Snowmass White Paper: Micro- and Macro-Structure of Black Holes

Understand

The black-hole information paradox provides a stringent test of would-be theories of quantum gravity.

• String theory has made significant progress toward a resolution of this paradox, and has led to the fuzzball and microstate geometry programs.
• The central thesis of these programs is that only string theory has sufficiently many degrees of freedom to resolve black-hole microstructure, and that horizons and singularities are artifacts of attempting to describe gravity using a theory that has too few degrees of freedom to resolve the physics.
• Fuzzballs and microstate geometries recast black holes within string theory as horizonless and singularity-free objects that not only resolve the paradox but provide new insight into the underlying microstructure.