Gravitational waves for variable modified Chaplygin gas and some parametrizations of dark energy in the background of FRW universe

Abstract

In this work, we assume the Friedmann–Robertson–Walker (FRW) model of the non-flat Universe composed of dark matter and dark energy. Here the dark energy components are variable modified Chaplygin gas (VMCG) and some well-known parametrizations (models I–XIII). We assume that the dark matter and the dark energy are separately conserved. So the solutions of energy densities of the dark matter and dark energy are obtained in terms of observable quantities and the parameters associated with the models. Next we obtain the evolution equation for gravitational wave in the background of FRW Universe. Due to numerical analysis, we obtain the wave curve for VMCG and other dark energy models (models I–XIII). We investigate the power spectrum of the gravitational wave for VMCG and parametrizations of dark energy models I–XIII in diagrammatically.