Behaviour of gravastar model in mimetic gravity

Abstract In this paper, we have constructed a unique gravastar model proposed by Mazur and Mottola in the spherically symmetric stellar system under the mimetic gravitational framework with the presence of isotropic fluid source. The gravastar consists of three regions namely the interior, the shell and the exterior. In the interior region, the gravastar follows the equation of state(EoS) p = − ρ . Here we have found the non-singular solutions. The next region is a thin shell of ultra-relativistic stiff fluid having EoS p = ρ in which we have investigated several physical properties such as the proper length, energy and entropy and it is observed that all these properties are increasing with the increase in thickness of the shell. The exterior of the gravastar has been described as the Schwarzschild type. We found the matching between the surfaces of interior and exterior of the gravastar. Using the junction conditions, we have obtained the surface energy density and surface pressure which are found to be decreasing with the thickness of the shell. Moreover our gravastar model is found to be stable as we observe from the speed of sound and the entropy maximization technique. Our derived model is in accordance with the works also. Finally we have developed a stable gravastar model without singularities and devoid of any incompleteness in classical black hole theory.