Variable Chaplygin Gas: Constraints from Supernovae, BAO, Look Back
  Time, and GRBs
  We examine the variable Chaplygin gas (VCG) model with the aim of
establishing tight constraints by using type-Ia supernovae, lookback time
measurements, Baryon Acoustic Oscillations (BAO) and the Gamma Ray Bursts. We
report the parameter constraints obtained via statistical analysis of cosmic
observables namely, luminosity distance, BAO distance and lookback time
measurement
