Does the charge of a body reduce its gravitational field?

V. Hushwater

Published 2001-03-01, updated 2010-06-02Version 2

One can get the impression from the Reissner-Nordstrom solution of Einstein's equations that the charge of a body reduces its gravitational field. This looks surprising since the energy of the electrostatic field surrounding a charged body, must contribute positively, as an additional, "electromagnetic mass", to the gravitational field produced by the body. We resolve this puzzle by showing that the mass M in the Reissner-Nordstrom solution is not the "bare mass" of the body, but its "renormalized mass". I. e. M, in addition to the bare mass, includes the total electromagnetic mass of the body. But at finite distances from the body only a part of the electromagnetic mass contributes to the gravitational field. That is why the gravity of a charged body is determined by the quantity smaller than M.