The Active Gravitational Mass of a Heat Conducting Sphere Out of Hydrostatic Equilibrium

TL;DR

This paper derives an expression for the active gravitational mass of a heat-conducting relativistic sphere immediately after it leaves hydrostatic equilibrium, revealing how certain parameters influence its stability.

Contribution

It introduces a new formula for the active gravitational mass of a relativistic heat-conducting sphere out of equilibrium, highlighting the impact of system parameters on stability.

Findings

Larger characteristic parameters increase active gravitational mass in collapsing spheres.

Smaller active gravitational mass is associated with expanding spheres.

Parameter changes can enhance the instability of the system.

Abstract

We obtain an expression for the active gravitational mass of a relativistic heat conducting fluid, just after its departure from hydrostatic equilibrium, on a time scale of the order of relaxation time. It is shown that an increase of a characteristic parameter leads to larger (smaller) values of active gravitational mass of collapsing (expanding) spheres, enhacing thereby the instability of the system.