Variable Chaplygin gas: Constraints from CMBR and SNe Ia

We constrain the parameters of the variable Chaplygin gas model, using the location of peaks of the CMBR spectrum and the SNe Ia "gold" data set. The equation of state of the model is P = -A(a)/rho, where A(a) = A(o)a(-n) is a positive function of the cosmological scale factor a, A(o) and n being constants. The variable Chaplygin gas interpolates from the dust-dominated era to the quintessence dominated era. The model is found to be compatible with current type Ia supernovae data and the location of the first peak if the values of Omega(m) and n lie in the interval [0.017,0.117] and [-1.3, 2.6], respectively.