Quasinormal modes of supersymmetric microstate geometries from the D1-D5 CFT

Abstract

We revisit the study of the probe scalar quasinormal modes of a class of three-charge supersymmetric microstate geometries. We compute the real and imaginary parts of the quasinormal modes and show that in the parameter range when the geometries have large AdS region, the spectrum is precisely reproduced from a D1-D5 orbifold CFT analysis. The spectrum includes the slow decaying modes pointed out by Eperon, Reall, and Santos. We analyse in detail the nature of the quasinormal modes by studying the scalar wavefunction. We show that these modes correspond to slow leakage of excitation from AdS throat to infinity.

The great escape: tunneling out of microstate geometries

“…shown in [18] that there exist modes that decay extremely slowly, and this was confirmed by a matched-asymptotic-expansion calculation of the decay time [19]. From a mathematical perspective, this extremely slow decay of a wave equation in a background was the slowest ever found, and this has created some interest in the mathematical community [20][21][22].…”

“…Intuitively, it is natural to expect that the cap region will be the repository of all the microstate structure and thus one should expect infalling matter to be trapped there for a very long time. Starting with [15], there have now been several investigations [16][17][18][19] of trapping of matter in either BPS or non-BPS microstate geometries. Furthermore, it was JHEP04(2021)112…”

“…There is another problem with the decay-time analysis of [18], which can be best seen when analyzing the slowly-decaying modes using a matched asymptotic expansion [19]. From a mathematical perspective, the allowed wave-numbers are unbounded.…”

“…1 The purpose of this paper is to calculate the long-term trapping in, and tunneling from, a family of asymptotically-flat microstate geometries that have the same charges and the same long AdS 2 throat as a three-charge black hole with a large event horizon. 2 There is a standard approach to this class of problems in which one uses matched asymptotic expansions [16][17][18][19]. Essentially, one constructs the modes in an asymptotically AdS space-time, and then matches the AdS asymptotics to the Bessel function asymptotics that are the staple of flat-space scattering problems.…”

Stringy structure at the BPS bound

“…We can now present a refinement of the picture of evolution of perturbed BPS states given in [104,105], which analyzed such perturbations at the level of supergravity (see also [106][107][108]). A feature of 1/2-BPS Lunin-Mathur geometries (and the related 3-charge geometries obtained by fractional spectral flow in the spacetime CFT [38,39,42]) is that the supertube source profile is the locus of an evanescent ergosurface, where the globally null Killing vector field ∂ u becomes orthogonal to the Killing vector field ∂ y .…”