On the energy and entropy of Einstein's closed universe

Introduction. - In a preceding article,(1) two principles have been proposed, expressed in a form valid for all sets of coordinates which seem suitable to serve as the analogues in general relativity for the first and second laws of thermodynamics. It is the purpose of the present article to apply these principles to the Einstein closed universe, regarded as fled with a perfect fluid, so as to obtain expressions which may be taken as representing the energy and entropy of this universe.