Generalized Chaplygin gas and CMBR constraints

M. C. Bento, O. Bertolami, A. A. Sen

Published 2002-10-21, updated 2002-10-25Version 2

We study the dependence of the location of the Cosmic Microwave Background Radiation (CMBR) peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by $p = - A/\rho^{\alpha}$, where $A$ is a positive constant and $0 < \alpha \le 1$. We find, in particular, that observational data arising from Archeops for the location of the first peak, BOOMERANG for the location of the third peak, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the $\alpha = 1$ Chaplygin case and the $\Lambda$CDM model.