Correction to Hawking radiation in non-singular gravitational collapse

Abstract

Recent studies have shown that quantum gravity introduces important corrections to the process of spherically symmetric gravitational collapse expected from general relativity. In particular, instead of falling into a central singularity, the collapsing body undergoes a bounce and eventually exits its Schwarzschild radius, and this entire process of collapse and rebound can occur in a single asymptotic region. In this paper, particle creation during such non-singular gravitational collapse is studied. It is shown that the probability of spontaneous emission of particles differs from the well-known probability of Hawking radiation from classical gravitational collapse. It is argued that the different result implies a deviation from thermality. Some arguments are also adduced concerning how the Hawking process during non-singular dust collapse could potentially remove shell crossing singularities.

Figures (3)

• Figure 1: Example of non-singular gravitational collapse. The blue line represents the boundary of the collapsing star and the region inside the red figure is trapped.
• Figure 2: A typical particle creation event. A particle-antiparticle pair is separated by the background gravitational field near the horizon at $r=p$. The particle travels outwards towards future null infinity. The antiparticle follows an ingoing path, eventually annihilating a shell of matter either before reaching the inner horizon ($q=r_{H_I}+\epsilon$) or at the inner horizon ($q = r_{H_I} -\epsilon$).
• Figure 3: Choice of contour in evaluating $I_1$.