Energy-Flow Cosmology (EFC) — Stage-IV Data Roadmap

Pitch Ledger White Paper Roadmap Gaps External Predictions Atlas Changelog

Morten Magnusson · Symbiose Research, Sandnes, Norway · ORCID: 0009-0002-4860-5095 · April 2026 · CC-BY-4.0

What is Energy-Flow Cosmology? A 60-second version.

Today's standard picture of the universe says 95% of it is made of two invisible ingredients — dark matter and dark energy — neither ever detected in a laboratory. EFC proposes a simpler alternative: gravity adjusts itself where disorder (entropy) is still building up, and behaves like ordinary Einstein gravity everywhere else. One mechanism, two numbers, no invisible particles required.

The difference is ontological, not parametric. ΛCDM treats spacetime as a fixed stage with dark matter + dark energy as ingredients. EFC treats energy and entropy as primary — spacetime, gravity, and time itself (an index over irreversible Grid transitions) emerge from them. The "dark" sector is not a set of missing particles; it is a consequence of how a single-regime observer reads cross-regime physics. See the Pitch for the full side-by-side.

This roadmap lists the next-generation surveys that will decide whether EFC survives or falls. Each row is a kill criterion frozen before the relevant data arrives, so no result can be back-fitted. Ledger for the 121 tests registered (103 active, 93 survived, 10 falsified, 18 in pipeline).

One sentence: This roadmap maps every major Stage-IV data release (2026–2031+) to the specific EFC prediction, observable, regime, and kill criterion it will test — so that no result arrives without a pre-registered expectation.


0. Purpose and Governance

The Ledger documents what has been tested. The White Paper documents what EFC predicts. This roadmap documents when and how those predictions will be confronted with data. The Background No-Go Theorem establishes why all predictions are in the perturbation sector, not the background.

Governance rule: All entries in this roadmap are frozen at the time of publication. No post-hoc addition of tests after data release is permitted. New tests may be added to future versions of this roadmap before the relevant data becomes public. Additions are versioned and timestamped.


0.1 Notation and Conventions

Symbol Definition Domain
μ(k,z) Effective gravitational coupling (Poisson equation modifier). μ = 1 is GR. EFC perturbation sector: μ ≈ 0.94. Perturbations (L1–L2)
Σ(k,z) Lensing potential modifier. Σ = 1 is GR. EFC: Σ ≈ 1.05. Lensing (L1–L2)
η Gravitational slip: η ≡ Φ/Ψ. η = 1 is GR. EFC: η ≈ 1.10. Perturbations (L1)
β Entropy-gradient coupling strength. β ≈ 0.16 from SPARC (galactic); βcosm ≈ 1.0 (cosmological). All regimes
S(a) Entropy field, S ∈ [0, 1]. Fundamental scalar in EFC. All regimes
T(a) Regime transition function. Controls when background coupling activates. Background (L0–L2)
αL2 Integrated growth-sector coupling amplitude. Sealed: α = −0.689 (v1), −0.702 (v2). Growth (L1–L2)
Θ(ρ) Density saturation function. Θ → 0 at high density (Solar System); Θ → 1 at low density (cosmological). Screening (L2–L3)
k SPARC screening exponent: k = 0.415 ± 0.029 (174 galaxies). Galactic (L2)
ξ, ηreg Regime coordinates: ξ ≡ |∇Φ|/a₀ (gradient); ηreg ≡ μΛΦ/|∇²Φ| (screening). See Ledger. All regimes
L0–L3 Regime levels: L0 = early-universe linear; L1 = late-time linear; L2 = non-linear; L3 = strong-field. Classification

Statistical conventions

All significance levels (σ) in this document are frequentist, computed as √Δχ² for nested models or as the equivalent Gaussian significance of a p-value for non-nested comparisons. Unless stated otherwise, tests are two-sided except where a directional prediction is specified (e.g., μ < 1, α < 0), in which case one-sided significance is reported and explicitly marked. Model comparison uses Δχ² and ΔAIC as primary metrics; Bayesian evidence ratios (ln B) are reported where available but are not used as primary decision criteria due to prior sensitivity.


