Stephen Hawking's final research paper suggests that the universe may be one of many similar to our own, resolving a cosmic paradox of the late British physicist's own making.
The paper submitted to the Journal of High-Energy Physics, 10 days before Hawking died on March 14, also points a way forward for astronomers to find evidence of the existence of parallel universes.
In the 1980s, Hawking, along with US physicist James Hartle developed a new idea about the beginning of the universe, BBC News reported.
This resolved a difficulty with Einstein's theory that suggested that the universe began nearly 14 billion years ago but said nothing about how it began.
The Hartle-Hawking idea used a theory called quantum mechanics to explain how the universe arose from nothingness.
As scientists analysed the idea, it carried with it the implication that the Big Bang would create not just one universe - but an endless supply.
Some, according to the theory, would be very like our own universe, while others would be subtly different.
Hawking collaborated with Thomas Hertog, a professor at KU Leuven in Belgium, to try to resolve this paradox.
"Neither Stephen nor I were happy with that scenario," Hertog said.
Hawking's final paper has solved the puzzle by drawing on new mathematical techniques developed to study another branch of physics called string theory.
The new assessment of the Hartle-Hawking theory in the latest paper has restored order to a hitherto chaotic multiverse.
The analysis suggests that there can only be universes that have the same laws of physics as our own, according to the paper.
According to Hertog, these ideas may be of real help to physicists as they develop a more complete theory of how the universe came into being.