§ 13.21updated 2026-06-08
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OP-46: emergent LORENTZIAN geometry from a non-CKV modular flow? (the verdict-flipping move)
Status: ATTEMPT executed — the single move that could flip OP-46 clause (iii) (derive an emergent Lorentzian metric + boost/horizon from a genuinely non-symmetric modular flow via the two named escape readouts: modular-Berry holonomy, and Lorentzian/causal NCG spectral distance) is carried out. Verdict DOES NOT FLIP, but the obstruction is promoted from a single-readout near-no-go (iter-4) toward a readout-independent one: the Lorentzian-signature + causal-order output is re-imported, not generated on every readout currently on the table. Net new: the modular-Berry route IS the first surveyed construction to cross the N4 signature barrier (genuinely Lorentzian kinematic space) — but only from the symmetric vacuum, so it CONFIRMS rather than refutes the iter-4 finding. Last updated: 2026-06-08 Iteration: 5
This note executes the iteration-4 open subquestion #1 of 2026-06-08-iter4-modular-circularity.md ("is there a non-CKV readout — modular Berry curvature / quantum information metric, or a Lorentzian Connes spectral distance — under which a genuinely non-symmetric state's modular data yields a Lorentzian metric, escaping the Sorce gate?"). Iter-4 closed the standard stress-tensor-flux readout conditionally; iter-5 attacks the two readouts that iter-4 explicitly left as the live escape, confronting GAP-NCG-LORENTZIAN-SIGNATURE head-on.
Scope honesty (folded from the four referee verdicts on this track). The strengthened claim below is not a proved universal no-go. Exactly one readout (stress-tensor flux, via the Sorce CKV theorem) carries a conditional near-no-go; the modular-Berry and Lorentzian-NCG readouts deliver an empirical-survey saturation ("every surveyed construction re-imports signature / causal order"), and the Lorentzian-NCG case is explicitly OPEN, not forbidden (no Lorentzian reconstruction theorem exists). The aggregate is best stated as saturation across all three readouts on the table, tagged
[INFERENCE], not an in-principle no-go on each. Underlying facts are web-verified; the unification step is supplied here.
Goal
Attempt the single move that would flip OP-46's headline verdict on clause (iii): derive an emergent Lorentzian (not merely Riemannian) metric plus a boost/Killing + horizon structure as the genuine OUTPUT of an pair whose modular flow is genuinely non-symmetric (non-Bunch–Davies, non-Hadamard, non-conformal-Killing), using either (b) modular-Berry holonomy / the information metric, or (a/c) a Lorentzian / causal Connes spectral distance. [goal]
Concretely:
- Test whether the modular-Berry curvature defines a metric, and whether its signature is Lorentzian as output — or whether the Lorentzian content is inherited from a symmetry-distinguished state.
[goal] - Test whether a Lorentzian/causal spectral triple delivers Lorentzian signature + causal order as output, or installs it by hand (fundamental symmetry / time-orientation form / foliation / twist).
[goal] - Decide whether the iter-4 single-readout near-no-go upgrades to a readout-independent one, and name precisely what remains live.
[goal]
Setup (real math)
Standard algebraic data : a von Neumann algebra with cyclic-separating vector , Tomita operator , modular Hamiltonian , and modular flow
a KMS automorphism group at w.r.t. . [ESTABLISHED] (Tomita–Takesaki; ../domains/mathematics.md.)
Iter-4 closure (the gate this note tries to bypass). Under the standard stress-tensor-flux readout
the Sorce CKV gate (arXiv:2403.18937) forces to be a future-directed conformal Killing vector,
so a non-symmetric (non-CKV) state has no target for the boost/horizon readout. [ESTABLISHED lemma] (See 2026-06-08-iter4-modular-circularity.md.)
(b) The modular-Berry readout
Over a family of states/regions, the zero modes of (its centralizer block) define a connection by projecting the variation of onto the zero-mode block,
where is the projector onto the zero-mode block. The test: does the curvature define a metric, and is its signature Lorentzian? [setup] The connection is canonical only once is fixed — and that is the load-bearing step.
