Information Retention by Stringy Black Holes

Abstract

Building upon our previous work on two-dimensional stringy black holes and its extension to spherically-symmetric four-dimensional stringy black holes, we show how the latter retain information. A key rôle is played by an infinite-dimensional $W_\infty$ symmetry that preserves the area of an isolated black-hole horizon and hence its entropy. The exactly-marginal conformal world-sheet operator representing a massless stringy particle interacting with the black hole necessarily includes a contribution from $W_\infty$ generators in its vertex function. This admixture manifests the transfer of information between the string black hole and external particles. We discuss different manifestations of $W_\infty$ symmetry in black-hole physics and the connections between them.

29 pages, 18th International Conference From the Planck Scale to the Electroweak Scale, 25-29 May 2015, Ioannina, Greece; Updated version, contains a new subsection 5.4 on the relationship between Hawking radiation and W-infinity symmetries with additional references