1. Survey Timeline Overview

Survey / Instrument Data Release Expected Date Key Content for EFC
Phase I — 2026 (Current)
DESI DR2 (cosmology chains) 2025 Oct (released) BAO (14M galaxies+QSOs, 3 yr); w₀waCDM constraints
DESI DR2 (full spectra + redshifts) 2026 H2 Full-shape P(k); RSD fσ8 multi-epoch; Lyα forest
Euclid Q2 (Quick Release 2) 2026 Jun 24 Galactic bulge survey; calibration; cross-match with Roman precursor
Euclid DR1 2026 Oct 21 ~2100 deg² weak lensing; photometric redshifts; cosmic shear; galaxy clustering; first dark energy constraints
Rubin/LSST DP2 (Data Preview 2) 2026 Jul–Sep LSSTCam commissioning data; deep drilling fields; transient alerts
Rubin/LSST Alert stream (live) 2026 Feb (active) Real-time transients; void identification precursors
Planck + ACT DR6 + SPT-3G CMB lensing 2026 baseline 2026 (available) S8CMB = 0.836 ± 0.012 (Qu et al. 2026, SNR = 61)
JWST Cycle 4 observations 2026 (ongoing) Cluster κ maps (Bullet, Abell 2146); high-z galaxy abundances; void lensing
Phase II — 2027–2028
DESI DR3 (full 5-year) ~2027–2028 Full-shape + RSD joint; neutrino mass; fσ8 trajectory z = 0.02–1.5
Euclid DR2 ~2028 First 3 years; ~7000 deg²; tomographic cosmic shear; galaxy clustering; gravitational slip η; EG statistic
Rubin/LSST DR1 ~2028 Jun First full year; 18000 deg² southern sky; shear catalogue; void catalogues; cluster abundance N(M,z)
Roman Early observations ~2027–2028 High-z SNe Ia; complementary weak lensing; BAO independent check
KiDS Legacy (final) ~2027 Resolves DES vs KiDS S8 bifurcation; definitive Stage-III reference
SPT-3G / ACT DR7 Next-gen CMB lensing ~2027–2028 Improved Cφφ; AL degeneracy resolution; independent η constraint
Phase III — 2029–2031+
Euclid DR3 (final) ~2030–2031 Full 14000 deg²; definitive w₀, wa; μ–Σ joint; η to 1% precision
Rubin/LSST DR2–DR5 2029–2034 Cumulative depth; small-scale non-linear structure; void ISW stacking
DESI Final legacy ~2029 40M redshifts; definitive RSD trajectory; BAO anisotropic split
CMB-S4 → Simons Observatory SO science data / LiteBIRD (2032+) SO: ~2026–2028; LiteBIRD: 2032+ CMB-S4 cancelled July 2025. SO LAT operational (first light Feb 2025): CMB lensing, E/B polarisation, ISW. LiteBIRD: primordial B-modes, full-sky τ.
Einstein Telescope Design / early 2030s Standard sirens: propagation-sector test (GW vs EM distances)
SKA Early science ~2029–2030 HI intensity mapping; independent BAO; cosmic dipole test

2. Prediction × Data Matrix

Each row maps a specific EFC prediction to the dataset that will test it, the observable, the quantitative pass/fail criterion, and the pipeline readiness status.

2.1 Kill Criteria (KC1–KC5) — Stage-IV Falsification Tests

Thresholds frozen before data release. No post-hoc adjustment permissible. Defined in White Paper.

KC Criterion Trigger Primary Dataset Expected Date Pipeline Status
KC1 Growth suppression absent L2| < 0.1 at 3σ DESI DR3 full-shape + RSD ~2027–2028 PIPELINE NEEDED Full-shape likelihood
KC2 Wrong fσ8 trajectory |zcross − 2.042| > 3σ DESI DR3 RSD multi-epoch ~2027–2028 SEALED Freeze v1 hash: 7a850cfa...
KC3 S8 converges to ΛCDM S8 = S8,ΛCDM ± 0.005 Euclid DR1 cosmic shear + CMB lensing 2026 2026 Oct P3 PASS on DES Y6 (0.3σ); Euclid will arbitrate
KC4 Perturbation-sector signature absent μ > 1 detected OR Σeff(z) monotonic OR EGobs/EGGR = 1.00 ± 0.01 (all at >3σ) Euclid DR1 tomographic shear; SO × Euclid DR2 EG 2026 Oct (DR1) — 2028 (DR2) SEALED Perturbation sector (32037990: μ < 1 structurally robust, Σeff(z) crossover at z ≈ 0.44), EG pre-registration (32023788), Rubin DP2 cosmic shear (32013738), μ–Σ eigenmode (31990194)
KC5 No dynamical dark energy |w₀ + 1| < 0.02 (Euclid) Euclid DR1/DR2 + DESI DR3 joint 2026–2028 DESI DR2 shows 2.3σ preference for w₀waCDM; monitoring

