Found 5 result(s)

### 07.11.2018 (Wednesday)

#### AdS_2 holography - Mind the Cap!

Triangular Seminar Iosif Bena (IPHT)

 at: 15:00 KCLroom S-1.04 abstract: Black holes appear to lead to information loss, thus violating one of the fundamental tenets of Quantum Mechanics. Recent Information-Theory-based arguments imply that information loss can only be avoided if at the scale of the black hole horizon there exists a structure (commonly called fuzzball or firewall) that allows information to escape. I will discuss the highly-unusual properties that this structure must have and how these properties emerge in the realization of this structure in String Theory via branes, fluxes and topology. I will then describe the implication of this structure for AdS_2 holography.

### 21.04.2016 (Thursday)

#### Tachyonic Antibranes and the deSitter and Fuzzball Landscapes

Regular Seminar Iosif Bena (Saclay)

 at: 14:00 QMWroom G.O. Jones 610 abstract: Antibranes in backgrounds that have charge dissolved in fluxes are a key ingredient in constructing a landscape (Multiverse) of deSitter vacua in String Theory, and also of constructing microstate solutions corresponding to non-supersymmetric near-extremal black holes. There are several regimes of parameters in which one can study the physics of these antibranes, and I will show that in the regime of parameters where their gravitational backreaction is important, antibranes have a naked singularity that cannot be resolved either by brane polarization or by cloaking with a black hole horizon, and that signals a tachyonic instability. I will also present recent evidence that the theory on the wordvolume of anti-D3 branes is finite to all loops. I will conclude by discussing the implications of these results for the Multiverse paradigm and for the Fuzzball proposal.

### 09.12.2009 (Wednesday)

#### Multi-center non-BPS black holes (and what can they teach us about the information paradox)

Triangular Seminar Iosif Bena (Paris)

 at: 15:00 ICroom Blackett lecture room 3 abstract: I will review the construction of BPS and non-BPS multicenter black hole solutions, and describe a class of smooth solutions that have the same charges and asymptotics as black holes, but do not have a horizon. I will then discuss some of the properties of these solutions and argue that they should correspond to typical microstates of extremal black holes. If so, string theory would imply that a classical extremal black hole solution is a thermodynamic approximation of an ensemble of horizonless configurations, and that this solution stops giving a valid description of the physics at the scale of the horizon. I will finish by discussing the extension of this to non-extremal black holes and its implications for the information paradox.

### 04.06.2009 (Thursday)

#### Black hole microstate geometries and the information paradox

Regular Seminar Iosif Bena (Saclay)

 at: 14:00 QMWroom 410 B abstract:

### 21.02.2007 (Wednesday)

#### Geometric Transitions and Typical Black Hole Microstates

Triangular Seminar Iosif Bena (SPhT Saclay)

 at: 15:00 ICroom Lecture Theatre 1, Blackett Lab abstract: