectrum hypothesis. They do not exclude CFTs outside those assumptions or prove that any surviving point is realized.
For the exact response , verify the rows at and for the contract , .
Solution: test the remainder bound
At , and , so the in-domain bound passes. At , exceeds , but the point is outside the declared domain. This is expected breakdown, not a failure of the exact response.
A large- theory factorizes but has an unbounded light higher-spin tower. Separately, a top-down finite- theory gives . What does each counterexample reject?
Solution: identify the quantified conclusion
The higher-spin example rejects large- factorization as sufficient for an Einstein bulk; a higher-spin holographic description may survive. The viscosity example rejects the proposed universal lower bound; it preserves both the leading Einstein value and the holographic calculation that reveals the correction.
Current boundary and handoffs
Section titled “Current boundary and handoffs”The benchmark cases above classify established logical possibilities; they do not adjudicate every live claim. Domain-specific counterexamples remain with their scientific chapters, theorem-level countermodels belong to Mathematical QFT, and new negative results and responses belong in Holography and Quantum Gravity Research. The next page, Claim Status, Freshness, and Research Handoffs, explains how a scoped result changes a living claim assessment.
Evidence cutoff. The literature check for this page is current through 27 August 2026. A material method revision, failed reproduction, or changed data release should trigger an earlier reassessment of the affected claim.
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.
References
Section titled “References”- Afkhami-Jeddi, Nima, Thomas Hartman, and Amirhossein Tajdini. 2019. “Fast Conformal Bootstrap and Constraints on 3d Gravity.” Journal of High Energy Physics 05, 087. DOI; Open PDF.
- Camanho, Xian O., José D. Edelstein, Juan Maldacena, and Alexander Zhiboedov. 2016. “Causality Constraints on Corrections to the Graviton Three-Point Coupling.” Journal of High Energy Physics 02, 020. DOI; Open PDF.
- Heemskerk, Idse, João Penedones, Joseph Polchinski, and James Sully. 2009. “Holography from Conformal Field Theory.” Journal of High Energy Physics 10, 079. DOI; Open PDF.
- Kats, Yevgeny, and Pavel Petrov. 2009. “Effect of Curvature Squared Corrections in AdS on the Viscosity of the Dual Gauge Theory.” Journal of High Energy Physics 01, 044. DOI; Open PDF.
- Klebanov, Igor R., and Alexander M. Polyakov. 2002. “AdS Dual of the Critical O(N) Vector Model.” Physics Letters B 550, 213–219. DOI; Open PDF.
- Rychkov, Slava, and Ning Su. 2024. “New Developments in the Numerical Conformal Bootstrap.” Reviews of Modern Physics 96, 045004. DOI; Open PDF.
- Simmons-Duffin, David. 2017. “TASI Lectures on the Conformal Bootstrap.” In New Frontiers in Fields and Strings, 1–74. Singapore: World Scientific. DOI; Open PDF.