Defect Cartan Gravity II: Static Forces, Cosmological Growth, and Observable Closures

We derive the principal observable consequences of Defect Cartan Gravity in the uniquetheory branch fixed in Paper I: a parity-even quadratic Cartan subset with only a spin-0+torsion/connection excitation. We first derive the static weak-field limit and show that spinlesssources generate a Newtonian potential with a single additional Yukawa channel. We providea benchmark amplitude αY = 1/3 in the decoupling limit where the scalar sector reducesto the standard R + βR2 scalar-tensor form, and parameterize torsion-mixing deformationsin a model-controlled way. We then formulate FRW background dynamics including (i)standard matter/radiation, (ii) the scalar-type torsion/connection mode, (iii) a defect fluidsupplied by Paper III, and (optionally) (iv) a causal IR-vacuum closure term. Finally wepresent a data-ready linear perturbation closure in terms of Geff (k, a) and gravitational slipη(k, a), and we include the gravitational-wave friction parameter ν(a) = d ln M 2∗d ln a that controlsamplitude damping in modified Planck-mass backgrounds.