Entropy and Variational Formulation of Relativistic Fluid Dynamics

Simplifying the representation of a dynamical system allows us to identify its genuine degrees of freedom and, consequently, the types of instabilities it can exhibit. In this work, we extend earlier variational analysis of classical non-barotropic flows to the more general relativistic non-barotropic case. Specifically, we present a new Eulerian variational formulation for relativistic non-barotropic flows, based on six functions.