Relaxation-Driven Cyclic Cosmology (RDCC) v37. 0 A CPT-Symmetric, One-Parameter Framework with the First Prototype Global Fit What’s new in v37. 0? This release introduces the first *prototype global fit* of the RDCC relaxation parameter α, combining representative constraints from the scalar spectral tilt, dark radiation, large-scale structure, and upper bounds on the stochastic gravitational-wave background. The resulting posterior peaks at α ≈ 0. 016, in excellent agreement with the analytic estimate α ≈ (1 − nₛ) /2. This marks the first empirical anchoring of RDCC and demonstrates that its one-parameter prediction structure is compatible with current cosmological data. The full analysis is presented in the updated Companion V (v2. 0), including the new Section 6. 6 and revised Conclusion. --- Overview of the RDCC Framework Relaxation-Driven Cyclic Cosmology (RDCC) is a minimal and predictive cosmological framework based on a single structural postulate: the global quantum state of the Universe is a CPT eigenstate. This assumption leads to a bipartite Hilbert-space factorization into a visible sector and its CPT-conjugate mirror sector, coupled only through gravity and a unique dimension-six inter-sector operator. The operator generates a universal relaxation parameter α ~ 10⁻², whose infrared value controls all observable deviations from ΛCDM. A cuscuton-induced, ghost-free nonsingular bounce connects the contracting and expanding phases within the regime of validity of effective field theory. The global CPT structure ensures that the total entropy of the two-sector system is conserved, while each sector exhibits its own thermodynamic arrow of time. Gravity acts as the unique global interaction, producing an effective Newton constant Gₑff = GN / (1 + ρ₋/ρ₊) and giving rise to a gravitational shadow interpreted as dark matter. --- Correlated Predictions Across Ten Orders of Magnitude RDCC yields a tightly constrained, one-parameter correlation vector: • scalar spectral tilt: nₛ − 1 = −2α • dark-radiation excess: ΔNₑff ∼ α • percent-level growth-rate deviation: fσ₈ (z) • dark-matter to baryon ratio from gravitational shadowing • blue-tilted stochastic gravitational-wave background • log-periodic tensor oscillations from CPT interference across the bounce These signatures arise from a single infrared parameter and make RDCC sharply falsifiable. Any inconsistency among the predicted deviations rules out the framework, while detection of log-periodic gravitational-wave modulations—an unambiguous smoking-gun signature—would strongly support it. --- Cosmological Puzzles Addressed by RDCC RDCC provides unified structural explanations for several foundational problems: • Thermodynamic arrow of time: emerges as a sectoral property of a global CPT-symmetric state. • Initial singularity: resolved by a cuscuton-induced, ghost-free bounce. • Tolman entropy problem: avoided through global entropy conservation and minimal entropy at the bounce. • Dark matter: arises as a gravitational shadow of the CPT-conjugate sector, without new particle species. • Correlated deviations from ΛCDM: explained by the single relaxation parameter α. --- Contents of the v37. 0 Release • Updated flagship paper (RDCC v37. 0) with revised abstract referencing the global fit. • Companion V (v2. 0) including the new Section 6. 6, the prototype posterior, and an expanded Conclusion. • The RDCC framework is now empirically anchored and ready for precision testing with upcoming CMB, LSS, and gravitational-wave experiments such as CMB-S4, Euclid, LSST, LISA, and DECIGO. RDCC v37. 0 establishes the framework as a coherent, one-parameter cosmological model whose predictions span more than ten orders of magnitude in scale and are now directly confronted with data. Related documents and the full RDCC ecosystem are available via Zenodo: https: //zenodo. org/records/18204087 Michael Lehmannmi. lehmann@gmx. de
Michael Lehmann (Thu,) studied this question.