Relativistic thermodynamics with angular momentum and its application to blackbody radiation

The equilibrium state of an isolated system is characterized by its conserved quantities. The total energy and particle number are usually taken into account in conventional thermodynamics, however, angular momentum is often overlooked. In the present paper, relativistic thermodynamics has been generalized to include angular momentum as a thermodynamical parameter. The resulting relativistic equilibrium has a remarkable difference from the one without angular momentum: a rotating body has a global temperature that is different from the local temperatures. Blackbody radiation from a rotating body is calculated as an example of applications of this global temperature.