Finally we come to the type of fluid which will be of
most interest to us. A perfect fluid in Special Relativity is defined to be a fluid that has no heat
conduction in the MCRF. It is the generalization of the ideal gas
in ordinary thermodynamics. In the MCRF the components of
are
It is easy to show that in a general frame we have [ Assignment 4 ]:
This is the energy- momentum tensor of a perfect
fluid .