Gravitational Holography

Coordinators: Xi Dong, Tom Faulkner, and Veronika Hubeny

Scientific Advisors: Juan Maldacena and Eva Silverstein

Understanding quantum gravity has been a long-standing goal of theoretical physics and is essential for solving challenging problems about black holes and cosmology. String theory provides a well-motivated approach to the subject which is still under rapid development. Using string theory and other insights from black hole thermodynamics, it has become increasingly clear that spacetime and gravity should be viewed as an emergent phenomenon arising from the complicated dynamics of some underlying quantum system ‘holographically’, in the sense that the fundamental degrees of freedom should be described by a lower-dimensional theory. There are by now many different approaches for studying this dynamics and generalizing the framework of holography to a wide range of quantum gravitational theories. A major goal of this program is to build on the recent developments to further explore the connections between these various ideas.

The focus of this program will include the following topics. 1) Holographic emergence of semi-classical description of gravity from some underlying building blocks, for example by using the connection between spacetime and entanglement. 2) Interesting models of holography including AdS/CFT, matrix models, quantum error-correcting codes, and tensor networks. 3) Constraints on effective gravitational theories such as various energy conditions and entropy bounds, as well as possible connections to bulk reconstruction. 4) Black hole information problem and probes of the black hole interior. 5) Quantum gravity in non-AdS spacetimes such as accelerating cosmologies.