2.2 Sealed Blind Predictions

PredictionValueHashTest DatasetExpected Date
SEALED v1 αL2−0.6897a850cfa...DESI DR3 fσ8 + BAO joint~2027–2028
SEALED v18 crossoverz = 2.0427a850cfa...DESI DR3 Lyα + high-z RSD~2027–2028
SEALED v2 αL2−0.702dbccda15...DESI DR3 fσ8 + BAO joint~2027–2028
SEALED v1 DH/rd(z=1.0)EFC: 16.527 vs ΛCDM: 17.466 (3.1σ)7a850cfa...DESI DR3 BAO anisotropic~2027–2028
SEALED v1 DH/rd(z=0.7)EFC: 19.797 vs ΛCDM: 20.719 (2.3σ)7a850cfa...DESI DR3 BAO anisotropic~2027–2028
SEALED v18(z=0.7)EFC: 0.430 vs ΛCDM: 0.449 (2.0σ)7a850cfa...DESI DR3 RSD~2027–2028
↑ Formal DOI publication of all three sealed predictions: 32013156 (Magnusson 2026, NUTS sampler, T1 pre-registered)

2.3 Action-Level Falsification Conditions (FA1–FA6)

Defined in the EFC Relativistic Action (31876324). These govern the perturbation sector and supersede phenomenological F7.

FAConditionPrimary DatasetExpected DateNotes
FA1cT ≠ c at any redshiftLIGO/Virgo/KAGRA O5; Einstein Telescope2027+ / 2030sCurrently PASS (GW170817)
FA2μ > 1 in linear cosmological regimeEuclid DR1/DR2 tomographic growth2026–2028EFC predicts μ ≈ 0.94 in survival valley
FA3Σ < 1 in perturbation sectorEuclid DR2 cosmic shear C~2028EFC predicts Σ ≈ 1.05
FA4η = 1 to sub-percent precisionEuclid DR2/DR3 (EG + lensing×RSD)2028–2031EFC predicts η ≈ 1.10
FA5No GR screening in high-densitySolar System (Cassini, LLR) — already constrainedOngoingCurrently PASS; future: LISA Pathfinder legacy
FA6Ghost / tachyon instability detectedTheoretical / numerical (ADM Hamiltonian)N/ACurrently PASS at 2nd order; full non-linear pending

2.4 Standing Falsification Conditions (F1–F6)

FConditionPrimary DatasetExpected DateEFC Prediction
F1AISW = 1.00 ± 0.02 (tracer-independent)DESI DR2/DR3 × Planck CTg2026–2028EFC: AISW ≈ 0.89 ± 0.03
F2No RSD deviation from ΛCDM across z = 0.02–1.5DESI DR3 multi-epoch RSD~2027–2028EFC: monotonic suppression via β·T(a)
F3Cluster lensing asymmetry absent (Asig = 0)JWST κ maps (Bullet, Abell 2146)2026–2027EFC: directional residual from entropy coupling
F4Full-shape P(k) inconsistent with background-only growthDESI DR3 full-shape likelihood~2027–2028EFC: background channel primary; scale-dependent if μ(k,z) active
F5Graph-AQUAL fails rotation curve diversitySPARC + MaNGA joint likelihood (ongoing)IncrementalEFC: regime-dependent EBE with k = 0.415
F6Λ-locked screening produces growth instabilityNumerical (N-body + Λ-lock)IncrementalEFC: stable under Λ-lock (CGS pass)

