## Thermal decay without information loss in horizonless microstate geometries

Iosif Bena, Pierre Heidmann, Ruben Monten, Nicholas P. Warner

SciPost Phys. 7, 063 (2019) · published 14 November 2019

- doi: 10.21468/SciPostPhys.7.5.063
- Submissions/Reports

### Abstract

We develop a new hybrid WKB technique to compute boundary-to-boundary scalar Green functions in asymptotically-AdS backgrounds in which the scalar wave equation is separable and is explicitly solvable in the asymptotic region. We apply this technique to a family of six-dimensional $\frac{1}{8}$-BPS asymptotically AdS$_3\,\times\,$S$^3$ horizonless geometries that have the same charges and angular momenta as a D1-D5-P black hole with a large horizon area. At large and intermediate distances, these geometries very closely approximate the extremal-BTZ$\,\times\,$S$^3$ geometry of the black hole, but instead of having an event horizon, these geometries have a smooth highly-redshifted global-AdS$_3\,\times\,$S$^3$ cap in the IR. We show that the response function of a scalar probe, in momentum space, is essentially given by the pole structure of the highly-redshifted global-AdS$_3$ modulated by the BTZ response function. In position space, this translates into a sharp exponential black-hole-like decay for times shorter than $N_1 N_5$, followed by the emergence of evenly spaced "echoes from the cap," with period $\sim N_1 N_5$. Our result shows that horizonless microstate geometries can have the same thermal decay as black holes without the associated information loss.

### Cited by 21

### Ontology / Topics

See full Ontology or Topics database.### Authors / Affiliations: mappings to Contributors and Organizations

See all Organizations.-
^{1}Iosif Bena, -
^{1}Pierre Heidmann, -
^{1}Ruben Monten, -
^{1}^{2}Nicholas Warner

- Agence Nationale de la Recherche [ANR]
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (through Organization: Commissariat à l'énergie Atomique et aux énergies Alternatives / Atomic Energy and Alternative Energies Commission [CEA])
- European Research Council [ERC]
- John Templeton Foundation
- United States Department of Energy [DOE]