BLACK-HOLE MICROSTRUCTURE

Liste des contributions

1. Gravitational wave echoes, microstates and AdS/CFT

Bert Vercnocke

08/06/2020 12:00

Recorded version: http://www.youtube.com/watch?v=bSJS8yWdnrA

2. Making Microstate Geometries Spark Joy: Decluttering using Holomorphy and Dimensional Reduction

Daniel Mayerson

08/06/2020 14:30

Microstates of the three-charge D1-D5-P black hole - superstrata - are complicated solutions in 6D supergravity. I will discuss two ways to make Marie Kondo proud by "decluttering" and simplifying these solutions. First, by a clever choice of complex variables, one can quickly generalize the existing (single mode) superstrata to contain arbitrary holomorphic functions of these variables....

3. The VECRO hypothesis

Samir Mathur

08/06/2020 16:00

We consider three fundamental issues in quantum gravity: (a) the black hole information paradox (b) the unboundedness of entropy that can be stored inside a black hole horizon (c) the relation between the black hole horizon and the cosmological horizon. With help from the small corrections theorem, we convert each of these issues into a sharp conflict. We then argue that all three conflicts...

4. Panel: What does BMS and soft hair tell us about microstate structure?

Andrea Puhm, Geoffrey Compère, Malcolm Perry

08/06/2020 17:45

Moderator: Guillaume Bossard

Recorded discussion: https://www.youtube.com/watch?v=NtQJsSiv4Fw

5. Chaos at the rim of black hole and fuzzball shadows

Jose Morales

09/06/2020 12:00

We study the scattering of massless probes in the vicinity of the photon-sphere of asymptotically AdS/flat black holes and horizon-free microstate geometries (fuzzballs). We find that these exhibit a chaotic behaviour characterised by exponentially large deviations of nearby trajectories and compute the Lyapunov exponent \lambda governing the exponential growth. We find that fuzzballs and...

6. The Great Escape: Tunneling out of Microstate Geometries

Pierre Heidmann

09/06/2020 14:30

We discuss the quasi-normal modes in asymptotically-flat microstate geometries that have the same charge as a D1-D5-P black hole, but whose long BTZ-like throat ends in a smooth cap. In general the wave equation is not separable, but we find a class of geometries in which the non-separable term is negligible and we can compute the quasi-normal frequencies using WKB methods. The long throats of...

7. Stringy Structure at the BPS Bound

Emil Martinec

09/06/2020 16:00

We explore the stringy structure of 1/2-BPS states in little string theory and its AdS3 limit using worldsheet techniques. Duality in the worldsheet theory maps the geometrical (Lunin-Mathur) description of these states to a non-compact Landau-Ginsburg model whose superpotential is determined by the fivebrane source configuration. Singular limits of the 1/2-BPS configuration space result...

8. Panel: Microstates and Chaos

Ben Craps, Douglas Stanford, Emil Martinec, Iosif Bena

09/06/2020 17:45

Moderator: Costas Bachas

Recorded Version: https://youtu.be/MI5-c5-HLC0?t=11684

9. Session Cancelled

Marika Taylor

10/06/2020 12:00

At the request of this morning’s speaker, and out of respect for our colleagues who are striking today to protest racial discrimination and institutional violence, we have cancelled this morning's session of the conference.

10. What AdS_3 holography can tell us about black hole microstates?

Stefano Giusto

10/06/2020 14:30

Focusing on the paradigmatic example of the Strominger-Vafa black hole, I will review the insights on the gravitational description of black hole microstates coming from the dual 2D CFT. In particular I will discuss the correlators of "light" probe operators in the "heavy" states representing the microstates and their various limits.

Recorded Version: https://www.youtube.com/watch?v=31f_2G5DLaw

11. Gravity and randomness

Jan de Boer

10/06/2020 16:00

Recorded Version: https://youtu.be/31f_2G5DLaw?t=5673

12. Panel: Do typical states have horizons?

Iosif Bena, Jan de Boer, Juan Maldacena, Samir Mathur, Suvrat Raju

10/06/2020 17:45

Moderator: David Turton

Recorded Version: https://youtu.be/31f_2G5DLaw?t=11367

15. Some comments on wormholes and factorization

Phil Saad

11/06/2020 12:00

Recorded Version: http://www.youtube.com/watch?v=zB99h7iWKOg

14. The unreasonable effectiveness of semi-classical gravity without microstructure.

Ahmed Almheiri

11/06/2020 14:30

This talk will be about some surprising results from the semi-classical description of black holes. I will describe how this regime captures both the Hayden-Preskill protocol as well as the Page curve of evaporating black holes, indicative of unitary evaporation. The main tool will be the Island formula, as extension of the holographic entropy prescription to computing the entropy of the...

13. Entropies of subregions in two dimensional cosmological models

Juan Maldacena

11/06/2020 16:00

We discuss a two dimensional cosmological model consisting of two dimensional de-Sitter JT gravity plus a CFT . We compute entropies of subregions of the future asymptotic region.

Recorded version: https://youtu.be/wzVMDrfaRXA?t=5406

16. Panel: Islands, JT Gravity, AdS2 holography and Microstate Structure.

Ahmed Almheiri, Juan Maldacena, Samir Mathur, Steve Shenker

11/06/2020 17:45

Moderator: Marika Taylor

Recorded version: https://youtu.be/Vr61WnB6Ndw

17. Black Holes in string theory with duality twists.

Stefan Vandoren

12/06/2020 12:00

We consider 5D supersymmetric black holes in string theory compactifications that partially break supersymmetry. We compactify type IIB on T^4 and then further compactify on a circle with a duality twist to give Minkowski vacua preserving partial supersymmetry (N=6,4,2,0) in five dimensions. The effective supergravity theory is given by a Scherk-Schwarz reduction with a Scherk-Schwarz...

18. Is structure at the horizon required to resolve the information paradox?

Suvrat Raju

12/06/2020 14:30

We will describe recent work on how quantum information is stored in quantum gravity in asymptotically flat space. We will argue that all information that is available on future null infinity can also be obtained from a small region near its past boundary. This can be physically understood as the statement that information about the black hole microstate is always available outside the black...

19. JT, BTZ and the Island Phenomenon.

Erik Verlinde

12/06/2020 16:00

We study a simple model of black hole evaporation by considering a 1D QM system coupled to a 2D CFT on a strip, where both the 1D QM system and 2D CFT are chosen to have gravitational dual descriptions in terms of black holes in two and three dimensions respectively. By making use of the fact that JT gravity can be obtained via dimensional reduction of 3D gravity, the full system may be...