Chaos and coarse-graining in holography: towards a new paradigm for quantum gravity

A new paradigm is emerging for black holes in quantum gravity. It is inspired by the general framework of gauge/gravity duality ('holography'), which allows for a consistent definition of quantum gravity in terms of dual non-gravitational quantum many-body systems. More concretely, the new paradigm will be rooted in an acceleration of developments in recent years due to: (i) the incorporation of quantum information theoretic concepts and methods into the way we use the holographic duality, and (ii) the discovery of new models of the duality which are unprecedentedly simple to study but nevertheless exhibit the key features of interest in quantum gravity. Armed with these powerful new tools, a consistent theory of quantum black holes is now within reach. Central objectives of my proposal are: (*) Develop a comprehensive and unifying theory of thermalization, dissipation, chaos, and randomness in quantum black holes and their dual many-body systems. (*) Determine the fate of fundamental quantum field theory constraints (unitarity, analyticity, thermality constraints,...) under the duality map and in quantum gravity. (*) Find a detailed model of black hole interiors in terms of degrees of freedom in the dual system. Work packages include investigations of quantum chaos in conformal and in disordered systems, the role of ensemble averages in quantum gravity, and an effective description of fluctuating black holes in the context of hydrodynamics. My methodology is tailored to synergize the unique combination of expertise in gravity, quantum field theory, and non-equilibrium dynamics that I have established: I will use a symmetry-based approach and effective field theory methods to make crucial aspects of the duality manifest in a unifying, general, and computationally efficient fashion. My approach is designed to identify universal aspects of quantum gravity and will thus lead to new insights that are generalizable beyond the context of the duality and even in cosmology.