Why Dark Matter Is Five Times Baryonic Matter: A CPT-Symmetric Two-Sector Cosmology, TDEC 2.1

Why Dark Matter Is Five Times Baryonic Matter: A CPT-Symmetric Two-Sector Cosmology, TDEC 2. 1, is a minimal, nonsingular and fundamentally timeless cosmological framework formulated within standard Einstein gravity and a single complex scalar field. The theory is globally CPT-symmetric. Time, entropy production, causal structure, the arrow of time, dark energy (as slow vacuum relaxation with w > −1), dark matter (as CPT-conjugate mirror-sector baryons) and the baryon asymmetry all emerge as sectoral thermodynamic projections of a single underlying static, Bell-like entangled spacetime geometry defined on a two-dimensional warped-product manifold. No inflation, no modified gravity, no ultraviolet bounce corrections and no additional degrees of freedom are required. The two sectors remain permanently entangled in a static equilibrium, stabilised by a weak gravitationally mediated relaxation parameter α that acts as a continuous dissipative stabiliser (analogous to weak monitoring that preserves a Bell state). The framework yields concrete, falsifiable predictions including a characteristic stochastic gravitational-wave background at 10^-3–10^-2 Hz, 21-cm modulations at the 0. 2–0. 3 % level, deviations ΔNₑff ∼ 0. 1–0. 3, and percent-level corrections to fσ8 (z). It constitutes a highly testable, self-contained alternative to ΛCDM in which the entire cosmic evolution is the asymptotic equilibrium state of a single timeless, maximally entangled geometric structure. Full derivation of the UV geometry, effective field theory, background dynamics, linear and nonlinear perturbations, mirror-sector phenomenology and quantitative observational forecasts are included. Michael Lehmann @mi. lehmann@gmx. de