2.5 Specific Observational Predictions (Awaiting Data)

PredictionEFC Value / ExpectationPrimary DatasetExpected DateRegimeReference
Void ISW sign-flipCold→hot for δ ≲ −0.8; turnover near δ ≈ −0.7Rubin DR1 void catalogue × Planck/ACT CMB~2028L1–L231942677
Cosmic dipole excess~2% entropy gradient → directional GeffRubin DR1 + SKA early science number counts2028–2030L131942731
Regime transition μ<1 ↔ μ>1Cluster-scale μ ≈ 1.1, Σ ≈ 1.2; no μ>1 in linearEuclid DR2 cluster lensing + Rubin DR1~2028L2–L331941543
Dynamical dark energy w(a) ≠ −1w(a) = −β(S)·a; KC5 testEuclid DR1/DR2 + DESI DR2/DR3 BAO joint2026–2028L1–L2WP Part 4
Cross-scale amplification βcosmgal ≈ 6.25Susceptibility T(S) links SPARC → cosmic shearEuclid DR2 tomographic shear × SPARC Phase 3~2028L2WP Part 4
AL degeneracy resolutionPhysical Σ>1 distinguishable from phenomenological AL>1Euclid DR2 galaxy lensing + CMB lensing + fσ8~2028L0–L131368433
Lensing-to-CMB S8 ratio (P3 replication)0.95 ± 0.03 (pre-registered); DES Y6 PASS at 0.3σEuclid DR1 cosmic shear / CMB lensing 20262026 OctL1–L231951992
Standard sirens (GW vs EM distance)Propagation-sector β-split testEinstein Telescope / LISA2030sPROP31305421
SMBH thermostat: AGN decline drives S(z) sigmoidS(z) transition at z ~ 1 tracks AGN luminosity densityJWST + eROSITA AGN catalogue2027–2029L231942734
Cluster abundance N(M,z)Mass function evolution discriminates EFC vs ΛCDMeROSITA + Euclid DR2 + Rubin DR1~2028L2–L3Method defined
EG(k,z) scale-localised bump~7% excess at kc = 0.05 h/Mpc from band-pass stiffness R(k,a); testable at 2.5–3.5σDESI DR3 × Planck lensing (EG estimator)~2027–2028L1–L231985313
Lensing crossover Σeff(z)Sign-changing tomographic response: Σeff > 1 at z < 0.4 (+2.6% at z=0.10), crossover at z ≈ 0.44, Σeff < 1 at z > 0.5 (−1.5% at z=1.21). Non-monotonic, distinctive within MG model class.Euclid DR1 tomographic cosmic shear (6 bins over 0.2–1.4)2026 OctL1–L232037990
Structural signature μ < 1 ∧ Σ ≥ 1Growth suppression (μ < 1) with lensing enhancement (Σ ≥ 1), strongly disfavored in standard QS Horndeski with αT=0 (numerical scan, 135k points). Enabled by λ-constraint anisotropic stress.Euclid DR1 μ–Σ tomography; SO × Euclid EG2026–2028L1–L232037990

3. Statistical Evaluation Framework

3.1 Likelihood and Model Comparison

ElementSpecification
Likelihood formGaussian likelihood assumed for all Stage-IV probes unless survey documentation specifies otherwise. For cosmic shear: L ∝ exp(−½ ΔdT C−1 Δd) where d is the data vector and C the covariance.
Data vectorsProbe-specific: shear C (Euclid); P(k) multipoles + BAO (DESI); fσ8(z) (RSD compilation); CMB lensing Cφφ (Planck/ACT/SPT). Each data vector is defined by the survey collaboration.
CovarianceSurvey-provided covariance matrices are used in all cases. EFC does not introduce independent covariance estimates. Where survey covariance is unavailable, Fisher matrix projections from official survey specifications are used and explicitly flagged.
Model comparisonPrimary: Δχ² between EFC and ΛCDM. Secondary: ΔAIC = Δχ² + 2Δk. Bayesian evidence (ln B) reported where available but not used as primary criterion.
Parameter handlingEFC parameters (β, T(a), zt) are frozen in the Global Parameter Registry (Ledger). Standard cosmological parameters (Ωm, H₀, σ8, ns) are marginalised over with Planck 2018 + BAO priors unless stated otherwise. No probe-specific re-tuning is permitted.
Threshold interpretationKill criteria (KC) are evaluated as: if the best-fit EFC parameter falls within the stated null range at the stated confidence level, the sector is falsified. The confidence level is determined by the posterior width from the survey likelihood, not by an EFC-internal estimate.

3.2 Specific Threshold Definitions

CriterionObservableNull hypothesis (ΛCDM)EFC predictionEvaluation method
KC1αL2α = 0α ≈ −0.7Posterior from DESI DR3 fσ8 + BAO joint likelihood; falsified if 99.7% CI includes zero
KC2zcrossNo crossoverz = 2.042Profile likelihood on fσ8(z) trajectory; falsified if |zcross − 2.042| > 3σsurvey
KC3S8 ratioS8lens/S8CMB = 10.95 ± 0.03Ratio of Euclid DR1 S8 to CMB lensing 2026 baseline; falsified if ratio = 1.000 ± 0.005
KC4η − 1η = 1η ≈ 1.10EG statistic from Euclid DR2 lensing×RSD; falsified if |η − 1| < 0.01 at 3σ
KC5w₀ + 1w₀ = −1w₀ ≠ −1Euclid + DESI BAO joint posterior; falsified if |w₀ + 1| < 0.02 at 3σ

4. Systematics Control

The governing principle is: EFC uses survey-provided systematics budgets and does not introduce its own nuisance parameters beyond those in the Global Parameter Registry.

