Relaxation-Driven Cyclic Cosmology (RDCC) v1.19 A Minimal Eternal Model with Emergent Tilt, CPT-Conjugate Mirror Sector, and Testable Multi-Messenger Signatures

New in v1.19 (December 2025): - Unified perturbation framework linking large-scale (CMB) and small-scale (core-cusp, σ₈ tension) structure formation through bounce-generated fluctuations modulated by CPT-conjugate mirror duality.- Schematic effective density contrast illustrating anti-correlated perturbations on small scales.- Multi-messenger test roadmap with concrete observational timeline (Planck/DESI/Euclid, JWST/Roman, LISA, SKA).- Refined discussion emphasising the model's single emergent parameter (ε) and correlated, falsifiable predictions. RDCC remains strictly minimalist: one field, standard gravity, no new particles, no modified gravity, no inflation required. Key solved puzzles: evolving dark energy (resolving Hubble tension), dark matter (mirror sector), baryon asymmetry, DM/baryon ratio ≈5.4, neutrino masses as CPT effects, nonsingular cosmology (bounce + black holes as mini-bounces). Primary testable predictions:- Order-10% late-time ISW excess (low-ℓ CMB)- Distinctive peaked stochastic GW background (f_peak ~ 10^{-3}–10^{-2} Hz, LISA)- Small-scale power suppression and core-cusp solution- 21-cm signal modulations (high-z, SKA) Previous version: v1.18 (DOI: 10.5281/zenodo.18053680) E-Mail: [email protected]