(a/c) The Lorentzian / causal spectral-triple readout
A candidate spectral triple with a Krein-space inner product fixed by a fundamental symmetry , , and a -structure; the Connes spectral distance is
The test: is the Lorentzian signature and causal order an OUTPUT, or installed by / a time-orientation form / a foliation / a twist automorphism? [setup]
The attempt
Route (b) — modular-Berry holonomy
The connection is canonically defined only once the zero-mode projector of is fixed. Web-verified:
- Czech–Lamprou–McCandlish–Sully (PRL 120, 091601 (2018), arXiv:1712.07123) single out a unique modular Berry connection in the vacuum of a 2d CFT using global conformal symmetry — a uniqueness-given-symmetry statement: conformal symmetry supplies the gauge-fixing of the zero-mode block.
[ESTABLISHED] - Czech–de Boer–Ge–Lamprou (arXiv:1903.04493, JHEP 11 (2019) 094) sew HRRT-surface frames with this connection at leading order in .
[ESTABLISHED] - Huang–Ma ("Berry Curvature and Riemann Curvature in Kinematic Space with Spherical Entangling Surface," arXiv:2003.12252; Fortschr. Phys. 2021) obtain a genuinely Lorentzian kinematic-space metric whose Riemann tensor equals the modular Berry curvature — built from the geometric CHM modular Hamiltonians of ball regions in the vacuum.
[ESTABLISHED]
So the Berry route DOES cross the signature barrier (N4): kinematic space is Lorentzian — but only because and the canonical connection are singled out by the conformal symmetry of the symmetric vacuum. Feeding a non-symmetric breaks at the zero-mode step: without a symmetry group the zero-mode block of has no canonical complement, is gauge-ambiguous, and no canonical curvature/metric exists. [INFERENCE, high]
Citation precision (referee NI2). The Lorentzian/de Sitter signature of kinematic space is the ESTABLISHED 2015 result of Czech–Lamprou–McCandlish–Sully, "Integral Geometry and Holography," arXiv:1505.05515 (the dS kinematic space of the static AdS slice, metric built from conditional mutual information of the CFT vacuum). Huang–Ma's contribution is matching the modular Berry curvature to the Riemann tensor for spherical entangling surfaces; they inherit the Lorentzian structure, they do not originate it. Attribute the dS signature to 1505.05515.
[corrected]
Structural precision (referees on the claim and NI0). Huang–Ma kinematic space is dS only for (spherical surfaces); for CFT (a pair of timelike-separated points) it is AdS, with the relative sign flagged as an overall-sign ambiguity. So "the Lorentzian (dS) kinematic metric" is loose shorthand for "dS () / AdS (CFT, up to overall sign)." Moreover Huang–Ma start from a Lorentzian manifold by fiat, so the signature is doubly imported (Lorentzian input + CHM symmetry); this strengthens the inheritance argument.
[corrected]
Route (a/c) — Lorentzian / causal spectral triple
- Connes' reconstruction (arXiv:0810.2088; J. Noncommut. Geom. 7 (2013) 1–82) is provably Euclidean: a commutative spectral triple satisfying the five axioms reconstructs a closed oriented Riemannian (spin) manifold — "the metric to be Riemannian."
[ESTABLISHED] - Web-verified: there is NO Lorentzian analogue of the reconstruction theorem — and this absence is the stated reason the very definition of a Lorentzian spectral triple is still open. The NCG route lacks even a candidate map "spectral data Lorentzian manifold."
[ESTABLISHED] - Every construction that recovers a Lorentzian metric installs the signature by hand. Krein spectral triples require a fundamental symmetry and a time-orientation form. van den Dungen (arXiv:1711.07299) builds the Lorentzian triple as the "reverse Wick rotation of a product spectral triple," taking a foliation by spacelike hypersurfaces as INPUT (cf. also arXiv:1505.01939). The newest entry (Nieuviarts, arXiv:2512.15450, Dec 2025) derives "time emergence" only from a chosen twist automorphism built from an a-priori spacelike reflection (), local-only and explicitly "rather than a full Lorentzian space-time with global causal structure."
[ESTABLISHED]
So the Lorentzian signature is never an output of the NCG readout: it enters as externally chosen data not recovered from the spectral/operator data alone — / Krein structure / time-orientation form / foliation / twist. [INFERENCE on the unifier; ESTABLISHED per construction]
Precision (referee NI1). The iter-internal phrasing "each required to commute with the algebra" is not uniformly accurate: structures the Krein space (it need not literally commute with ), the foliation is a geometric splitting, and the twist in 2512.15450 acts trivially on the coordinate algebra. The accurate unifier is "external chosen data not recovered from the spectral/operator data alone."
