Nonunitary Newtonian Gravity Makes Semiclassical Gravity Viable for All Practical Purposes

Abstract

Semiclassical Gravity replaces the energy momentum tensor $T_{\mu \nu}$ with its expectation value $\langle T_{\mu \nu}\rangle$ in Einstein equations, this making the Einstein tensor $G_{\mu \nu}$ a classical variable thus avoiding the quantization of the gravitational field. Jointly with the Copenhagen interpretation of QM, Semiclassical Gravity gives rise to cases of Superluminal Communication. It is shown in a specific instance that a model of Nonunitary Newtonian Gravity avoids Superluminal Communication by decohering linear superpositions of macroscopically distinct states, namely Schrodinger's cats.