Conservative solutions to the black hole information problem

Understand

We review the different options for resolution of the black hole loss of information problem.

• We classify them first into radical options, which require a quantum theory of gravity which has large deviations from semi-classical physics on macroscopic scales, such as non-locality or endowing horizons with special properties not seen in the semi-classical approximation, and conservative options, which do not need such help.
• Among the conservative options, we argue that restoring unitary evolution relies on elimination of singularities.
• We argue that this should hold also in the AdS/CFT correspondence.