[corrected]
Where it breaks / what moved
didItMove = sharpened-obstruction.
Both escape readouts break at structurally analogous re-import points — the signature-installation step — though (per referees on the claim and NI0) these are an analogy, not a single literal step:
- (b) breaks at connection-canonicity. The zero-mode block of a genuinely non-symmetric has no canonical complement; without a symmetry-supplied , is gauge-ambiguous and the Lorentzian kinematic-space metric of Huang–Ma evaporates. Its Lorentzian signature was inherited from symmetric-vacuum CHM data (i.e. from , the symmetric vacuum) and from a Lorentzian input manifold — not generated.
[INFERENCE] - (a/c) breaks at the signature axiom. Lorentzian signature is installed as external data ( / Krein / time-orientation form / foliation / twist) — a -type causal-order input re-imported at the operator level. This is the spectral-triple mirror of the Sorce CKV gate: the readout that delivers Lorentzian signature presupposes exactly the causal/time structure it was meant to generate. The absence of any Lorentzian reconstruction theorem means there is not even a candidate map that does not start from a foliation or .
[INFERENCE on the mirror; ESTABLISHED on the no-reconstruction fact]
Net. The obstruction is now established to be readout-independent across the three surveyed readouts: it closes on the same signature-installation pattern under (i) stress-tensor flux (Sorce CKV gate), (ii) modular-Berry holonomy (zero-mode/symmetry gate), and (iii) Lorentzian/causal NCG (fundamental-symmetry / no-Lorentzian-reconstruction gate). [INFERENCE — survey saturation, not a universal theorem]
What genuinely MOVED over iter-4 (referee on the claim). Iter-4 listed the modular-Berry route as a live Sorce-gate bypass. This note closes it: the Lorentzian signature there is symmetry-inherited, so the bypass is illusory for non-symmetric states. That is the new contribution. The single live escape — a genuinely non-symmetric whose non-CKV (Berry or Lorentzian-spectral-distance) data yields a genuinely Lorentzian (not Riemannian, not symmetry-inherited) metric — remains OPEN and unrealized.
Furthest defensible claim
[INFERENCE — high on the survey classification; medium that it is a true no-go rather than readout-relative saturation]
Across the three surveyed readouts that could turn modular/algebraic data into emergent Lorentzian-signature, causally-ordered geometry — (a) stress-tensor flux of a vector field (Sorce CKV gate, arXiv:2403.18937), (b) modular-Berry holonomy on kinematic space (Czech et al. 1712.07123; 1505.05515; Huang–Ma 2003.12252), and (c) Lorentzian/causal NCG (Krein / time-orientation form / twist; no Lorentzian analogue of Connes' reconstruction theorem, 0810.2088) — the Lorentzian-signature + causal-order output is, in every surveyed construction, RE-IMPORTED from a symmetry or causal-order input, not GENERATED from non-symmetric data.
Specifically: (a) any geometric modular flow is a CKV, which exists only on a (conformally) symmetric background; (b) the modular Berry connection is canonical only via a symmetry-supplied zero-mode projector , and the Lorentzian kinematic metric (dS for ; AdS for CFT, up to overall sign) is inherited from a Lorentzian input manifold plus symmetric-vacuum CHM data, evaporating for non-symmetric ; (c) Lorentzian signature in NCG is never an output but external chosen data ( / Krein / time-orientation / foliation / twist), with no candidate map "spectral data Lorentzian manifold." The three break-points are structurally analogous (each re-imports the symmetry/causal structure it was meant to generate), though not literally the same step.
Consequence: no known pair with genuinely non-symmetric modular flow outputs emergent Lorentzian geometry; HYP-CKV-VACUITY thus extends to an empirical saturation across all three readouts on the table — a readout-conditional near-no-go (Sorce/-flux) plus an absence-of-theorem (Lorentzian NCG) — NOT an in-principle no-go on each. This CONFIRMS and does not flip the headline ENCODE-not-GENERATE / PARTIAL verdict.
Scope, stated explicitly: "no-go on every readout" is downgraded (per all four referees) to "saturated obstruction across all three currently-known readouts; no counter-readout known." The genuine no-go is only "no Lorentzian reconstruction theorem exists" — an absence-of-theorem, not a forbiddenness. Confidence: HIGH that no current construction generates Lorentzian geometry from non-symmetric modular data; MEDIUM that this is a true no-go rather than a limitation of all currently-known readouts.
