The Einstein-Hilbert Lagrangian Density in a 2-dimensional Spacetime is an Exact Differential

摘要

Recently Kiriushcheva and Kuzmin claimed to have shown that theEinstein-Hilbert Lagrangian cannot be written in any coordinate gauge as anexact differential in a 2-dimensional spacetime. Since this is contrary toother statements on the subject found in the literature, as e.g., by Deser andJackiw, Jackiw, Grumiller, Kummer and Vassilevich it is necessary to do decidewho has reason. This is done in this paper in a very simply way using theClifford bundle formalism. In this version we added Section 18 which discussesa recent comment on our paper just posted by Kiriushcheva and Kuzmin.