Cosmological analogies, Lagrangians, and symmetries for convective–radiative heat transfer

A formal analogy between the Friedmann equation of relativistic cosmology and models of convective–radiative cooling/heating of a body (including Newton’s, Dulong–Petit’s, Newton–Stefan’s laws, and a generalization) is discussed. The analogy highlights Lagrangians, symmetries, and mathematical properties of the solutions of these cooling laws