Time Variable Cosmological Constant from Renormalization Group Equations

In this paper, a time variable cosmological constant (CC) from renormalization group equations (RGEs) is explored, where the renormalization scale $\mu^2=R^{-2}_{CC}=Max(\dot{H}+2H^2,-\dot{H})$ is taken. The cosmological parameters, such as dimensionless energy density, deceleration parameter and effective equation of state of CC etc, are derived. Also, the cosmic observational constraints are implemented to test the model's consistence. The results show that it is compatible with cosmic data. So, it would be a viable dark energy model.