Alladi Ramakrishnan Hall

Equations of state in the curved space-time of compact degenerate stars

Susobhan Mandal

IISER-Kolkata

In the study of spherical degenerate stars such as neutron stars, general relativistic effects are incorporated by using Tolman-Oppenheimer-Volkoff equations to describe their interior spacetime. However, the equations of states employed in such studies are invariably computed in flat spacetime. We show that the equation of states computed in the curved spacetime of these stars depends explicitly on the metric function. Further, we show that ignoring such metric-dependent gravitational time dilation effect leads one to grossly underestimate the mass limits of these compact stars. We also computed the equation of state for an ensemble of degenerate fermions by using the curved spacetime of a slowly rotating axially symmetric star where we show that the equation of state computed in such curved spacetime depends on the gravitational time dilation as well as on the dragging of inertial frames, unlike an equation of state computed in a globally flat spacetime.