Thermal decay without information loss in horizonless microstate geometries

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 1 8 -BPS asymptotically AdS 3 × 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 × S 3 geometry of the black hole, but instead of having an event horizon, these geometries have a smooth highly-redshifted global-AdS 3 × 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 ∼ 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. arXiv:1905.05194v1 [hep-th]

BTZ trailing strings

“…The fact that the energy loss in the microstate geometries with long throats only differs from the energy loss in the black holes by terms that are 1/N 1 N 5 suppressed has been encountered before, both when studying certain limits of Wightman functions [9], and when evaluating correlators of two light and two heavy operators in these geometries [10]. It indicates that these geometries reproduce with high accuracy the features one expects of the bulk configurations dual to the typical microstates black hole.…”

Holomorphic waves of black hole microstructure

“…By defining n 0 = min{n ≥ 1, b n = 0}, |F | 2 vanishes as O(ρ 2n 0 ) at ρ = 0, then the cap metric is that of global AdS 3 to the same order. This property of the cap metric was an important element in understanding the scattering from single mode superstrata [7].…”

“…Nevertheless, quite a number of physically interesting microstate geometries are ultimately rather simple. Some can be reduced to (2+1)-dimensional backgrounds that are best described as smoothly capped BTZ geometries [2][3][4][5][6][7]. That is, the geometry is asymptotic, at infinity, to AdS 3 .…”

“…The throat between the two AdS 3 regions can be adjusted to create an arbitrarily high redshift. In some classes of these geometries, the massless scalar wave equation is even separable [4,[7][8][9]. This has enabled a great deal of analysis of such geometries and an investigation of their possible effects on microstructure [4,10,11,6,7].…”

“…The single mode superstrata have the virtue of being simple and yet capture some of the very interesting physical properties of capped BTZ geometries. On the other hand, such geometries are extremely coherent, highly atypical states and this leads to some behaviours, like sharp echoes [7], that are very atypical for microstate structure. While the states of the "supergraviton gas," described via (1.1) are still rather specialized 3 , one might hope that the corresponding superstrata may well start to exhibit somewhat more typical behaviour when it comes to the microstructure.…”