Dynamical forces and the influence of an equation of state on gravitational collapse

Abstract

We investigate the equation of state (EoS) parameter on the collapse of a star undergoing dissipative collapse. The collapse starts from an initial static configuration described by the anisotropic generalisation of the Vaidya–Tikekar superdense model. The initial matter profile obeys a linear EoS and starts to radiate energy in the form of a radial heat flux as it leaves hydrostatic equilibrium. We study the evolution of the hydrostatic, gravitational, anisotropic and dissipative forces at play within the collapsing body via the dynamic Tolman–Oppenheimer–Volkoff equation. We show that the EoS parameter has a significant impact on the various forces which influences the outcome of gravitational collapse. The effect of the EoS parameter on the temperature profiles is also studied by employing a causal heat transport equation of Maxwell–Cattaneo form. Our investigation shows that the stiffness of the fluid which is related to its compressibility, is compromised in the presence of pressure anisotropy and heat flow.