ObservableDominant SystematicsHandlingReference
S8 (cosmic shear)Intrinsic alignments (IA); shear calibration bias (m); photometric redshift errors (Δz)Marginalised using survey-provided IA model (NLA or TATT) and m/Δz priors from Euclid calibration pipeline. EFC Case A test verified: not IA compensation (IA=0 gives 63% persistence); not just amplitude (Δ=41 residual after As tuning).31271917
8 (RSD)Galaxy bias model; fibre collisions; RSD modellingUses DESI/BOSS official pipeline. MVP-G1 LOO robustness demonstrated: signal stable across all 7 folds (spread = 0.23 in α).31332730
CMB lensingBeam systematics; foreground residuals; noise biasBaseline fixed by Planck/ACT/SPT collaboration. EFC does not modify the reconstruction pipeline.Qu et al. 2026
BAOReconstruction method; template fitting; fiducial cosmologyUses survey-provided consensus measurements with full covariance. BAO covariance-aware test passed (Δχ² = −3.0).31314922
P(k) full-shapeBaryonic feedback; non-linear modelling; shot noiseScale cuts applied following survey specifications (kmax ≈ 0.20–0.25 h/Mpc). See §6 for degeneracy.Method defined
ISWTracer bias; foreground contaminationEFC prediction (AISW ≈ 0.89) is tracer-independent by construction.31329082
Void ISW stackingVoid finder algorithm; aperture photometryDepth-binned protocol pre-specified. Sign-flip is qualitative (cold→hot for δ ≲ −0.8).31942677
Cluster κ mapsPSF modelling; source redshift distributionPre-registered directional residual estimator (Asig) insensitive to azimuthally symmetric systematics.Methodology locked (2026)
Solar System (PPN)Spacecraft systematics; ephemeris modelCassini/LLR constraints taken as published. Density Saturation ensures Θ(ρ) → 0 at solar densities.31244827

5. Blinding and Analysis Protocol

5.1 Prediction Integrity

ElementImplementation
Sealed predictionsTwo cryptographic freezes (SHA-256) deposited before data release. Hash 7a850cfa... (2026-02-18) and dbccda15... (2026-02-21). Full parameter sets recoverable from hash verification.
Kill criteria frozenKC1–KC5 thresholds defined in White Paper and deposited via Figshare DOI (31970904) before any Stage-IV data release.
Parameter freezeGlobal Parameter Registry (Ledger) governs all shared parameters. No parameter may be modified between prediction deposit and analysis completion.

5.2 Analysis Execution

ElementImplementation
Pipeline versioningAll analysis code maintained in github.com/supertedai/EFC. Git commit hash recorded at analysis time. No code modifications after data unblinding.
Survey pipelinesOfficial pipeline version used without modification. Version and configuration documented.
No post-hoc tuningAfter unblinding, prohibited: (i) modifying EFC parameters, (ii) changing scale cuts, (iii) switching likelihood forms, (iv) adding/removing probes. If necessary, restart as exploratory analysis (clearly labeled).
Reporting obligationAll results — including failures — reported in the Ledger within one revision cycle. Suppression prohibited under Core Lock v1.0.

6. Degeneracy and Discriminant Structure

The key discriminant is that EFC predicts a specific combination of μ < 1, Σ > 1, and η ≈ 1.10 simultaneously — a pattern rare or absent in competing models.

6.1 What Can Mimic EFC

Competing EffectMimics Which EFC SignalWhere It FailsDiscriminating Observable
Massive neutrinosGrowth suppression (lower σ8/S8)η = 1 exactly; scale-dependent; no galactic RARη via EG (KC4); scale-dependence of fσ8(k); SPARC
Baryonic feedbackP(k) suppression; lower S8Confined to k > 0.5 h/Mpc; no ISW; η = 1Scale cuts; ISW (F1); gravitational slip (KC4)
f(R) gravityμ ≠ 1; modified growthμ > 1 (wrong sign); Σ = μ; different screeningSign of μ (FA2); μ vs Σ (Euclid DR2)
Horndeski / EFT of DEGeneral μ(k,z), Σ(k,z)Standard QS Horndeski with αT=0: μ < 1 ∧ Σ > 1 strongly disfavored (numerical scan, 135k points finds max Σ=0.989 when μ<0.99; see 32037990). EFC’s λ-constraint mechanism is structurally distinct.Joint μ–Σ (Euclid DR1/DR2); tomographic Σeff(z) sign change
w₀waCDMModified expansion; BAO shiftsμ = Σ = η = 1 in perturbationsPerturbation-sector: fσ8, EG, void ISW
Phenomenological AL > 1Enhanced CMB lensingNo perturbation-sector origin; no additional predictionsGalaxy lensing + fσ8 joint; see 31368433

