FYI -- http://beta.slashdot.org/story/207637 Black holes, the stellar phenomena that continue to capture the imagination of scientists and science fiction authors, may not actually exist. According to a paper published by physics professor Laura Mersini-Houghton at the University of North Carolina and Mathematics Professor Harald Pfeiffer of the University of Toronto, as a collapsing star emits Hawking radiation, it also sheds mass at a rate that suggests it no longer has the density necessary to become a black hole  the singularity and event horizon never form. While the arXiv paper with the exact solution has not yet been peer reviewed, the preceding paper by Mersini-Houghton with the approximate solutions was published in Physics Letters B. "I'm still not over the shock," said Mersini-Houghton. "We've been studying this problem for a more than 50 years and this solution gives us a lot to think about... Physicists have been trying to merge these two theories  Einstein's theory of gravity and quantum mechanics  for decades, but this scenario brings these two theories together, into harmony." ------------------ http://arxiv.org/abs/1409.1837 Back-reaction of the Hawking radiation flux on a gravitationally collapsing star II: Fireworks instead of firewalls 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 reach ing 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, that was first presented in [1]. http://www.sciencedirect.com/science/article/pii/S0370269314006686/pdf?md5=b... Backreaction of Hawking radiation on a gravitationally collapsing star I: Black holes? Particle creation leading to Hawking radiation is produced by the changing gravitational field of the collapsing star. The two main initial conditions in the far past placed on the quantum field from which particles arise, are the HartleÂHawking vacuum and the Unruh vacuum. The former leads to a time-symmetric thermal bath of radiation, while the latter to a flux of radiation coming out of the collapsing star. The energy of Hawking radiation in the interior of the collapsing star is negative and equal in magnitude to its value at future infinity. This work investigates the backreaction of Hawking radiation on the interior of a gravitationally collapsing star, in a HartleÂHawking initial vacuum. It shows that due to the negative energy Hawking radiation in the interior, the collapse of the star stops at a finite radius, before the singularity and the event horizon of a black hole have a chance to form. That is, the star bounces instead of collapsing to a black hole. A trapped surface near the last stage of the starÂs collapse to its minimum size may still exist temporarily. Its formation depends on the details of collapse. Results for the case of Hawking flux of radiation with the Unruh initial state, will be given in a companion paper II.