Narrow Results

The study of cosmic expansion history and the late time cosmic acceleration from observational data depends on the nuisance parameters associated with the data. For example, the absolute peak magnitude of type Ia supernova associated with the type Ia supernova observations and the comoving sound horizon at the baryon drag epoch associated with baryon acoustic oscillation observations are two nuisance parameters. The nuisance parameters associated with the gamma-ray bursts data are also considered. These nuisance parameters are constrained by combining the cosmological observations using the Gaussian process regression method with minimal model dependence. The bounds obtained in this method can be used as the prior for the data analysis while considering the observational data accordingly. Along with these nuisance parameters, the cosmic curvature density parameter is also constrained simultaneously. We find that the constraints on the cosmic curvature density parameter show no significant deviations from a flat Universe.