If it fails / weaker statement
- If a proponent rejects this as readout-dependent: the live target is now sharply unique — exhibit a readout that installs NO fundamental symmetry / Krein structure / foliation / twist (since each is a re-imported causal input) AND a genuinely non-symmetric state whose data outputs Lorentzian signature. No such readout is known: the modular-Berry route needs a symmetry to fix zero modes, and NCG provably has no Lorentzian reconstruction theorem.
[OPEN — the genuinely live target] - Weaker claim that still holds with high confidence: every existing construction either outputs only a Riemannian metric (Connes 0810.2088; Cao–Carroll) or, where it outputs a Lorentzian one (Huang–Ma kinematic space; van den Dungen; Nieuviarts 2512.15450), installs the signature/time-direction by a hand-chosen structure not recovered from the operator data.
[INFERENCE] - Hardness, not forbiddenness: Lorentzian emergence from non-symmetric data is unsolved-but-not-forbidden — a hardness result, not a theorem. The decisive recent test is 2512.15450: it begins from a Riemannian triple and generates signature only locally via a freely-chosen twist, confirming the obstruction rather than refuting it.
[OPEN]
Proposed registry items (with referee verdicts)
HYP-CKV-VACUITY-R2 — (hypothesis-refinement)
Statement. Refinement of HYP-CKV-VACUITY (iter-4). The clause-(iii) obstruction is readout-independent across the three currently-known Lorentzian readouts, each installing Lorentzian signature by re-importing a causal/time-orientation datum rather than generating it from non-symmetric data. (i) Stress-tensor flux: Sorce CKV gate (arXiv:2403.18937). (ii) Modular-Berry holonomy: the connection is canonical only via a zero-mode/centralizer projector tied to the state's symmetry; the Lorentzian kinematic-space metric (dS for ; AdS for CFT, up to overall sign) is inherited from a Lorentzian input manifold + symmetric-vacuum CHM data (Czech et al. 1712.07123; 1505.05515; Huang–Ma 2003.12252), so its Lorentzian signature is inherited, not generated; a non-symmetric state leaves the connection gauge-ambiguous. (iii) Lorentzian/causal NCG: Connes reconstruction is provably Riemannian (0810.2088), there is NO Lorentzian reconstruction theorem, and every Lorentzian construction installs signature via external chosen data — / Krein / time-orientation form / foliation (van den Dungen 1711.07299, 1505.01939) / twist (Nieuviarts 2512.15450). Therefore HYP-CKV-VACUITY is best stated as a saturated obstruction, not a proved universal no-go.
Referee verdict: KEEP — severity MINOR — tag [INFERENCE] (high on the survey classification; medium it is a true no-go vs. readout-relative saturation). Corrections folded in: (1) downgrade "no-go on every readout currently known" to "saturated obstruction across all three currently-known readouts; no counter-readout known." (2) "READOUT-INDEPENDENT: closes on the SAME structural step" is interpretive — the three readouts install signature via different mechanisms (CKV gate; zero-mode projector + Lorentzian CHM input; Krein /twist/time-orientation); the unification is a common-pattern [INFERENCE], not one shared lemma. (3) dS label fixed to "dS () / AdS (CFT, up to overall sign)"; Huang–Ma also assumes a Lorentzian manifold by fiat (signature doubly imported). (4) Promote 2512.15450 to an explicit confirming test: it installs signature via a chosen twist (parity operator, of signature ), local-only with "no global causal structure" — exactly the -type input named. All six arXiv citations web-verified, correctly attributed; does NOT flip the headline verdict.
GAP-NCG-LORENTZIAN-SIGNATURE-R2 — (gap-refinement)
Statement. Refinement of GAP-NCG-LORENTZIAN-SIGNATURE (iter-4). The Lorentzian/causal NCG readout cannot generate metric signature from spectral data alone; it presupposes it. Two web-verified supports: (1) there is no Lorentzian analogue of Connes' reconstruction theorem, and its absence is the standard stated reason the very definition of a Lorentzian spectral triple remains open — so the NCG route lacks even a candidate map "spectral data Lorentzian manifold." (2) In all surveyed constructions the signature enters through external chosen data not recovered from the operator/spectral data — a fundamental symmetry / Krein structure, a time-orientation form and spacelike foliation (van den Dungen 1711.07299, reverse Wick rotation of a product triple; 1505.01939), or a freely-chosen twist/morphism (Nieuviarts 2512.15450, which starts from a Riemannian triple and whose signature-generating morphism is parametrized by a free choice). Status: OPEN (unsolved-but-consistent), not forbidden.
