Unified CPT-Symmetric Cyclic Cosmology: From Timeless Geometric Foundations to Relaxation-Driven Dynamics with Explicit Bounce Transfer

Relaxation-Driven Cyclic Cosmology ( RDCC ) 2.0 This paper presents Relaxation-Driven Cyclic Cosmology (RDCC), a unified, minimal cosmological framework that integrates a timeless, globally CPT-symmetric geometric manifold as the ultraviolet (UV) foundation with a relaxation-driven effective field theory at infrared (IR) scales. Formulated within standard Einstein gravity and a single complex scalar field with a radiatively tilted double-well potential, RDCC resolves key cosmological puzzles, dark energy (as vacuum relaxation with w > -1), dark matter (as CPT-conjugate mirror baryons), baryon asymmetry, the arrow of time (as emergent sectoral projection), the initial singularity (via nonsingular bounce as CPT fixpoint), and entropy accumulation (via global conservation with cross-sector relaxation), without inflation, modified gravity, or extra degrees of freedom. The model is eternally cyclic, with multi-cycle stability ensured by gravitationally mediated relaxation (Γ ~ Gε²). It is background-degenerate with ΛCDM but predicts testable deviations, including stochastic gravitational-wave peaks at 10^{-3}–10^{-2} Hz (LISA), 21-cm modulations ~0.2–0.3%, ΔN_eff ~0.1–0.3, and percent-level suppression in fσ8(z) (Euclid/DESI/CMB-S4). This work offers a self-contained, falsifiable alternative to ΛCDM, emphasizing conceptual minimality and empirical verifiability. Euclid fσ₈ as a Probe of Relaxation-Driven Cyclic Cosmology (RDCC) - Appendix: https://zenodo.org/records/18646657 Related documents and the full RDCC ecosystem are available via Zenodo:https://zenodo.org/records/18204087 Michael [email protected]