Kyriakos Papadodimas

An Infalling Observer in AdS/CFT

A bstractWe describe the experience of an observer falling into a black hole using the AdS/CFT correspondence. In order to do this, we reconstruct the local bulk operators measured by the observer along his trajectory outside the black hole. We then extend our construction beyond the black hole horizon. We show that this is possible because of an effective doubling of the observables in the boundary theory, when it is in a purestate that is close to the thermal state. Our construction allows us to rephrase questions about information-loss and the structure of the metric at the horizon in terms of more familiar CFT correlators. It suggests that to precisely identify black-hole microstates, the observer would need to conduct measurements to an accuracy of

QCD and strongly coupled gauge theories: challenges and perspectives

{e^{{-{S_{\mathrm{BH}}}}}}

Emergent Spacetime and Holographic CFTs

. This appears to be inconsistent with the “fuzzball” proposal, and other recent proposals in which pure states in the ensemble of the black hole are represented by macroscopically distinct geometries. Furthermore, our description of the black hole interior in terms of CFT operators provides a natural realization of black hole complementarity and a method of preserving unitarity without “firewalls.”

Black Hole Interior in the Holographic Correspondence and the Information Paradox

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Correlation functions in holographic minimal models

A bstractWe discuss universal properties of conformal field theories with holographic duals. A central feature of these theories is the existence of a low-lying sector of operators whose correlators factorize. We demonstrate that factorization can only hold in the large central charge limit. Using conformal invariance and factorization we argue that these operators are naturally represented as fields in AdS as this makes the underlying linearity of the system manifest. In this class of CFTs the solution of the conformal bootstrap conditions can be naturally organized in structures which coincide with Witten diagrams in the bulk. The large value of the central charge suggests that the theory must include a large number of new operators not captured by the factorized sector. Consequently we may think of the AdS hologram as an effective representation of a small sector of the CFT, which is embedded inside a much larger Hilbert space corresponding to the black hole microstates.

A non-renormalization theorem for chiral primary 3-point functions

We show that, within the AdS/CFT correspondence, recent formulations of the information paradox can be reduced to a question about the existence of certain kinds of operators in the CFT. We describe a remarkably simple construction of these operators on a given state of the CFT. Our construction leads to a smooth horizon, addresses the strong subadditivity paradox, while preserving locality within effective field theory, and reconciles the existence of the interior with the growth of states with energy in the CFT. We also extend our construction to non-equilibrium states.

Small hairy black holes in AdS 5 × S 5

Abstract We compute exact three- and four-point functions in the W N minimal models that were recently conjectured to be dual to a higher spin theory in AdS3. The boundary theory has a large number of light operators that are not only invisible in the bulk but grow exponentially with N even at small conformal dimensions. Nevertheless, we provide evidence that this theory can be understood in a 1 N expansion since our correlators look like free-field correlators corrected by a power series in 1 N . However, on examining these corrections we find that the four-point function of the two bulk scalar fields is corrected at leading order in 1 N through the contribution of one of the additional light operators in an OPE channel. This suggests that, to correctly reproduce even tree-level correlators on the boundary, the bulk theory needs to be modified by the inclusion of additional fields. As a technical by-product of our analysis, we describe two separate methods—including a Coulomb gas type free-field formalism—that may be used to compute correlation functions in this theory.

Degenerate stars and gravitational collapse in AdS/CFT

A bstractIn this note we prove a non-renormalization theorem for the 3-point functions of 1/2 BPS primaries in the four-dimensional

Holographic neutron stars

\mathcal{N} = 4

The chiral ring of AdS3/CFT2 and the attractor mechanism

SYM and chiral primaries in two dimensional