6.2 The EFC Discriminant Signature

PropertyEFCMassive νf(R)Horndeski (QS, αT=0)w₀waCDM
μ < 1 (structural)✓ Robust (100%)✗ (μ > 1)✗ Disfavored by scan
Σ ≥ 1 (with μ < 1)✓ Semi-robust (61%)✗ (Σ ≈ μ)✗ Disfavored by scan
Σeff(z) sign change at z≈0.44✓ Non-monotonicDistinctive within class
Void ISW sign-flip
Galactic RAR✓ (k = 0.415)Partial

Bottom line: The structural signature μ < 1 ∧ Σ ≥ 1 combined with a non-monotonic Σeff(z) crossover at z ≈ 0.44 (32037990) is the most distinctive observational test within the current MG model class. Euclid DR1 tomographic cosmic shear (October 2026) is the decisive instrument: percent-level sensitivity over 0.2 < z < 1.4 is exactly the regime where the predicted crossover lives. Earlier framing emphasised η ≈ 1.10 as a point prediction; structural analysis shows that value is fragile at ±20% parameter variation (0% robustness) while the μ < 1 signature survives.


7. Failure Response Protocol

LevelConditionsConsequence if TriggeredScope of Revision
Kill Criterion (KC)KC1–KC5Hard falsification of the specified sector. Formally abandoned. Documented in Ledger within one revision cycle.Sector-specific: KC1 kills growth; KC3 kills S8 channel; etc.
Action-Level (FA)FA1–FA6Theory-level rejection of the Relativistic Action. Must be revised or replaced.Perturbation sector only. Galactic sector unaffected.
Standing Falsification (F)F1–F6Tension / revision trigger. Framework may survive if other channels compensate.Channel-specific.

7.1 Compound Failure Rules

ScenarioInterpretation
1 KC triggered, others passSector falsified. Remaining framework viable but reduced. Documented as partial falsification.
2+ KC triggeredFramework-level crisis. Perturbation sector abandoned if growth + lensing + slip all fail.
KC passes but FA failsEmpirical signal survives but derivation wrong. Action must be revised.
All KC pass, all FA passConfirmation ladder advances. Survival, not proof.
Sealed prediction within 1σStrong support. Reported as pre-registered confirmation.
Sealed prediction within 2σConsistent. No action required.
Sealed prediction beyond 3σPrediction falsified. Documented. Exploratory re-estimation permitted (clearly labeled).

Governance commitment: The failure response protocol is frozen at publication. No reclassification of KC → F or FA → F post-data. Historical falsifications (Ledger) demonstrate EFC has already applied this protocol to itself.


8. Mapping to Standard Parameterisations

Standard FrameworkEFC MappingNotes
μ(k,z), Σ(k,z)At linear scales μ ≈ 0.94, Σ ≈ 1.05, η ≈ 1.10. Scale dependence via stiffness response R ∝ k−4.Directly comparable to Euclid MG pipeline. See 31876324.
w₀waCDMEFC: w(a) = −β(S)·a. Not a free fit — derived from susceptibility T(S). Effective w₀, wa extractable by Taylor expansion.See WP Part 4.
EFT of DE (α-functions)DERIVED (32011407). αT = 0; αM ∝ S(a); αB ∝ dS/d ln a. Stiffness response R(k,z) beyond standard Horndeski.DONE. Predictions sealed in 32010399.
ΣmνEFC growth suppression partially degenerates with neutrino mass. EFC’s η ≠ 1 breaks the degeneracy.Neutrino mass constraints from EFC+DESI will differ from ΛCDM+DESI.

9. Critical Path: What Must Be Ready Before Data Arrives

PriorityItemRequired ForDeadlineStatus
1Euclid DR1 S8 extraction pipelineKC3; P3 replication2026 OctPREDICTION READY hi_class + efc_logistic; benchmark frozen (31990053, SHA-256 sealed 2026-04-12)
2ISW cross-correlation (AISW)F12026 H2PREDICTION READY ClTT(ℓ=30): +1.88% at benchmark
3EG estimator implementationKC4; FA4~2028PREDICTION READY EG(ℓ=66): −3.98% from Clφφ/P(k) ratio
4Full-shape P(k) likelihood with EFC growthKC1; F4~2027PREDICTION READY P(kc,z=0.5): +2.09% via hi_class Boltzmann
5Void catalogue + ISW stackingVoid ISW sign-flip~2028METHOD DEFINED
6Cluster shock-front κ analysisF32026–2027PRE-REGISTERED
7EFCLASS Boltzmann solverFull C; ADM Hamiltonian~2028PLANNED
8BAO anisotropic splitSealed DH/rd~2027PREDICTION READY

