Do the postulates of quantum mechanics survive in quantum gravity? The probabilistic interpretation of amplitudes, enforced by the unitarity of time evolution, is not guaranteed within the path integral formulation and has to be checked. Leveraging the gravitational path integral, we find a non-perturbative mechanism whereby a sum over smooth geometries leads to isometric rather than unitary evolution, which we demonstrate … Read More
Abstract: We discuss dilaton gravity with potentials that are deformed away from JT gravity. We discuss semi-classical solutions with these potentials and elucidate new complex saddles at fixed energy which contribute to the density of states. We also discuss how to reproduce the semi-classical limit of a formula for the density of states first derived by using the connection between … Read More
Abstract: The idea that spacetime may be discrete in the UV, possibly at the Planck scale, has been fraught with issues due to generically strong effects of such discreteness on the flow of a quantum field theory down to the IR. Nevertheless, recent work on two dimensional models of holography seem to provide an example of the emergence of spacetime from … Read More
Abstract: Geodesics play an important role in holographic quantities such as entropy and complexity. It is therefore of interest to understand to what extent these results can be generalized to De Sitter space. In this talk, I will derive a geodesic approximation to two-point correlation functions of heavy fields in De Sitter space. Intriguingly, this approximation involves a sum over … Read More
Abstract: We describe the dynamical evaporation of a black hole as the classical evolution in time of a black hole in an Anti-de Sitter braneworld. A bulk black hole whose horizon intersects the brane yields the classical bulk dual of a black hole coupled to quantum conformal fields. The evaporation of this black hole happens when the bulk horizon slides off … Read More
Abstract: Scar states are non-thermalizing states which violate eigenstate thermalization hypothesis. I argue that all holographic systems in any number of dimensions possess scar states. The corresponding gravity solutions are well-known oscillons, geons and boson stars.
Abstract: “I review a class of quantum error correcting codes that directly takes into account the large-N aspects of holographic theories. I will discuss some aspects of the vacuum sector of these codes and use them to show the equivalence between two different approaches to entanglement wedge reconstruction.”
Abstract: Recently, Danielson, Satishchandran, and Wald proposed a novel mechanism for decoherence in spacetimes with Killing horizons. When Alice performs a Stern-Gerlach type experiment outside the horizon, there is a fundamental rate of decoherence due to the emission of soft gravitons/photons that radiate away information. In this talk, I will sharpen and generalize this mechanism by recasting the gedankenexperiment in … Read More
Abs: Historically tensor networks have been helpful models of AdS/CFT, but there have always been some aspects that they fail to capture, particularly those involving the time direction. In this talk I will take the perspective that we can learn a lot from trying to incorporate these aspects into tensor networks, and I will explain some progress on resolving the … Read More
Abstract: We analyze the algebra of boundary observables in canonically quantised JT gravity with or without matter. In the absence of matter, this algebra is commutative, generated by the ADM Hamiltonian. After coupling to a bulk quantum field theory, it becomes a highly noncommutative algebra of Type II∞ with a trivial center. As a result, density matrices and entropies on … Read More