The Origins of Inflation

Inflation would have started because of some vacuum energy of empty space, something like what Einstein described with his cosmological constant. But if this vacuum energy doesn't decrease as space expands, then why would inflation ever stop? Why wouldn't the universe just keep expanding at this huge exponential rate, making the development of stars and galaxies impossible? So when Alan Goose's original proposal for inflation was put forward, it was really challenging to figure out how this era might have come to an end. It turns out that inflation, as it was positive back in the 80s, makes fairly specific predictions.