CPT-Symmetric Cyclic Cosmology ( RDCC ) 2.4: From Timeless Geometric Foundations to Relaxation-Driven Dynamics with Explicit Bounce Transfer

Relaxation-Driven Cyclic Cosmology (RDCC) 2. 4 Relaxation-Driven Cyclic Cosmology (RDCC) is a minimal, nonsingular, eternally cyclic cosmological framework formulated within standard Einstein gravity supplemented by controlled ultraviolet corrections at the bounce and a single complex scalar field. The theory is globally CPT-symmetric and fundamentally timeless: time, entropy production, and causal structure arise only as sectoral, thermodynamic projections of an underlying CPT-invariant two-dimensional warped-product manifold. The model unifies dark energy (as vacuum relaxation driven by a radiatively generated tilt), dark matter (as CPT-conjugate mirror-sector baryons), baryon asymmetry, the arrow of time, the initial singularity problem, and entropy accumulation within a single structural assumption, the absence of a globally preferred time direction. It requires neither inflation, modified gravity, nor additional degrees of freedom beyond those already present in the Standard Model plus its CPT-mirror realization. Key predictions include a characteristic stochastic gravitational-wave background peaked at f ≈ 10^-3–10^-2 Hz (testable with LISA), percent-level corrections to fσ₈ (z), oscillatory features in the global 21-cm signal at the 0. 2–0. 3 % level, and a small contribution ΔNₑff ≈ 0. 1–0. 3. The framework is fully background-degenerate with ΛCDM while providing a self-contained, falsifiable alternative that resolves the Tolman entropy problem through gravitationally mediated cross-sector relaxation. This preprint (February 2026) presents the complete theoretical framework, including the rigorous ultraviolet geometric foundation, the effective 4D projection, background and perturbation dynamics, and quantitative observational signatures. RDCC eliminates at a stroke the initial singularity, the need for inflation, the cosmological constant problem, the dark-matter and dark-energy puzzles, the arrow of time, the Tolman entropy problem, initial-condition fine-tuning, baryon asymmetry, and the global time-direction paradigm, all without new fields, modified gravity, or inflation. The model is minimal, internally consistent, and falsifiable with upcoming large-scale structure surveys such as Euclid, DESI, and CMB-S4. Related documents and the full RDCC ecosystem are available via Zenodo: https: //zenodo. org/records/18204087 Author: Michael Lehmannmi. lehmann@gmx. de