10. Confirmation Ladder (Updated)

LevelThresholdChannels RequiredSurvey(s)TimelineStatus
Hint (current)2.20σ single-channel8 LOO (7/7)DESI DR1 + BOSS2026ACHIEVED
Suggestive3σ joint8 + S8+ Euclid DR1 + DES Y62027AWAITING Euclid DR1
Evidence3.5σμ–Σ + fσ8+ Euclid DR22028Requires KC4 + EG pipeline
DetectionAll channels lockedEuclid DR3 + Rubin + DESI final2030+Requires all KC1–KC5 not triggered

11. Cross-Domain Predictions (Non-Cosmological)

PredictionDomainCriterionDatasetReference
P4** — η = Ceff/DratioγNeuroscience (Track 2)|r| > 0.40 on n ≥ 20 subjectsHCP structural connectome + multiscale entropy31940547
P5 — Optimal βKL from resting-state fMRIAI Alignment (Track 3)Calibrate RLHF temperature without grid searchHCP fMRI + RLHF training runs31940547
P2 — Grokking phase transitionAI Alignment (Track 3)Δtgrok ~ (Hmem − Hgen)/Teff; falsified if r < 0.3Modular arithmetic datasets31940535
Centrifugal gradient (P1, Track 2)NeuroscienceCore-to-periphery entropy production gradientHCP connectome + resting-state fMRI31940505

12. Gap Analysis (April 2026)

Living assessment of what the project needs vs what exists. Updated monthly or on significant external events. Last update: 2026-04-17.

12.1 External Landscape Changes Since Last Roadmap Version

EventDateImpact on EFCAction Required
CMB-S4 cancelledJuly 2025Primary future CMB lensing instrument lost. Sub-percent CMB lensing now depends on Simons Observatory + LiteBIRD (2032+).Update all CMB-S4 references in roadmap. Simons Observatory is the effective near-term replacement.
Simons Observatory LAT first lightFeb–Mar 2025CMB lensing reconstruction capability now operational. First SO × Euclid cross-correlation data expected ~2027.DONE — EG pre-registration sealed (32023788): EGEFC/EGGR = 1.086 ± 0.012.
Rubin/LSST first photonsApr 2025Survey now operational. DP2 expected Jul–Sep 2026. DR1 ~early 2028.DONE — Rubin DP2 cosmic shear sealed (32013738): S8 = 0.847 ± 0.015, ξ+ ~8% enhancement.
DES Year 6 3×2pt releasedJan 2026S8 = 0.789 ± 0.012. P3 PASS at 0.3σ. 2.6σ tension with CMB.Completed. Result logged in Ledger v3.9.
DESI DR2 BAO releasedMar 20252.8–4.2σ preference for w₀waCDM over ΛCDM. f(R) models strongly preferred.Verify αL2 against DR2 chains. EFC regime fit shows ΔAIC = −18.01 (31230703).
DESI DR1 peculiar velocity fσ8Dec 20258(z=0.07) = 0.450 ± 0.055. Low-z, low discriminating power for EFC.Monitor. DR2 full-shape RSD at z~0.5–0.7 is the key pending test.
Entropic gravity competitors2025–2026Multiple arXiv papers (2503.19056, 2503.08236, 2512.22103, 2508.13260) show entropic cosmology models statistically preferred over ΛCDM with DESI DR2. Competitive landscape intensifying.Differentiate EFC via the perturbation-sector discriminant signature (μ<1, Σ>1, η≈1.10) which competitors lack.

12.2 Kill Criteria Readiness

KCPipeline StatusGapPriority
KC1 P(k) full-shapePREDICTION READYNone — hi_class + efc_logistic sealed (31990053). Awaiting DESI DR3 (~2027).Low (pipeline complete)
KC28 trajectorySEALEDNone — sealed prediction zcross = 2.042. Awaiting DESI DR3 Lyα + high-z RSD.Low (prediction locked)
KC3 S8 convergenceP3 PASSDES Y6 passed (0.3σ). KiDS Legacy divergence unresolved. Euclid DR1 (Oct 2026) will arbitrate.Medium (Euclid pipeline ready, need to monitor KiDS Legacy release ~2027)
KC4 Gravitational slip ηSEALEDAll KC4 channels pre-registered: SO × Euclid EG (32023788: EGEFC/EGGR = 1.086 ± 0.012, kill at 1.00 ± 0.01 >3σ), Rubin DP2 cosmic shear (32013738), μ–Σ eigenmode (31990194).DONE
KC5 Dark energy w(z)MonitoringDESI DR2 shows 2.3σ for w₀waCDM. EFC consistent. Gap: need formal w(a) = −β(S)·a prediction confronted with Euclid DR1 chains.Medium — derive effective w₀, wa from EFC susceptibility

