Intrinsic Response Sector
as Dark Gravity
A GR-Compatible Candidate Identity for the Cold Dark Matter Role
Robert D. Kitcey · Independent Researcher · ORCID: 0009-0004-8679-9155
Working within standard general relativity, we define a response-sector stress–energy as the minimal effective source required so that galactic kinematics satisfy the Einstein equation with baryons alone — tested against 175 SPARC galaxies, achieving very strong improvement in 92% of systems.
Empirical Results
SPARC-175 Validation
The one-parameter closure applied to 175 galaxies from the SPARC database yields robust, statistically significant improvement across the full sample.
Organizing Principle
The Field Equation Framework
The Einstein tensor is kept standard. The response sector T^resp_μν is the minimal effective source required so that galactic kinematics satisfy the field equation with baryons fixed by SPARC mass models.
Ontologically Agnostic
The response sector is not a new particle. It is best read as an EFT/constitutive-closure candidate — an emergent metric response to baryonic structure.
Falsification-First
Explicit discriminants ladder: weak lensing, strong lensing, cluster dynamics, merger systems, and cosmological structure formation.
Low Degrees of Freedom
A single free parameter Q per galaxy — the asymptotic extra v² contribution — compresses the residual freedom with BIC-validated parsimony.
Research Visualization
Intrinsic Response in Galactic Spacetime
Figure: Intrinsic Response in Galactic Spacetime. The diagram illustrates the baryonic density gradient, transition radius R_t, auxiliary field amplitude Q, oscillatory metric response, and the asymptotic extra v² contribution.
Radial Residual Analysis
Oscillatory Metric Response
The velocity-squared deficit Δ(R) = V²_obs − V²_bar reveals a structured oscillatory pattern in 46 of 175 SPARC galaxies — a signature of boundary-layer standing waves with median half-wavelength scaling to R_max rather than a cosmological constant.
Compression zones (Δ > 0) and rarefaction zones (Δ < 0) are separated by nodal radii where V²_obs = V²_bar exactly — a testable prediction of morphological ring features.
Falsifiability
The Discriminants Ladder
A pre-registered validation plan with explicit falsification criteria at each rung, moving the debate from philosophical preference to empirical adjudication.
| Rung | Test | Observable | Falsifier |
|---|---|---|---|
| 1 | Weak Lensing | Lensing vs. dynamical mass profiles for matched galaxy samples | Systematic deviation requiring η ≠ 1 or independent dark fluid |
| 2 | Strong Lensing | Lensing potential Φ+Ψ from lens modeling and time-delay cosmography | Inability to fit strong-lens systems without independent dark component |
| 3 | Cluster Dynamics | Scaling relations: lensing mass, X-ray gas temperature, velocity dispersions | Large independent dark mass not constitutively determined by baryons |
| 4 | Merger Systems | Gas/stellar/lensing centroid offsets in merging clusters (Bullet Cluster) | Offset patterns incompatible with any plausible response activation rule |
| 5 | Cosmology | CMB acoustic peaks, CMB lensing, matter power spectrum growth | Inability to reproduce structure formation without separately conserved CDM |
Full Paper Available
Intrinsic Response Sector as Dark Gravity
SPARC-175 · Preprint Draft v5.0.5.7 · February 2026 · 64 pages
Licensed under CC BY-NC-ND 4.0