2009/06/11 by Bel, Ll., Martin-Martin, J.
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.0906.2170
The concept of \it active gravitational mass, its definition and its relation with the sources of a gravitational field, was clearly established by Tolman in 1934. On the contrary, and surprisingly in our opinion, the concept of \it proper mass has remained obscure in General relativity. We compare a new definition to an apparent more obvious one and discuss how each choice modifies the ratio of active to proper gravitational mass.