Indian physics trio rewrites singularity, death of stars

A year after they bonded over physics at a Jaipur conference, the trio has proposed that the dramatic end of such a dying star is explosively different from theories that classical physics has stood by since Einstein.

‘‘It’s an exciting development at the very foundation of all of black hole physics,’’ says Joshi. ‘‘Our test predicts that a dying, shrinking star of a mass four or five times more than the Sun, goes dim. In its last microseconds, it throws away all its matter in an explosive burst that can be observed like a flash or fireball.’’

That’s not how Einstein’s classical theories described it. Rather, the general theory of relativity predicts that these stars, instead of exploding, would turn into a naked singularity—a very dense region where a spoonful of matter weighs infinitely heavy.

But when the team applied laws of quantum gravity to Einstein’s model, there was no naked singularity. ‘‘We had not anticipated a star burst of radiation,’’ says Joshi. ‘‘We have not solved the problem or got details of the emissions, which could be super-energy cosmic rays or gamma rays. But what we predict can be a good test for quantum gravity.’’ This proposed experimental test for quantum gravity is the first step to unify the forces of gravity that rule the universe and the quantum forces that govern the atomic world.

‘‘The team claims the phenomenon will be observable, that makes it exciting,’’ says TIFR Director Shobo Bhattacharya. ‘‘Understanding collapsing stars is part of frontier physics.’’