Wide Binaries and Dark-Matter-Free Dwarfs from a Curvature-Screened Fifth Force

We present predictions for wide-binary (WB) accelerations and dark-matter-free dwarf galax- ies from a curvature-screened scalar sector that modifies gravity only in low-curvature, low- density environments. The framework follows a zero–free-parameter galaxy phenomenology and uses the same field-theory equations to address stellar and galactic scales, without invoking par- ticle dark matter. In WBs, the environmental switch arises from the effective mass m2 eff(ρ, K) of the scalar field, which turns negative at low tidal curvature K and interstellar density ρ, activating a long-range fifth force. The amplitude is set by an unscreened plateau 1 + 2β2 out, while stellar compactness controls a thin-shell suppression. We calibrate a Chae-variant that matches (gobs/gN) ≈ 1.43 at gN ≃ 10−10.15 m s−2 and ≈ 1.12 at gN ≃ 10−8.91 m s−2, using (βout, ac, λϕ, S0, p) = (0.49, 8.00e − 10 m s−2, 0.50 pc, 4.0e − 06, 2.5). A Monte Carlo population of WB orbits reproduces the characteristic S-shaped transition with robust nulls at high ac- celerations. On galactic scales, the same setup explains NGC 1052–DF2/DF4 as baryon-only systems via environmental suppression of the X-sector within their half-light radii. We release figures and data products to enable reproduction of all results.

https://zenodo.org/records/17081673