Interpretations of Einstein’s equation differ primarily concerning whether E = mc entails that mass and energy are the same property of physical systems, and hence whether there is any sense in which mass is ever “converted” into energy (or vice versa). In this paper, I examine six interpretations of Einstein’s equation and argue that all but one fail to satisfy a minimal set of conditions that...

An obvious necessary condition for the existence of solutions to (1.1) is that the function K has to be positive somewhere. Moreover, there are the Kazdan-Warner obstructions [7, 16], which imply in particular, that a monotone function of the coordinate function X1 cannot be realized as the scalar curvature of a metric conformal to g0. Numerous studies have been made on equation (1.1) and its h...

le mouvement transversal de la locomotive ou des wagons , appele ie lacet, provient de deux causes principales: -la conicite des bandages -les irregularites de la voie dans ie plan horizontal. on se propose ici d'etudier la premiere cause , ce qui nous conduit a une equation differentielle non lineaire du deuxieme ordre. • l'equation en question est etudiee dans plusieurs cas difftten...

The rational solutions with as denominators powers of to the elliptic diophantine equation y x x are determined An idea of Yuri Bilu is applied which avoids Thue and Thue Mahler equations and deduces four term S unit equations with special properties that are solved by linear forms in real and p adic logarithms Introduction In a recent paper SW my colleague R J Stroeker and I determined the com...