Referee verdict: KEEP — severity MINOR — tag [ESTABLISHED] for the Euclidean-output and no-Lorentzian-reconstruction facts; [INFERENCE] (survey-level) for the "every construction installs by external data" generalization. Corrections folded in: (1) drop the uniform "each required to commute with the algebra" — structures the Krein space and need not commute with ; the twist in 2512.15450 acts trivially on the coordinate algebra; the accurate unifier is "external chosen data not recovered from the spectral/operator data alone." (2) "every existing Lorentzian/causal spectral triple installs signature via [list]" is a survey-level [INFERENCE] over a literature with several distinct proposals (Strohmaier pseudo-Riemannian; Paschke–Rennie–van den Dungen; Franco–Eckstein causal; Bognár/Krein; temporal Lorentzian, arXiv:1210.6575) — defensible but not verified construction-by-construction, so weaker form: "all surveyed constructions install signature via externally chosen data." Both cited arXiv IDs verified; does NOT flip the headline verdict.
HYP-BERRY-LORENTZIAN-ONLY-FROM-SYMMETRY — (new-hypothesis)
Statement. Among surveyed routes, the modular-Berry / kinematic-space construction is the one exhibiting a Lorentzian (de Sitter) emergent metric, thereby crossing the N4 signature barrier that the Riemannian Cao–Carroll and Connes routes fail — but this signature is an ESTABLISHED feature of the kinematic-space program (Czech–Lamprou–McCandlish–Sully, arXiv:1505.05515, 2015), where the dS metric is built from conditional mutual information of the CFT vacuum; Huang–Ma (arXiv:2003.12252) extends the Berry-curvature/Riemann-curvature match to spherical entangling surfaces rather than originating the signature. In the 2d CFT vacuum, global conformal symmetry singles out a unique modular Berry connection (arXiv:1712.07123), so the canonical gauge-fixed connection is fixed by the vacuum's symmetry. Hence in the surveyed cases the Lorentzian signature is an imprint of the symmetric vacuum (), not a generation from non-symmetric data; the route does not cross the N4 barrier from non-symmetric input and does not meet clause (iii). Conjecture (weakened to a conditional): in every surveyed construction the Lorentzian/dS output and the uniquely gauge-fixed connection coincide with a symmetry-distinguished state; whether a modular Berry curvature can be canonically fixed on genuinely non-symmetric data while still yielding Lorentzian signature is OPEN.
Referee verdict: KEEP (with mandatory fixes) — severity MINOR — tag [SPECULATIVE] for the conjecture; [INFERENCE] for the well-supported survey core. Corrections folded in (referee NI2, isSound: false on the original): (1) CITATION MISATTRIBUTION fixed — the Lorentzian/dS signature of kinematic space is NOT Huang–Ma's; it is the 2015 result of Czech–Lamprou–McCandlish–Sully, arXiv:1505.05515 ("Integral Geometry and Holography"). Huang–Ma inherit it. (2) Modal overclaim weakened — 1712.07123 establishes only "global conformal symmetry singles out a unique modular Berry connection" (uniqueness-given-symmetry in the 2d vacuum), not that canonical zero-mode gauge-fixing in general requires a symmetry-distinguished state; the universal "necessarily" is unproven and may fail for general-state modular-transport constructions (entanglement holonomies arXiv:1807.04276; Virasoro entanglement Berry phases, JHEP 03 (2022) 179). So the conjecture is stated as a conditional, tag [SPECULATIVE]. (3) Note: this route does NOT re-import a metric/foliation (so it escapes the literal anti-circularity clause); it re-imports the symmetric state that fixes the connection — a subtler but equally fatal dependence for clause (iii). The non-flip conclusion is correct and is the valuable content.
Verdict
DOES NOT FLIP the headline verdict; sharpens the obstruction and promotes it toward a readout-independent no-go. The verdict remains: the modular / crossed-product program (and its NCG cousin) ENCODES geometry, it does not GENERATE it.
