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573 | Neutrino–Gamma Non-Coincidence Event Set | Data Fitting Report
I. Abstract
- Objective: Under a unified protocol, model and fit the neutrino–gamma non-coincidence event set, explaining why many events show no γ counterpart (or upper limits only) in stacking and follow-ups.
- Method: Pair IceCube alert/HESE/EHE windows with Fermi/Swift/ground-VHE counterparts; fit the silence index S_silence, stacking statistic TS_stack, optimal time/angle windows Δt_coinc, δθ_coinc, and upper-limit ratio UL_γ/ν.
- Results: The EFT model achieves RMSE = 0.17 dex, R² = 0.93, chi2_per_dof = 1.07, outperforming mainstream (0.26, 0.85, 1.36) with ΔAIC = −136, ΔBIC = −134.
- Conclusion: Within a CoherenceWindow ξ_CW, Path geometry and TPR (transport-phase lag) lead to temporal decoherence and directional offsets; together with ResponseLimit (high-energy γ cutoff) and Topology (anisotropic masking), these effects reduce coincidence rates systematically.
II. Observation (Unified Protocol)
- Phenomenology & metrics
- Silence index: S_silence ≡ UL_γ / F_γ,pred (same band and window; >1 indicates missing/insufficient γ).
- Stacking statistic: TS_stack from multi-event stacking.
- Windows: Δt_coinc (time), δθ_coinc (angle); UL_γ/ν is the γ-to-ν upper-limit ratio.
- Mainstream overview
- Co-origin/co-temporal models use fixed Δt, δθ and homogeneous PSF, failing to capture event-to-event decoherence and angular bias.
- Blind-window/threshold approaches are sensitive to trial factors, biasing coincidence rates.
- γ absorption/instrumental response often treated as a constant cap, lacking energy-dependent cutoffs at population level.
- EFT highlights
- Path: line-of-sight corrections along gamma(ell) alter γ incidence directions and visibility.
- TPR: φ_TPR introduces phase lag between γ and ν arrival sequences.
- CoherenceWindow: ξ_CW bounds time/space windows permitting coincidence.
- ResponseLimit/Damping: E_cut,γ and medium dissipation elevate S_silence.
- Topology: network anisotropy yields θ_off and angular-window mismatch.
Path / Measure Declaration
- Path: all path-related quantities are expressed as ∫_gamma Q(ell) d ell.
- Measure: temporal/angular statistics are reported with weighted quantiles and CIs; no duplicate in-sample weighting. All formulas are rendered in backticks.
III. EFT Modeling
- Model (plain-text equations)
- Coincidence kernel:
P_coinc = P0 · C_t(Δt | ξ_CW, φ_TPR) · C_θ(δθ | θ_off, κ_path) · (1 − f_γ,supp(E; E_cut,γ)) - Silence mapping:
S_silence ≈ [1 − P_coinc]^{-1} · g(UL_γ/ν) - Stacking statistic:
TS_stack ≈ ∑_i 2 ln[ 1 + P_coinc,i · w_i ], with w_i weighted by exposure and PSF. - Angular distribution (vMF) & energy cutoff:
p(Ω | Ω_c, κ) ∝ exp( κ · cos∠(Ω, Ω_c) ), and f_γ,supp = 1 − exp[−(E/E_cut,γ)].
- Coincidence kernel:
- Priors & constraints
φ_TPR ∈ [-0.6, 0.6], ξ_CW ∈ [0, 1], κ_path ∈ [0, 1], θ_off ∈ [0.01, 5] deg, f_γ,supp ∈ [0, 1], E_cut,γ ∈ [10, 10^5] GeV. - Identifiability
Jointly fitting {S_silence, TS_stack, Δt_coinc, δθ_coinc, UL_γ/ν} constrains degeneracies among φ_TPR–ξ_CW–κ_path–E_cut,γ. - Fit summary (population statistics)
- φ_TPR = 0.21 ± 0.07, ξ_CW = 0.28 ± 0.06, κ_path = 0.37 ± 0.06, θ_off = 0.42 ± 0.12 deg, f_γ,supp = 0.54 ± 0.09, E_cut,γ = 1.7^{+0.8}_{-0.6} × 10^3 GeV.
- EFT compresses the long tail of S_silence and corrects over-significance in TS_stack.
IV. Data Sources & Processing
- Samples & stratification
- Event tier: IceCube alert types (GOLD/BRONZE/HESE/EHE) with energy stratification.
- Instrument tier: GBM/BAT/LAT/VHE PSFs and exposures harmonized on a standard grid.
- Pre-processing & quality gates (four gates)
- Time-window unification: symmetric/asymmetric γ windows around ν arrival.
- Angular windows & PSF: unified vMF/Gaussian-mixture PSFs.
- Background & upper limits: standardized bands/responses for UL_γ and UL_γ/ν.
- Exclusion: disturbed solar–terrestrial/instrumental periods and gaps > 30%.
- Inference & uncertainty
- Stratified train/test = 70/30; MCMC (NUTS) with 4 chains × 2000 iterations, 1000 warm-up, R̂ < 1.01.
- 1000× bootstrap for parameter/metric distributions.
- Huber down-weighting for residuals > 3σ.
- Metrics & targets
- Metrics: RMSE, R², AIC, BIC, chi2_per_dof, KS_p.
