The new theory challenges ideas earlier proposed by Hawking himself, particularly his previous view that the history of the universe has no boundary, that space existed without time before the Big Bang and therefore the universe has no beginning.
In their paper named "A Smooth Exit from Eternal Inflation" the physicists suggest that the universe is "globally finite and reasonably smooth."
"Now we're saying that there is a boundary in our past," co-author Thomas Hertog of the Belgian university KU Leven said in a press statement.
According to the theory, if the energy of eternal inflation existed before the Big Bang, then it might not have been entirely spent in our universe alone.
The new model doesn't eradicate the concept of multiple universes completely but it reduces the multiverse to a much smaller range of possible universes and trims them down to finite entities.
Hawking and Hertog theorize that there is a point where eternal inflation begins, and at that point it exists in a timeless state.
"When we trace the evolution of our universe backwards in time, at some point we arrive at the threshold of eternal inflation, where our familiar notion of time ceases to have any meaning," Hertog said.
"I think the key point about our model is not so much that constant density surfaces in the universe are finite, but rather that the variation in the multiverse is restricted."
The paper, published in the Journal of High Energy Physics, has been made free to download.
Stephen Hawking died this March in Cambridge at the age of 76, having suffered from a rare form of motor neuron disease since 1964.