Taijitu Relaxation Cosmology (TRC) v6.0 A Minimal Eternal Model with Emergent Tilt, CPT-Conjugate Mirror Sector, and Testable Multi-Messenger Signatures

Taijitu Relaxation Cosmology (TRC) v6.0 is a minimalist eternal cosmological framework based on standard Einstein gravity and a single complex scalar field Φ in a softly tilted double-well potential. The emergent tilt ε (~10⁻³–10⁻²) arises from Coleman-Weinberg radiative corrections. TRC unifies dark energy (vacuum relaxation), dark matter (strict CPT-conjugate mirror sector), baryon asymmetry, neutrino masses, primordial perturbations, Hubble tension resolution, and nonsingular cyclic evolution without inflation, modified gravity, or additional fields. The cosmological bounce is identified as an unavoidable CPT-fixpoint of the global symmetry, where an effective description induces a brief interval of ρ + p < 0 driven by phase dynamics near vanishing potential. Entropy is strictly local to time-oriented sectors; no accumulation across cycles occurs. Key distinguishing predictions include a peaked stochastic gravitational wave background (LISA-detectable at 10⁻³–10⁻² Hz), mild small-scale power suppression addressing core-cusp and σ₈ issues, and characteristic 21-cm modulations. TRC is presented as a structural framework clarifying the conditions under which time-oriented cosmology emerges in a globally CPT-symmetric spacetime. Future work will focus on numerical evolution and effective field theory analysis near the fixpoint. Keywords: cyclic cosmology, bounce cosmology, CPT symmetry, mirror sector, dark energy, dark matter, gravitational waves, Hubble tension, primordial perturbations, multi-messenger astronomy. Independent research by Michael Lehmann. E-Mail: mi.lehmann@gmx.de Previous versions: v5.0: https://zenodo.org/records/17944963 v4.0: https://zenodo.org/records/17944963v3.0: https://zenodo.org/records/17917109v2.0: https://zenodo.org/records/17842042