2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/172430Exact time-dependent solutions of Einstein's gravitational field equation for a spherical mass moving with arbitrarily high constant velocity are derived and analyzed. The threshold conditions required for gravitational repulsion of particles at rest are determined as a function of source speed and field strength and particle position.3 pages, 3 figures; this version shows correspondence of exact 'antigravity' field, calculated from a metric first derived by Hartle, Thorne, and Price, with weak 'antigravity' fields calculated from retarded potentials in Ref. [2]; also adds impulse calculationGeneral Physicstext