A covariant action principle for dissipative fluid dynamics: From formalism to fundamental physics

Understand

We present a new variational framework for dissipative general relativistic fluid dynamics.

• The model extends the convective variational principle for multi-fluid systems to account for a range of dissipation channels.
• The key ingredients in the construction are i) the use of a lower dimensional matter space for each fluid component, and ii) an extended functional dependence for the associated volume forms.
• In an effort to make the concepts clear, the formalism is developed in steps with the model example of matter coupled to heat considered at each level.