ON HEAT-FLUX IN SIMPLE MEDIA

For any simple body we prove that there is an infinite number of mathematical functions which can be added to the response functional for the heat flux vector without affecting the balance laws, the entropy inequality, and the boundary conditions on the normal heat flux. The presence of this indetermination cannot be detected by usual physical experiments, namely by experiments in which cuts of the body are not taken into account. The maximal class of this indetermination is fully characterized in the thermoelastic case.