By merging two seemingly conflicting theories, Laura Mersini-Houghton has mathematically proven black holes can never come into being in the first place. Black holes are thought to be the densist matter in the universe.
Mersini-Houghton’s theory combine Hawking’s radiation theory with a fundamental law of quantum theory that states no information from the universe can ever disappear.
Mersini-Houghton agrees with Hawking in that a star’s collapse gives off radiation; but by giving off radiation, she said the star also sheds mass to the point that it no longer has the density to become a black hole.
A star collapsing gravitationally into a black hole emits a flux of radiation, knowns as Hawking radiation. When the initial state of a quantum field on the background of the star, is placed in the Unruh vacuum in the far past, then Hawking radiation corresponds to a flux of positive energy radiation travelling outwards to future infinity. The evaporation of the collapsing star can be equivalently described as a negative energy flux of radiation travelling radially inwards towards the center of the star. Here, we are interested in the evolution of the star during its collapse. Thus we include the backreaction of the negative energy Hawking flux in the interior geometry of the collapsing star and solve the full 4-dimensional Einstein and hydrodynamical equations numerically. We find that Hawking radiation emitted just before the star passes through its Schwarzschild radius slows down the collapse of the star and substantially reduces its mass thus the star bounces before reaching the horizon. The area radius starts increasing after the bounce. Beyond this point our program breaks down due to shell crossing. We find that the star stops collapsing at a finite radius larger than its horizon, turns around and its core explodes. This study provides a more realistic investigation of the backreaction of Hawking radiation on the collapsing star