The ${\mathrm{\Omega }}_{DE}-{\mathrm{\Omega }}_M$ Plane in Dark Energy Cosmology

The dark energy cosmology with the equation of state $w=constant$ is considered in this paper. The ${\mathrm{\Omega }}_{DE}-{\mathrm{\Omega }}_M$ plane has been used to study the present state and expansion history of the universe. Through the mathematical analysis, we give the theoretical constraint of cosmological parameters. Together with some observations such as the transition redshift from deceleration to acceleration, more precise constraint on cosmological parameters can be acquired.