Prompted by the recent Maxima -1 and Boomerang -98 measurements of the cosmic microwave background ( CMB ) anisotropy power spectrum , and motivated by the results from the observation of high-redshift Type Ia supernovae , we investigate CMB anisotropies in quintessence models in order to characterize the nature of the dark energy today .
We perform a Bayesian likelihood analysis , using the Maxima -1 and Boomerang -98 published bandpowers , in combination with COBE/DMR , to explore the space of quintessence parameters : the quintessence energy density \Omega _ { \phi } and equation of state w _ { \phi } .
We restrict our analysis to flat , scale-invariant , inflationary adiabatic models .
We find that this simple class of inflationary models , with a quintessence component { { { { \Omega _ { \phi } \mathrel { \mathchoice { \lower 3.6 pt \vbox { \halign { \cr } $ \displaystyle% \hfil < $ \cr$ \displaystyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { \halign { \cr } $% \textstyle \hfil < $ \cr$ \textstyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { \halign { \cr } $% \scriptstyle \hfil < $ \cr$ \scriptstyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { \halign { \cr% } $ \scriptscriptstyle \hfil < $ \cr$ \scriptscriptstyle \hfil \sim$ } } } } 0.7 , { { { { -1 \leq w _ { \phi } \mathrel { \mathchoice { \lower 3.6 pt \vbox { \halign { \cr } $% \displaystyle \hfil < $ \cr$ \displaystyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { \halign { % \cr } $ \textstyle \hfil < $ \cr$ \textstyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { \halign { % \cr } $ \scriptstyle \hfil < $ \cr$ \scriptstyle \hfil \sim$ } } } { \lower 3.6 pt \vbox { % \halign { \cr } $ \scriptscriptstyle \hfil < $ \cr$ \scriptscriptstyle \hfil \sim$ } } } } -0.5 , is in good agreement with the data .
Within the assumptions of our analysis , pure quintessence models seem to be slightly favored , although the simple cosmological constant scenario is consistent with the data .