Variable Chaplygin Gas: Constraints from Supernovae and Gravitational Wave Merger Events

We investigate the cosmological constraints on the Variable Chaplygin gas model from the latest observational data: SCP Union 2.1 compilation dataset of Type Ia supernovae (SNe Ia), Pantheon sample of SNe Ia, and GWTC-3 of gravitational wave merger events. The Variable Chaplygin gas is a model of interacting dark matter and dark energy, which interpolates from a dust-dominated era to a quintessence- dominated era. The Variable Chaplygin gas model is shown to be compatible with Type Ia Supernovae and gravitational merger data. We have obtained tighter constraints on cosmological parameters B s and n , using the Pantheon sample. By using the Markov chain Monte Carlo (MCMC) method on the Pantheon sample, we obtain B s =0.108 ± 0.034, n=1.157 ± 0.513 and H 0 =70.020 ± 0.407 and on GWTC-3, we obtain B s =0.130 ± 0.076, n=0.897 ± 1.182 and H 0 =69.838 ± 3.007.