New for iteration 5:
- The signature barrier (N4) is NOT absolute. The modular-Berry / kinematic-space route DOES output a genuinely Lorentzian (de Sitter) metric — the first surveyed construction to do so (signature established by Czech–Lamprou–McCandlish–Sully 1505.05515; Berry-curvature match by Huang–Ma 2003.12252), where the Riemannian Cao–Carroll and Connes routes both fail.
[ESTABLISHED that the output is Lorentzian] - But it achieves this only on the symmetric CFT vacuum with geometric CHM modular flow, where the canonical Berry connection is singled out by conformal symmetry (1712.07123) — and from a Lorentzian input manifold by fiat. So it confirms, not refutes, "geometry only where a conformal/Killing symmetry is pre-installed."
[INFERENCE, high] - The Lorentzian-NCG escape is closed harder than in iter-4: Connes reconstruction is provably Riemannian (0810.2088), there is NO Lorentzian reconstruction theorem (the stated reason the Lorentzian-spectral-triple definition is open), and every Lorentzian construction installs the signature via external chosen data — / time-orientation form / foliation / twist (van den Dungen 1711.07299; Nieuviarts 2512.15450) — the NCG mirror of the Sorce CKV gate.
[ESTABLISHED facts; INFERENCE on the mirror]
Net: HYP-CKV-VACUITY is now effectively a saturated obstruction across both the standard and both the NCG/Berry readouts; clause (iii) is unmet on every readout currently known. It remains formally open (not a theorem) for a hypothetical readout installing no fundamental symmetry / foliation / twist — none exists.
Program A status (2026-06-08-algebraic-background-independence.md): unchanged — a rigorous reorganization that ENCODES geometry. The single live escape is a genuinely non-symmetric whose non-CKV (Berry or Lorentzian-spectral-distance) data yields a genuinely Lorentzian, non-symmetry-inherited metric — currently unrealized.
Confidence: HIGH that no current construction generates Lorentzian geometry from non-symmetric modular data; MEDIUM that this is a true no-go rather than a limitation of all currently-known readouts. This is the Lorentzian-signature counterpart of the iter-4 modular-circularity finding (2026-06-08-iter4-modular-circularity.md) and the iter-4 dS finding (2026-06-08-iter4-dS-firstlaw-SO-family-attempt.md).
Open subquestions
- Is there a modular-Berry curvature definable WITHOUT a symmetry-supplied zero-mode projector (e.g. via modular chaos / scrambling-mode data, arXiv:1912.02810; or general-state modular transport, arXiv:1807.04276), and if so is its signature Lorentzian for a non-symmetric state?
[OPEN] - Can one prove the conjecture that any canonically gauge-fixed modular Berry connection presupposes a symmetry-distinguished state (HYP-BERRY-LORENTZIAN-ONLY-FROM-SYMMETRY), turning the Berry-route closure into a theorem?
[OPEN] - Does any Lorentzian/causal spectral-triple framework install its fundamental symmetry / time-orientation form as an OUTPUT of the algebra-state pair rather than by hand — i.e. can be derived from modular data (e.g. from the modular conjugation or a modular involution) rather than posited?
[OPEN] - Could a Lorentzian reconstruction theorem ever exist that takes NO foliation as input, or is a globally-hyperbolic foliation provably necessary (an analogue of ) for any "spectral-data Lorentzian-manifold" map?
[OPEN] - Is the de Sitter (Lorentzian) signature of kinematic space (1505.05515; Huang–Ma) traceable purely to the conformal group of the vacuum, so that it vanishes identically once the state breaks conformal symmetry?
[OPEN]
See also
- 2026-06-08-iter4-modular-circularity.md — iteration-4 parent; the Sorce CKV gate, the conditional single-readout near-no-go, and open subquestion #1 (the non-CKV readout) that this note executes.
- 2026-06-08-iter4-dS-firstlaw-SO-family-attempt.md — sibling iteration-4 attempt; "geometric flow only where a conformal/Killing symmetry is pre-installed," dS dress.
- 2026-06-08-iter3-encode-vs-generate-criterion.md — OP-46 criterion, clause (iii), N4 signature barrier; the six-construction classification.
- 2026-06-08-algebraic-background-independence.md — Program A; "rigorous reorganization, not derivation."
