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Monday Jun 3 (ENS, salle L357/359) |
Tuesday Jun 4 (IHP, amphithéâtre Hermite) |
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|---|---|---|
| 10:00 | Kleban | Le Floch |
| 11:30 | Porrati | Dubovsky |
| 14:00 | Verlinde | Kutasov |
| 15:30 | Gaberdiel | Guica |
| 17:00 | Bachas | Discussion |
Talks
Bachas: Ultraviolet Complete Massive Gravity
I will present an embedding of massive AdS supergravity in string theory. I will discuss its holographic interpretation, and trace the breakdown of the effective low-energy Stueckelberg action to the condensation of spin-2 modes from the unprotected (non-BPS) sector of the theory.
Gaberdiel : An exact AdS3 / CFT2 duality
Superstring theory on AdS3 x S3 x T4 with the smallest amount of NS-NS flux (k = 1) is shown to be dual to the spacetime CFT given by the large N limit of the free symmetric product orbifold Sym_N (T4). To define the worldsheet theory at k = 1, the hybrid formalism is employed in which the AdS3 x S3 part is described by the psu(1, 1|2)_1 WZW model (which is well defined). Unlike the case for k \geq 2, it turns out that the string spectrum at k = 1 does not exhibit the long string continuum, and perfectly matches with the large N limit of the symmetric product. In addition, the algebraic relations and the structure of the correlation functions of the symmetric product are also correctly reproduced from the world-sheet. Finally, I will explain how the analysis generalises for k>1.
Guica: On the large N holographic dictionary for TTbar deformed CFTs
Kleban: A novel class of conformal field theories
Inspired by the late-time dynamics of bubble nucleation in de Sitter spacetime, I will present a class of conformally invariant stochastic models in two dimensions. Some - based on random, scale invariant ensembles of disks - are invariant under global conformal transformations but exhibit pathologies that indicate they do not respect local conformal invariance. Another class of models, based on random, scale invariant ensembles of closed, self-intersecting Brownian paths, appear to define fully conformal theories with positive central charge and operator dimensions. These "Brownian loop soups" can be thought of as a generalization of N free bosons to non-integer N. I will define a set of primary operators in these ensembles and compute their conformal dimension, and comment on various properties of higher-point correlation functions.
Kutasov: The power of string theory in T-Tbar and related theories
I will discuss the interplay of string theory and solvable irrelevant deformations of two dimensional CFT’s. String theory provides a powerful approach for computing the spectrum and torus partition sum of the deformed field theories, while the deformed field theories shed light on holography beyond asymptotically AdS spacetimes, and physical consequences of various pathologies of the bulk geometries.
Le Floch: KdV charges ride the TTbar flow (and JTbar)
Under the TTbar deformation of 2d QFTs the energy spectrum
evolves according to the Burgers equation. I will derive the
corresponding evolution equation for other conserved charges, such as higher-spin KdV charges. These techniques apply partially to the JTbar and T_s Tbar deformations. Separately, background gauge fields for a flavour symmetry current J (of spin 0)
give access to the spectrum of a CFT deformed by TTbar+JTbar.
Time-permitting I will combine the two methods to follow KdV charges
under the TTbar+JTbar deformation.
Porrati: A proposal for the CFT dual for superstrings on ADS3xS1xS3xS3 at the string radius
After a review of the spectrum of superstrings on the AdS3 WZW background, I will review evidence for a phase transition when the AdS radius becomes of order of the string length. Next I will propose a holographic dual CFT that matches exactly the entire continuous spectrum of the superstring. I will conclude with a few observations on the role of interactions and discrete, short-string states.
Verlinde: TTbar deformed CFT as a non-critical string
