Evaporation of 2-d Black Holes: Why there is no Information Loss
Professor A. Ashtekar (Penn State University, Pennsylvania/USA)

Left to themselves, black holes evaporate through quantum processes. In the external field approximation their radiation is well-approximated by a thermal state. Therefore it first appears that one could form a black hole through the gravitational collapse of a pure state and at the end of evaporation one would be left with a mixed thermal state. This reasoning leads to the "issue of information loss." Through a 2-dimensional model that mimics many features of the 4-d spherical black holes, I will show that several of the standard assumptions about the evaporation process are flawed and argue that there is in fact no information loss because the quantum space-time is larger than what one might naively expect. This analysis also brings out unexpected universalities associated with the evaporation process.