Nonlinear Dynamics of a Dark Energy Model

We investigate a nonlinear equation of state arising in a phenomenological model of dark energy. The model is motivated by modifications to quintessence dynamics and leads to a non-linear differential equation for the Hubble parameter. We provide both approximate analytical methods and numerical solutions, demonstrating how nonlinearity alters the late-time acceleration of the Universe. The results suggest that deviations from linearized treatments can significantly modify the effective equation of state parameter at redshifts z < ۱, with potential implications for precision cosmology.

کلیدواژه ها:

Equation of state ، Cosmology ، Perturbation ، Numerical solution