We propose a simple power-law parametrized quintessence model with time-varying equation of state and obtain corresponding quintessence potential of this model. This model is compared with Supernova Type Ia (SNIa) Gold sample data, size of baryonic acoustic peak from Sloan Digital Sky Survey (SDSS), the position of the acoustic peak from the CMB observations and structure formation from the 2dFGRS survey and put constrain on the parameters of model. The parameters from the best fit indicates that the equation of state of this model at the present time is $w_0=-{1.40}_{-0.65}^{+0.40}$ at $1\sigma$ confidence level. Finally we calculate the age of universe in this model and compare it with the age of old cosmological objects.

• Received 3 August 2006

DOI:https://doi.org/10.1103/PhysRevD.75.023512