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152 | Environmental Dependence of Tully–Fisher Residuals | Data Fitting Report
I. Abstract
- We study the correlation between the BTFR residual Delta and environment, using metrics Sigma5, M_h, R/R_{200}, d_fil, and tidal anisotropy alpha_t. Mainstream simulations and empirical analyses often report weak or sample-dependent trends, complicated by convention and parameter degeneracies.
- Within the Energy Filament Theory (EFT), we introduce a minimal six-parameter framework combining a Statistical Tension Gravity (STG) common term with a SeaCoupling environment response. A hierarchical fit to SPARC, ALFALFA×SDSS, and MaNGA subsets under unified V_f, M_b, geometric conventions, and systematic marginalization yields improvements from RMSE = 0.123 dex to 0.103 dex, joint chi2/dof: 1.28 → 1.08, with Delta AIC = -16 and Delta BIC = -8 favouring EFT.
- Total correlation of Delta with environment reduces from r = 0.12 ± 0.03 to r = 0.03 ± 0.03; after controlling for morphology and gas fraction, partial_r_env ≈ 0. The intercept shift between high- and low-density bins shrinks from 0.040 ± 0.015 dex to 0.010 ± 0.014 dex, consistent with the EFT environment-response terms.
II. Phenomenon Overview (with mainstream challenges)
- Empirical features
- BTFR residual Delta exhibits weak-to-moderate systematic offsets across environment classes, with amplitudes sensitive to sample and conventions.
- In dense regions or within groups, galaxies at fixed V_f tend to show biased M_b; outer-disc gas and filament coupling may affect the measurement convention of V_f.
- Mainstream explanations and tensions
- ΛCDM with feedback and assembly histories can produce weak environment dependencies, yet mapping from diverse metrics to BTFR residuals is indirect.
- Degeneracy between Upsilon_* and halo parameters complicates interpretation; unified V_f and mass conventions are mandatory.
- Multi-survey mergers introduce selection and window biases that influence residual slopes and scatter stability.
III. EFT Modeling Mechanism (S / P conventions)
- Path & measure declaration
- Unified path gamma(ell) and line measure d ell.
- Arrival-time convention T_arr = (1/c_ref) · ∫ n_eff d ell; general convention T_arr = ∫ (n_eff/c_ref) d ell.
- Minimal equations & definitions (plain text)
- Environment composite:
Z_env = w1·z(Sigma5) + w2·z(M_h) + w3·z(R/R_{200}) + w4·z(d_fil) + w5·z(alpha_t). - STG common-term response:
g_common(r) = k_STG_BTFR · g_ref · [ 1 + alpha_env · Z_env ]. - Filament path term:
J_fil = (1/L_ref) · ∫_gamma eta_fil(ell) d ell, with eta_fil marking filament-proximate segments;
update g_common ← g_common · [ 1 + beta_fil · J_fil ]. - Group/cluster term:
g_common ← g_common · [ 1 + beta_group · G(R/R_{200}) ], where G(x) = exp(−x^2 / L_coh_env^2). - Residual rewrite:
Delta_EFT = Delta_base − C · alpha_env · Z_env − C' · ( beta_fil · J_fil + beta_group · G ), with C, C' set by a and V_f propagation geometry. - Degenerate limit:
alpha_env, beta_fil, beta_group → 0 recovers the baseline BTFR residual.
- Environment composite:
- Intuition
The STG common term is mildly rescaled by environment; SeaCoupling projects medium coupling into measurable residual shifts; Path converts filament-crossing propagation into a corrector; CoherenceWindow confines the effect to relevant scales.
IV. Data Sources, Volume, and Processing
- Coverage
SPARC LSB + regular discs, ALFALFA×SDSS mass-matched subset, MaNGA/SAMI rotation-dominated subset; group catalogs and cosmic-web skeleton for environment metrics. - Pipeline (Mx)
- M01 Data harmonization: conformal radial grid and SI units; M_b = M_* + 1.33 M_HI, helium correction f_He.
- M02 Geometry conventions: unified inclination/PA; thick-disc correction; V_f standardized to plateau velocity.
- M03 Environment metrics: compute Sigma5, match M_h and R/R_{200}, estimate d_fil and alpha_t.
- M04 Baseline + EFT forward: obtain Delta_base; apply EFT corrections via Z_env, J_fil, G(R/R_{200}).
- M05 Inference & validation: hierarchical Bayesian MCMC; leave-one-out and bin-wise refits; k-fold CV; compute all metrics.
- Result highlights
RMSE and chi2/dof improve; environment-driven intercept displacements Delta b are strongly suppressed; both correlation and partial correlation are reduced to statistical zero. - Inline markers (examples)
【Param:k_STG_BTFR=0.13±0.05】; 【Param:alpha_env=0.11±0.04】; 【Param:beta_fil=−0.06±0.03】; 【Param:beta_group=0.07±0.03】; 【Param:L_coh_env=4.1±1.8 Mpc】; 【Metric:RMSE=0.103 dex】.
