Dynamic Evolution Theory

Abstract The ΛCDM model, while remarkably successful, faces persistent tensions that may signal new physics beyond the standard cosmological paradigm. We introduce the Dynamic Evolution Theory (DET), a unified scalar-tensor framework that addresses both the Hubble tension (H0) and the structure-growth tension (S8) through a single, multi-stage scalar field evolution. In the early Universe, finite-temperature corrections to an axion-monodromy potential trigger a first-order phase transition near matter–radiation equality. The ensuing early dark energy (EDE) episode briefly contributes ∼ 10% of the cosmic energy budget, boosting the pre-recombination expansion rate and reducing the sound horizon by ∼ 3%. This shift raises the CMB-inferred Hubble constant to H0 = 73.2 ± 1.2 km s−1 Mpc−1 , in excellent agreement with local measurements. At late times, a non-minimal conformal coupling Ω(ϕ) = 1 + ξϕ2/M2 Pl modifies the effective gravitational strength, suppressing the growth of structure. The resulting S8 = 0.752 ± 0.012 resolves the longstanding tension between Planck and weak-lensing surveys while satisfying the GW170817 constraint cgw = c and passing Solar System tests via a Chameleon screening mechanism. We confront DET with the latest observational data, including Planck 2018 CMB, DESI 2024 BAO, and Pantheon+ supernovae, and find a ∆χ 2 = −24.8 relative to ΛCDM. Bayesian model comparison yields a Bayes factor ln B = 4.6, indicating strong evidence in favor of DET. The theory makes sharp, testable predictions for upcoming facilities: a 2–5% enhancement in the weak-lensing power spectrum with Euclid, a distinctive absorption feature in the global 21-cm signal with SKA, a ∼ 12% enhancement of the integrated Sachs–Wolfe effect with CMB-S4, and precise agreement with DESI BAO measurements. By connecting early- and late-time physics through a single dynamical degree of freedom, DET offers a compelling, observationally driven extension of the standard cosmological model.