Extremal principles in non-equilibrium thermodynamics

Extremal principles in non-equilibrium thermodynamics refer to certain fundamental postulates or criteria that dictate the behavior of physical systems away from equilibrium. These principles are extensions or analogs to more commonly known extremal principles in equilibrium thermodynamics, like the minimization of free energy. In non-equilibrium thermodynamics, the principles often relate to the maximization or minimization of certain quantities, such as entropy production, dissipation, or certain functionals related to thermodynamic potentials.