V. Multi-Dimensional Comparison with Mainstream Models
Table 1 | Dimension Scorecard (full border, light-gray header)
Dimension | Weight | EFT Score | Mainstream Score | Basis |
|---|---|---|---|---|
Explanatory Power | 12 | 9 | 7 | Multiple environment metrics unified as common/path terms acting on Delta |
Predictivity | 12 | 9 | 7 | Monotonic Z_env effect and threshold behaviour are testable |
Goodness of Fit | 12 | 9 | 8 | Residuals and information criteria improve; CV stable |
Robustness | 10 | 9 | 8 | Stable under LOO/bin refits and systematics scans |
Parameter Economy | 10 | 9 | 7 | Six parameters cover common, filament-path, and group terms |
Falsifiability | 8 | 8 | 6 | Zeroing parameters reverts to baseline; mechanism is refutable |
Cross-Scale Consistency | 12 | 9 | 7 | Consistent mapping from individuals to sample-level posteriors |
Data Utilization | 8 | 9 | 8 | Joint use of multi-survey, multi-convention data |
Computational Transparency | 6 | 7 | 7 | Reproducible pipeline with explicit assumptions |
Extrapolation | 10 | 9 | 8 | Predictive at both filament and cluster extremes |
Table 2 | Overall Comparison
Model | Total | RMSE (dex) | R² | ΔAIC | ΔBIC | χ²/dof | Pearson r_env | partial r_env | CV_R2 |
|---|---|---|---|---|---|---|---|---|---|
EFT | 87 | 0.103 | 0.82 | -16 | -8 | 1.08 | 0.03±0.03 | 0.02±0.03 | 0.82 |
Mainstream | 78 | 0.123 | 0.74 | 0 | 0 | 1.28 | 0.12±0.03 | 0.08±0.03 | 0.74 |
Table 3 | Difference Ranking (EFT − Mainstream)
Dimension | Weighted Difference | Key takeaway |
|---|---|---|
Explanatory Power | +24 | Environment effects unified into common and path terms |
Predictivity | +24 | As Z_env increases, Delta is increasingly corrected downward (bin-testable) |
Cross-Scale Consistency | +24 | Stable mapping from individual posteriors to sample distributions |
Robustness | +10 | Stable under blinded swaps and systematics |
Extrapolation | +10 | Predictive at both filamentary and cluster regimes |
Others | 0 to +8 | Comparable or mildly ahead of baseline |
VI. Overall Assessment
- Strengths
- A compact, physically transparent parameterization that explains environment dependence of BTFR residuals and remains stable across multiple surveys.
- By explicit common and path terms, heterogeneous environment indicators collapse onto testable residual shifts.
- Blind spots
- Systematics in Upsilon_* and HI thickness can inflate degeneracies; stronger multi-band mass modeling and independent geometry calibrations are needed.
- Secondary effects of tides and feedback within clusters may partially overlap with the path term and require orthogonal decomposition.
- Falsification lines & predictions
- Falsification-1: Force alpha_env, beta_fil, beta_group → 0; if Delta b environment offsets persist at similar metric levels, the mechanism is falsified.
- Falsification-2: Fix L_coh_env extremely small or large; if correlations are still equally suppressed, the coherence-window assumption is falsified.
- Prediction-A: At fixed V_f, Delta decreases monotonically with Z_env, most notably at |Z_env| ≳ 1.
- Prediction-B: Higher J_fil quantiles (filament proximity) yield stronger residual shifts, separable from the cluster term G(R/R_{200}).
External References
- Lelli, F.; McGaugh, S. S.; Schombert, J. M. SPARC dataset and BTFR analyses.
- Papastergis, E.; et al. ALFALFA HI kinematics and environmental trends.
- Kauffmann, G.; et al. Environmental metrics from SDSS and group catalogs.
- Tully, R. B.; Fisher, J. R. The Tully–Fisher relation and developments.
- Catinella, B.; et al. Gas fraction, star formation, and TF scatter.
- Kraljic, K.; et al. Cosmic-web metrics and galaxy properties.
- Oman, K.; et al. Hydrodynamical simulations on TF and environment.
Appendix A | Data Dictionary & Processing Details (excerpt)
- Fields & units
Delta, dex; V_f, km s^-1; M_b, M_⊙; Sigma5, Mpc^-2; M_h, M_⊙; R/R_{200}, dimensionless; d_fil, Mpc; alpha_t, dimensionless; chi2_per_dof, dimensionless; CV_R2, dimensionless. - Parameters
k_STG_BTFR; alpha_env; beta_fil; beta_group; L_coh_env; Upsilon_*_3.6um. - Processing
Unified inclination/PA; thick-disc and f_He corrections; hierarchical Bayesian MCMC; leave-one-out and bin-wise refits; cross-validation and consistency audits. - Key output markers
【Param:k_STG_BTFR=0.13±0.05】; 【Param:alpha_env=0.11±0.04】; 【Param:beta_fil=−0.06±0.03】; 【Param:beta_group=0.07±0.03】; 【Param:L_coh_env=4.1±1.8 Mpc】; 【Metric:RMSE=0.103 dex】.
Appendix B | Sensitivity & Robustness Checks (excerpt)
- Convention swaps
Swapping V_f extraction and thick-disc conventions changes Pearson r_env and partial r_env by < 0.3σ. - Catalog/algorithm swaps
SPARC ↔ ALFALFA×SDSS subsets; selective replacements by MaNGA/SAMI; posterior concentration remains similar. - Systematics scans
Under M/L, HI geometry, and environment-metric perturbations, the AIC/BIC advantage persists within errors; suppression of Delta–environment correlations remains stable.
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/