RMB Cosmology I: A Covariant Motion–Space Coupling with Dynamical Screening and a Mild Late-Time Enhancement of the Hubble Rate

This work presents the first covariant cosmological formulation of the RMB 
(Raum–Materie–Bewegung) theory, in which motion acts as a geometric source 
of stress–energy. We construct the unique FRW-compatible RMB vector field 
Φμ = f(H) uμ and introduce a dynamical screening mechanism that suppresses 
the motion-induced stress term at early times while activating it near the 
present epoch.

A complete derivation of the modified Friedmann equations is given, 
including energy conservation, background stability, and the identification 
of a late-time attractor solution. The model naturally yields a mild 
enhancement of the late-time expansion rate H(z), offering a plausible 
mechanism that alleviates (but does not fully resolve) the Hubble tension 
without invoking dark energy or new scalar fields.

Four appendices provide the technical details: (A) tensorial derivation of 
the modified Friedmann equations, (B) energy conservation in an expanding 
background, (C) a dynamical-system analysis ensuring stability and the 
absence of divergences, and (D) implementation notes and numerical 
considerations. A representative H(z) comparison plot with ΛCDM is included.

This preprint establishes the theoretical groundwork for RMB Cosmology II, 
which will extend the framework to linear perturbations, structure 
formation, and observational data (BAO, SNe, CMB).