A Minimal Effective Saturation Cosmology with a Nonsingular Bounce and Representative Inflationary Continuation

I develop the cosmological predictions of an effective theory of asymptotic density saturation (FTAR), consistent with higher-curvature corrections to Einstein gravity expected from quantum effects. A dynamically generated saturation density ρsat arising from conformal-trace-anomaly-induced renormalization group (RG) flow provides a mechanism for singularity avoidance within the effective description and governs the large-scale evolution of the Universe. Starting from the one-loop effective action for the conformal mode of the metric, I derive: (i) a nonsingular cosmological bounce replacing the Big Bang singularity; (ii) a phase of hilltop-type quasi-de Sitter inflation driven by saturation dynamics without an additional inflaton field; (iii) a primordial perturbation spectrum with spectral index ns≈1−2/N≈0.964 (slow-roll estimate); (iv) a suppression of primordial power at the largest angular scales from the finite bounce duration; (v) reheating from geometric relaxation via universal trace coupling; (vi) a mechanism for stable Planck-mass remnant dark matter; and (vii) an estimate of the residual vacuum energy from incomplete RG relaxation. Numerical integration of the full FTAR field equations yields a tensor-to-scalar ratio r=1.89×10−4, confirming the strongly hilltop character of the inflationary phase. The Einstein-frame scalar-tensor formulation is shown to be mathematically equivalent to a Jordan-frame f(R) geometric interpretation, linking the saturation mechanism to R2Starobinsky-like gravity at intermediate curvatures. Version History / Changelog (v5.0): Refined the abstract terminology to strictly reflect an Effective Field Theory (EFT) approach. Adjusted the wording regarding the cosmological bounce (from fundamental derivation to effective yield) to prevent overclaiming and align with QFT-in-curved-spacetime standards. Added explicit "phenomenological" caveats to the residual vacuum energy estimates (point vii). Synchronized the methodological stance, parameters (r=1.89×10−4), and cross-references with the finalized companion papers (Paper I and Paper III).