A Six Birds' Eye View of Dark Energy: Closure, Route Mismatch, and Audits for Apparent Acceleration

Empirical cosmology infers late-time acceleration by fitting homogeneous FLRW models to data products that are coarse-grained summaries of an inhomogeneous universe. This makes it hard to distinguish a fundamental component from a closure correction induced by coarse-graining. We apply Six Birds Theory (SBT) to treat cosmological modeling as a closure package with a lens (what is retained), a completion (how discarded structure is filled in), and audits (tests of dynamical coherence under evolution). We implement a minimal computational API for lenses, completions, packaging operators, idempotence defects, and route mismatch, together with provenance-tracked run bundles and posterior-predictive cross-probe audits. In calibrated toy systems, route mismatch is consistent with zero in a linear control regime and becomes strictly positive when nonlinearity is introduced. In a patch-expansion proxy, homogeneous control yields Q(t) approximately 0, whereas heterogeneous initial conditions produce a positive acceleration proxy (Q_peak approximately 1.74) and domain acceleration greater than 0 for about 99% of late-time samples. Using synthetic distance–redshift data from a null-Lambda heterogeneous generator, homogeneous LambdaCDM fitting recovers Omega_Lambda about 0.60. A heterogeneity-proxy rewrite term matches LambdaCDM fit quality and improves held-out prediction of a heterogeneity proxy by about 100x in RMSE. We also demonstrate the same provenance and audit pipeline on public DES SN 5-year and DES Y6 BAO releases.