It is entirely different. The galaxies are not falling towards the edge of the universe due to any force. The galaxy-clusters move outwards and their speeds increase. The energy required for this comes from the internal energy of the clusters. The internal energy includes the individual speeds of the galaxies, the individual speeds of the stars and other masses in it and the internal energies of these masses. So as the galaxies move outwards, the internal energies of masses change into external energies. The observable evidence is fusion in stars, where energy is released. The whole of the energy thus released is not radiated; it actually goes to increase the speed of the star; this increase in energy (speed)of the star is transferred to the galaxy, and from there to the cluster. This will continue until the speed of the cluster can no more increase. So the expansion stops. That state is a potential state where the speeds of the clusters are very high, but internal energies very low. So the system starts contracting so as to reach the normal state (speed and internal energy has a normal ratio). But the change from that 'potential state'to the 'normal state' takes it to the other extreme where the internal energies are high, and speed low. So it again expands. In the absence of any external force acting on the universes. it oscillates between the two extremes, and thus remains pulsating.