FORK v5: A Dynamical Dark Energy Model Resolving the Hubble, JWST Early Galaxy, and S 8 S 8 Tensions

This study introduces FORK v5, a dynamical dark energy model that simultaneously addresses three major observational tensions in modern cosmology: the Hubble tension (5.2σ5.2σ), the JWST early galaxy anomaly, and the S8S8 tension (2.5σ2.5σ). The model uses the CPL parametrization for dark energy equation of state: w(z)=w0+waz1+zw(z)=w0+wa1+zz. A key feature of FORK v5 is its transition into a phantom energy regime (w<−1w<−1) at high redshifts (z≳2z≳2), which enhances early structure formation and predicts a greater abundance of massive galaxies at high zz, consistent with JWST observations. We perform extensive MCMC analyses using combined datasets including SH0ES Pantheon+, DESI Year 3 BAO, JWST CEERS/JADES galaxy mass functions, and Planck 2018 CMB power spectra. The best-fit parameters are: H0=71.23±1.82km s−1Mpc−1H0=71.23±1.82km s−1Mpc−1, Ωm=0.317±0.008Ωm=0.317±0.008, w0=−0.938±0.076w0=−0.938±0.076, wa=−0.207±0.115wa=−0.207±0.115. The model reduces the Hubble tension by over 90%, predicts 2.4 times more galaxies at z=12z=12 than ΛΛCDM, and lowers the S8S8 tension from 2.5σ2.5σ to 1.7σ1.7σ. The total χ2χ2 increase relative to ΛΛCDM is only +16.3 (p=0.089p=0.089), indicating no significant statistical preference against FORK v5. This work includes a physical interpretation via a scalar field Lagrangian, Jeans mass analysis in the phantom regime, and Bayesian model comparison. The study also highlights the collaborative role of AI in model building and parameter prediction. FORK v5 offers a testable, physically motivated alternative to ΛΛCDM and demonstrates how dynamical dark energy can resolve multiple cosmological crises at once. Keywords: dark energy, Hubble tension, JWST, S8S8 tension, cosmological parameters, phantom energy, structure formation, CPL parametrization, Bayesian analysis, cosmological simulations