COMMENTS ON THE EXISTENCE OF HAMILTONIAN PRINCIPLES FOR NONSELF-ADJOINT OPERATORS

The thermodynamic transport equations contain the first time derivativ e, a non self-adjoint operator, which makes it impossible to derive th em from Hamilton's variational principle. However, introducing new bas ic fields which generate measurable properties in the same way as the potentials in other held theories, the complete Hamilton Lagrange form alism may be established. This fact ostensibly surpasses Finlayson's w ork where special restrictions for classical variational principles ar e given. We point out that although these restrictions seem to preclud e the construction of a variational scheme for the transport equations , a correct interpretation of these facts permits to solve this appare nt paradox. The Onsager reciprocal relations play a central role in th e compatibility between these two apparent opposite views.