Abstract: We test the assumption that spacetime evolution in modern cosmology is autonomous, in the sense that residual deviations from ΛCDM expectations arise independently across observational domains and cosmic time. Using recent (2022–2026), publicly reported results from multiple conditionally independent probes of cosmic expansion, structure growth, large-scale anisotropy, bulk flows, and CMB–large-scale structure correlations, we examine whether the timing of reported deviations is consistent withstatistical independence.We introduce a model-agnostic, domain-normalized synchronization statistic that is insensitive to anomaly amplitude, sign, orphysical interpretation, and evaluate it using a sliding redshift window. Statistical significance is assessed using permutation-based null ensembles that preserve domain-specific anomaly counts while destroying temporal correlations.We find that multiple independent probes exhibit temporally coincident deviations at 𝑧 ≃ 0.05, 𝑧 ≃ 0.6, and 𝑧 ≃ 1.1, interleavedwith redshift intervals where broad consistency with ΛCDM is reported. Synchronization structures of comparable localizationand recurrence arise at the few-percent level in null realizations and remain stable across 0.1 ≲ 𝛿𝑧 ≲ 0.3.These results place statistical tension on the assumption that residual deviations arise independently in time across probes.Without proposing a specific alternative dynamical mechanism, we demonstrate that the assumption of spacetime autonomy can be treated as a falsifiable empirical hypothesis and that temporal structure provides a complementary diagnostic beyond anomaly amplitudes. - This manuscript is under consideration for publication in Monthly Notices of the Royal Astronomical Society.
Harshal Vikas Puranik (Fri,) studied this question.