Stringy black hole interiors

Amit Giveon, Nissan Itzhaki*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


It is well known that non-perturbative α corrections to the SL(2, ℝ)/U(1) cigar geometry are described via a condensation of a Sine-Liouville operator that schematically can be written as W+ + W, where W± describe a string with winding number ±1. This condensation leads to interesting effects in the cigar geometry that take place already at the classical level in string theory. Condensation of the analytically continued Sine-Liouville operator in the Lorentzian SL(2, ℝ)/U(1) black hole is problematic. Here, we propose that in the black hole case, the non-perturbative α corrections are described in terms of an operator that can be viewed as the analytic continuation of the fusion of W+ and W. We show that this operator does not suffer from the same problem as the analytically continued Sine-Liouville operator and argue that it describes folded strings that fill the entire black hole and, in a sense, replace the black hole interior. We estimate the folded strings radiation, and show that they radiate at the Hawking temperature.

Original languageAmerican English
Article number14
JournalJournal of High Energy Physics
Issue number11
StatePublished - 1 Nov 2019

Bibliographical note

Publisher Copyright:
© 2019, The Author(s).


  • 2D Gravity
  • Black Holes
  • Black Holes in String Theory


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