ENERGY AND HEAT-FLUX

The total energy in a sphere containing an isotropic shear-free conduc ting heat fluid is studied in the frame of a spherically symmetric met ric. Firstly, we examine the role played by the heat flux. Secondly, w e point out the contribution to the energy by the Weyl tensor. We obta in different formulas for the total energy, and those formulas are sho wn to be equivalent. We derive the general solution for a conformally flat spacetime, and give an example for a nonconformally flat spacetim e.