The information paradox: conflicts and resolutions

TL;DR

The paper argues that Hawking's information paradox hinges on the assumption of a regular horizon; in string theory, black hole microstates are horizonless fuzzballs, yielding order-unity horizon-scale modifications and a unitary radiation process. A key inequality shows small corrections cannot resolve the paradox, compelling a nonperturbative horizon structure. Fuzzball constructions reproduce black hole entropy via microstate counting and allow information to be imprinted in Hawking radiation, while high-energy probes recover approximate classical geometry. The work also outlines a cosmological conjecture where fractionated brane states drive early-universe expansion through rapid phase-space diffusion, linking black hole microphysics to cosmology.

Abstract

Many relativists have been long convinced that black hole evaporation leads to information loss or remnants. String theorists have however not been too worried about the issue, largely due to a belief that the Hawking argument for information loss is flawed in its details. A recently derived inequality shows that the Hawking argument for black holes with horizon can in fact be made rigorous. What happens instead is that in string theory black hole microstates have no horizons. Thus the evolution of radiation quanta with E ~ kT is modified by order unity at the horizon, and we resolve the information paradox. We discuss how it is still possible for E >> kT objects to see an approximate black hole like geometry. We also note some possible implications of this physics for the early Universe.

Figures (8)

• Figure 1: Electron positron pairs are created from the vacuum, and pass through the positive and negative grids. The two members of each pair are entangled with each other, generating an entanglement entropy $S_{ent}=N\ln 2$ between the left and right sides of the figure.
• Figure 2: The Penrose diagram of a black hole formed by collapse of the 'infalling matter'. The spacelike slices satisfy all the niceness conditions N.
• Figure 3: A schematic set of coordinates for the Schwarzschild hole. Spacelike slices are $t=const$ outside the horizon and $r=const$ inside. Assuming a solar mass hole, the infalling matter is $\sim 10^{77}$ light years from the place where pairs are created, when we measure distances along the slice. Curvature length scale is $\sim 3 ~km$ all over the region of evolution covered by the slices $S_i$.
• Figure 4: (a) If the string winding and momentum excitations could sit at a point, then we would get the usual black hole; in the lower diagram the geometry is shown with flat space at infinity, then a 'throat', ending in a horizon with a singularity inside. (b) The string cannot carry the momentum without transverse vibrations, and thus spreads over a horizon sized transverse area. The geometry depicted in the lower diagram has no horizon; instead the throat ends in a 'fuzzball'.
• Figure 5: (a) Rindler space (b) The Penrose diagram of the extended Schwarzschild hole. The region near the intersection of horizons is similar in the two cases.