The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian. On the other hand, the path integral over all topologically non-trivial metrics is asymptotically independent of the initial state. Thus the total path integral is unitary and information is not lost in the formation and evaporation of black holes. The way the information gets out seems to be that a true event horizon never forms, just an apparent horizon.
- GR Conference website summary of Stephen Hawking’s talk.
Whatever mate.
In reality, I feel like a complete fraud as a simple computer “scientist”. I can only imagine how humanists feel. No, actually I can’t.
P.S. The title is of course a reference to this.