12.3 Theory Gaps

GapStatusBlockingPriority
Bellini–Sawicki α-function mappingCLOSED (32011407)Euclid EFT pipeline compatibilityDONE — αT=0, αM∝S(a), αB∝dS/d ln a
Full non-linear ADM Hamiltonian stabilityPassed at 2nd order; full non-linear pendingFA6Medium
EFCLASS Boltzmann solverPartial (hi_class patch exists)Full C predictionsMedium — hi_class efc_logistic covers the key regime
Multi-component 175-galaxy SPARC universalityCLOSED (32029704)Final rotation-curve validationDONE

12.4 Priority Actions

  1. IMMEDIATE (Apr–Jun 2026): Monitor DESI for release of DR2 full-shape RSD paper at z~0.5–0.7. This is the only currently pending direct test of the sealed prediction fσ8(z=0.7) = 0.430. Bellini–Sawicki α-functions: DONE (32011407). Pre-registered predictions sealed (32010399).
  2. BY JULY 2026: Pre-register EFC predictions for Rubin/LSST DP2 cosmic shear. DONE (32013738): S8 = 0.847 ± 0.015, ξ+ ~8% large-scale enhancement (20′–300′), SHA-256 sealed.
  3. BY SEPTEMBER 2026: Pre-register EFC predictions for Simons Observatory × Euclid EG cross-correlation. DONE (32023788): EGEFC/EGGR = 1.086 ± 0.012 at kc ≈ 0.05 h Mpc−1, zeff ≈ 0.5. Pass window [1.03, 1.14], kill at 1.00 ± 0.01 (>3σ). Sealed 15 Apr 2026.
  4. BEFORE OCTOBER 2026: Euclid DR1 pre-registration is sealed (31990053). Verify pipeline scripts and Boltzmann outputs are version-controlled and DOI-stamped.
  5. 2027: Derive effective w₀, wa from EFC susceptibility T(S) for confrontation with Euclid DR1 + DESI DR3 joint chains.

12.5 Competitor Landscape

ModelarXivKey ClaimEFC Differentiator
Modified entropic gravity (Odintsov+)2503.08236Modified Friedmann from extended entropy; fits Pantheon+BAO+PlanckEFC has perturbation-sector predictions (μ<1, Σ>1, η); competitor is background-only
Mass-to-horizon entropic cosmology2508.13260, 2512.22103Bayesian analysis vs DESI DR2 BAO; preferred over ΛCDMEFC has galactic-scale RAR (k=0.415) and cross-scale P3 link; competitor lacks galactic sector
f(R) gravity (DESI DR2)2504.05432Starobinsky/Exponential f(R) strongly preferred with DESI DR2EFC has μ<1 (f(R) has μ>1); sign of μ is the discriminant (FA2)
Ray-traced screened MG for LSST2604.08393LSST weak-lensing predictions for screened MGMethodological template — EFC should adapt for its own LSST predictions

Bottom Line

PurposeMap every Stage-IV data release to a specific, pre-registered EFC test
Next critical date2026 Oct 21 — Euclid DR1: tests KC3, KC5, FA2, P3 replication
Sealed predictions2 cryptographic freezes; 6 quantitative values; testable by DESI DR3 (~2027–2028)
Kill criteria5 (KC1–KC5) + 6 action-level (FA1–FA6) + 6 standing (F1–F6) = 17 falsification conditions
Pipeline gaps1 item before data arrival (void stacking); EG, full-shape P(k), and S8 pipelines now complete via hi_class efc_logistic (2026-04-12)
Statistical frameworkSurvey-provided likelihoods/covariance; Δχ² / ΔAIC primary; no EFC nuisance parameters
Key discriminantη ≈ 1.10 — rules out massive neutrinos, f(R), w₀waCDM if confirmed
Failure protocolKC = hard kill; FA = action revision; F = tension. No reclassification post-data.
GovernanceFrozen at publication; versioned updates only before data release

Resources


© 2026 Energy-Flow Cosmology Initiative · Stage-IV Data Roadmap (v1.1 – April 2026)