My talk abstract: We study operator entanglement measures of the unitary evolution operators of (1+1)-dimensional conformal field theories (CFTs), aiming to uncover their scrambling and chaotic behaviors. In particular, we compute the bi-partite and tri-partite mutual information for various configurations of input and output subsystems, and as a function of time. We contrast three different CFTs: the free fermion theory, … Read More

Scattering amplitudes in any four-dimensional quantum theory of gravity are constrained by an infinite number of symmetries including a two-dimensional conformal symmetry which acts on the celestial sphere at lightlike infinity. Recent work exploiting these constraints for a holographic description of quantum gravity in asymptotically flat spaces is described.

Abstract: 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. I will then propose a holographic dual CFT that matches exactly the entire continuous spectrum of the superstring. I will conclude with a few observations on the … Read More

Abstract: We show that Weinberg’s leading soft photon theorem in massless quantum electrodynamics (QED) implies the existence of an infinite-dimensional large gauge symmetry, which acts non-trivially on the null boundaries of (d+2)-dimensional Minkowski spacetime. These symmetries are parameterized by an arbitrary function of the d-dimensional celestial sphere living at null infinity. This extends the equivalence between Weinberg’s leading soft photon … Read More

I will discuss the basics of a unitary and UV complete string theory described by a 2D QFT which in flat spacetime enjoys a (string-)Galilean invariant global symmetry. This type of string theory is referred to as nonrelativistic string theory. The spacetime geometry that this string theory couples to is non-Riemannian and is dubbed as the string Newton-Cartan geometry. I … Read More

Abstract: I will discuss ideas on how gravity can be an emergent interaction in QFT, what are its general features and properties and what could be the possible implications for realistic gravitational physics.

Abstract: “In this talk, I will discuss various applications of constructing holographic CFT states via Euclidean path-integrals with boundaries. First, I will discuss how to describe smooth spacetimes via multipart entangled states of many non-interacting systems. As a second application, I will describe the construction of certain black hole microstates for which the behind-the-horizon geometry can be deduced explicitly. The … Read More

HEP-QIS Seminar Abstract: A simple qubit model of black hole evaporation is studied. Within this model, we formulate versions of the firewall paradoxes and resolve them. We find that, even though the partner mode of the outgoing Hawking modes can be reconstructed from the early radiation, these modes are protected against seemingly dangerous operations on the radiation, e.g., low-complexity unitary … Read More