Abstract:
We present a generating functional which describes the equilibrium thermodynamic response of
a relativistic system to external sources. A variational principle gives rise to constraints on the
response parameters of relativistic hydrodynamics without making use of an entropy current. Our
method reproduces and extends results available in the literature. It also provides a technique for
efficiently computing n-point zero-frequency hydrodynamic correlation functions without the need
to solve the equations of hydrodynamics.