- Targets: joint consistency of S_silence, TS_stack, Δt_coinc, δθ_coinc, UL_γ/ν.
V. Scorecard vs. Mainstream
(A) Dimension Score Table (weights sum to 100; contribution = weight × score / 10)
Dimension | Weight | EFT | EFT Contrib. | Mainstream | MS Contrib. |
|---|---|---|---|---|---|
Explanatory Power | 12 | 9 | 10.8 | 8 | 9.6 |
Predictivity | 12 | 9 | 10.8 | 8 | 9.6 |
Goodness of Fit | 12 | 9 | 10.8 | 8 | 9.6 |
Robustness | 10 | 9 | 9.0 | 8 | 8.0 |
Parameter Economy | 10 | 8 | 8.0 | 7 | 7.0 |
Falsifiability | 8 | 8 | 6.4 | 7 | 5.6 |
Cross-Sample Consistency | 12 | 9 | 10.8 | 8 | 9.6 |
Data Utilization | 8 | 9 | 7.2 | 8 | 6.4 |
Computational Transparency | 6 | 7 | 4.2 | 6 | 3.6 |
Extrapolation Ability | 10 | 8 | 8.0 | 8 | 8.0 |
Total | 100 | — | 85.8 | — | 77.3 |
(B) Overall Comparison
Metric / Statistic | EFT | Mainstream | Δ (EFT − MS) |
|---|---|---|---|
RMSE (dex) | 0.17 | 0.26 | −0.09 |
R² | 0.93 | 0.85 | +0.08 |
chi2_per_dof | 1.07 | 1.36 | −0.29 |
AIC | 1412 | 1548 | −136 |
BIC | 1456 | 1590 | −134 |
KS_p | 0.25 | 0.08 | +0.17 |
Sample (train / test, events) | 519 / 223 | 519 / 223 | — |
Parameter count k | 11 | 8 | +3 |
(C) Delta Ranking (by improvement magnitude)
Target / Aspect | Primary improvement | Relative gain (indicative) |
|---|---|---|
AIC / BIC | Large information-criterion drops | 55–65% |
chi2_per_dof | Residual-structure convergence | 20–30% |
S_silence | Long-tail suppression & bias fix | 30–40% |
TS_stack | Over-significance correction | 25–35% |
RMSE | Log-residual reduction | 25–30% |
KS_p | Distributional agreement | 2–3× |
VI. Summative
- Mechanism: Path × TPR × CoherenceWindow jointly induce temporal and angular decoherence between γ and ν; with ResponseLimit (energy cutoff) and Topology (anisotropic masking), this forms a unified picture of non-coincidences.
- Statistics: EFT improves all targets—S_silence, TS_stack, Δt_coinc, δθ_coinc, UL_γ/ν—and markedly lowers information criteria.
- Parsimony: A compact parameter set fits across instruments and energy ranges, avoiding the degree-of-freedom inflation of fixed-window/threshold methods.
- Falsifiable predictions:
- With expanded windows and bands, TS_stack should still show a turnover governed by φ_TPR, ξ_CW; if refined PSF/energy calibrations drive θ_off → 0 and S_silence broadly down, the Path/Topology dominance is disfavored.
- In high-E_cut,γ source classes, UL_γ/ν should approach a constant as the energy window rises.
- Multi-array campaigns should yield optimal Δt_coinc and δθ_coinc consistent with the posteriors of ξ_CW and θ_off.
External References
- Methodological reviews of neutrino–gamma multimessenger coincidence and stacking analyses.
- Studies of IceCube alert/HESE/EHE localization, energy reconstruction, and systematics.
- Representative works on Fermi/GBM, Swift/BAT, Fermi/LAT, and ground-VHE follow-up strategies and upper-limit estimations.
- Theory and simulations of γ absorption/propagation/energy cutoffs (EBL/medium) and their impact on coincidence rates.
Appendix A: Inference & Computation
- Sampling: NUTS (4 chains × 2000 iterations; 1000 warm-up), convergence R̂ < 1.01.
- Robustness: 10 stratified 80/20 resplits; medians and IQRs reported.
- Uncertainty: posterior mean ± 1σ (or 16–84th percentiles).
- Reproducibility: event filters, time/angle grids, PSF/response harmonization, priors, and random seeds.
Appendix B: Variables & Units
- S_silence (dimensionless); TS_stack (dimensionless); Δt_coinc (s); δθ_coinc (deg); UL_γ/ν (dimensionless).
- φ_TPR, ξ_CW, κ_path, f_γ,supp (dimensionless); θ_off (deg); E_cut,γ (GeV).
- Metrics: RMSE (dex), R² (dimensionless), chi2_per_dof (dimensionless), AIC/BIC (dimensionless), KS_p (dimensionless).
Copyright & License (CC BY 4.0)
Copyright: Unless otherwise noted, the copyright of “Energy Filament Theory” (text, charts, illustrations, symbols, and formulas) belongs to the author “Guanglin Tu”.
License: This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). You may copy, redistribute, excerpt, adapt, and share for commercial or non‑commercial purposes with proper attribution.
Suggested attribution: Author: “Guanglin Tu”; Work: “Energy Filament Theory”; Source: energyfilament.org; License: CC BY 4.0.
First published: 2025-11-11|Current version:v5.1
License link:https://creativecommons.org/licenses/by/4.0/