London: Stephen Hawking's final scientific paper – which was completed days before the British physicist's death – has been written and posted online by his colleagues at Cambridge and Harvard universities.
The paper named Black Hole Entropy and Soft Hair, tackles with what happens to information when it falls into a blackhole, a problem that theoretical physicists refer to as 'the information paradox', said researchers from Cambridge University in the UK.
It was completed in the days before Hawking's death in March, and has now been written up by his colleagues at and posted online, 'The Guardian' reported.
According to co-author Malcolm Perry, a professor at Cambridge University, the information paradox was "at the centre of Hawking's life" for over 40 years.
In 1915, Albert Einstein published his theory of general relativity, which described how gravity arises from the spacetime-bending effects of matter.
However, Einstein made important predictions about black holes too, notably that a black hole can be completely defined by only three features: its mass, charge, and spin.
Nearly 60 years later, Hawking argued that black holes also have a temperature. Since hot objects lose heat into space, the ultimate fate of a black hole is to evaporate out of existence.
However, the rules of the quantum world dictate that information is never lost. So what happens to all the information contained in an object when it tumbles into a black hole.
In the latest paper, Hawking and his colleagues showed how some of the information may be preserved.
Days before Hawking died, Perry was at Harvard working on the paper with colleagues. He was not aware how ill Hawking was and called to give the physicist an update.
It may have been the last scientific exchange Hawking had.
"It was very difficult for Stephen to communicate and I was put on a loudspeaker to explain where we had got to. When I explained it, he simply produced an enormous smile. I told him we'd got somewhere. He knew the final result," he said.