Fractional action dynamics in bianchi IX cosmology: Suppression of mixmaster chaos and Early-Time isotropization without inflation

In this paper, we investigate the role of fractional action cosmology (FAC) in the early-time dynamics of the Bianchi IX (Mixmaster) universe. The inclusion of a fractional power of the cosmic time parameter modifies the Einstein–Hilbert action and introduces a natural, nonlocal damping term in the anisotropic evolution equations. We show that this fractional damping suppresses the classical Belinskii–Khalatnikov–Lifshitz (BKL) chaotic oscillations that characterize the standard General Relativity approach to the cosmological singularity. Using numerical integration of the fractional Bianchi IX system, we reconstruct the evolution of scale factors, phase-space trajectories, and the dimensionless shear parameter [Formula: see text] for various fractional indices [Formula: see text]. Our results demonstrate that for [Formula: see text], the shear decays much more rapidly than in General Relativity, enabling the universe to become isotropic well before recombination without invoking an inflationary phase. Multi-[Formula: see text] shear evolution curves further show that a wide range of fractional parameters yield [Formula: see text] below the CMB anisotropy bound. These results suggest that fractional action cosmology provides a robust alternative to inflation for resolving the isotropy problem and significantly alters the standard picture of the Mixmaster approach to the singularity.