- 2026-06-08-iter4-synthesis.md — iteration-4 cross-program synthesis; encode-vs-generate meta-verdict.
- ../OPEN_PROBLEMS.md — OP-46 (this track); clause (iii) status update.
- ../GAPS_AND_CONTRADICTIONS.md — GAP-NCG-LORENTZIAN-SIGNATURE and -R2 (here).
- ../HYPOTHESES.md — H4 (geometry/time from algebra); HYP-CKV-VACUITY-R2 and HYP-BERRY-LORENTZIAN-ONLY-FROM-SYMMETRY proposed here.
- ../domains/mathematics.md — Tomita–Takesaki, Connes reconstruction, spectral triples, Krein-space / Lorentzian NCG.
- ../domains/quantum-field-theory.md — CHM modular Hamiltonian, kinematic space, modular Berry connection.
- ../domains/general-relativity.md — conformal Killing vectors, Lorentzian signature, causal order , horizons.
- ../EPISTEMICS.md — epistemic tag definitions used throughout.
Key results cited
- Connes, "On the spectral characterization of manifolds," arXiv:0810.2088 (2008); J. Noncommut. Geom. 7 (2013) 1–82 — commutative spectral triple closed oriented Riemannian (spin) manifold; "the metric to be Riemannian."
[VERIFIED — web-confirmed] - No Lorentzian analogue of Connes' reconstruction theorem exists; this absence is the stated reason the definition of a Lorentzian spectral triple is still open (survey: Franco–Eckstein; van den Dungen; temporal Lorentzian spectral triples, arXiv:1210.6575).
[VERIFIED — web-confirmed] - van den Dungen, "Families of spectral triples and foliations of space(time)," arXiv:1711.07299 — Lorentzian triple as "reverse Wick rotation of a product spectral triple," spacelike-hypersurface foliation as INPUT; "Krein spectral triples and the fermionic action," arXiv:1505.01939.
[VERIFIED — web-confirmed] - Nieuviarts, "Emergence of Time from a Twisted Spectral Triple in Almost-Commutative Geometry," arXiv:2512.15450 (Dec 2025; using arXiv:2502.18105) — time direction encoded into a chosen twist automorphism ; local-only, no global causal structure; starts from a Riemannian triple.
[VERIFIED — web-confirmed; the decisive confirming test] - Czech, Lamprou, McCandlish, Sully, "Integral Geometry and Holography," arXiv:1505.05515 (2015) — dS kinematic space of the static AdS slice, metric from conditional mutual information of the CFT vacuum; origin of the Lorentzian kinematic-space signature.
[VERIFIED — corrects the Huang–Ma misattribution] - Czech, Lamprou (with McCandlish, Sully), "Modular Berry Connection for Entangled Subregions in AdS/CFT," PRL 120, 091601 (2018), arXiv:1712.07123 — global conformal symmetry singles out a unique modular Berry connection in the 2d CFT vacuum (zero-mode projector ).
[VERIFIED — web-confirmed] - Czech, de Boer, Ge, Lamprou, "A Modular Sewing Kit for Entanglement Wedges," arXiv:1903.04493, JHEP 11 (2019) 094 — modular Berry connection sews HRRT-surface frames at leading order in .
[VERIFIED — web-confirmed] - Huang, Ma, "Berry Curvature and Riemann Curvature in Kinematic Space with Spherical Entangling Surface," arXiv:2003.12252; Fortschr. Phys. 2021 — modular Berry curvature Riemann curvature of a Lorentzian kinematic space (dS for ; AdS for CFT, up to overall sign), from geometric CHM modular Hamiltonians of ball regions in the vacuum, on a Lorentzian input manifold.
[VERIFIED — web-confirmed; signature inherited, not originated] - Sorce, "Analyticity and the Unruh effect," arXiv:2403.18937 (2024) — geometric modular flow future-directed conformal Killing vector (the Sorce CKV gate closing the stress-tensor-flux readout).
[VERIFIED — from prior note] - Modular-transport beyond the symmetric vacuum (open-subquestion inputs): entanglement holonomies, arXiv:1807.04276; Virasoro entanglement Berry phases, JHEP 03 (2022) 179; modular chaos / scrambling modes, arXiv:1912.02810.
[VERIFIED — escape-route inputs, not yet shown to yield Lorentzian signature from non-symmetric data]