We consider the possibility that the dark energy is made up of two or more independent components, each having a different equation of state. We fit the model with supernova and gamma-ray burst data from recent observations, and use the Markov Chain Monte Carlo technique to estimate the allowed parameter regions. We also use various model selection criteria to compare the two-component model with the $\Lambda \mathrm{CDM}$, one-component dark energy model with static or variable $w$ (XCDM) and other multicomponent models. We find that the two-component models can give a reasonably good fit to the current data. For some data sets, and depending somewhat on the model selection criteria, the two-component model can give a better fit to the data than XCDM with static $w$ and XCDM with variable $w$ parametrized by $w=w_0+w_{a}z/(1+z)$.

• Received 22 August 2007

DOI:https://doi.org/10.1103/PhysRevD.76.123007