Particles in Friedmann and Einstein-Strauss universes

Expressions are given for the energy and momentum of a free particle in a Friedmann universe and in an Einstein-Strauss universe. Special attention is given to the determination of the conserved quantities for the particle motion. The necessary conditions are given for a particle injected into a Schwarzschild geometry from an expanding open, closed or flat dust-filled Friedmann universe, matched to that geometry, to find itself in a bound orbit. (orig.)