1) Where does all the information in the universe reside?

A central goal in our quest to understand nature is the ability to predict observables, i.e., the outcomes of experiments. In order to make such predictions, we need to gain complete knowledge of the present state of the system of interest, and then employ the physical laws governing the evolution of the system. Let us consider the whole universe as our system. If we wish to predict the future of the universe and postdict its past, we might expect that we need to make observations everywhere in the universe. However, recently, we have come to suspect a radical departure from this expectation. In this talk, I will provide an accessible introduction to the idea that all the information in the universe could be available to observers who are only on its boundary. I will also discuss the implications of the boundary description for understanding bulk gravitational processes, and for resolving longstanding questions about the nature of black holes. I will end with an overview of our progress in understanding how this information is encoded on the boundary. This overview will be expanded upon in the subsequent talks.

2) Asymptotically flat spacetimes and the holographic nature of quantum information storage

Consider any region of the universe with the boundary far away from any masses. The mathematical description of such a region is captured by the notion of asymptotically flat spacetimes. We will introduce these space-times and their boundary structure. For massless fields, the relevant boundary is null infinity. We will describe the associated gravitational phase space and the Hilbert space of states both in four and higher dimensions. Restricting to massless states in four dimensions, we will argue that observers only at the past of future null infinity have access to the full information of these states that observers in all of the spacetime do.

3) Bulk and boundary correlators, their conformality, and an organizing principle for Feynman diagrams

Dynamical information about interactions occurring in the bulk of the space-time is captured in the S-matrix, entries of which are probabilities of transitions between states. We describe how the S-matrix is encoded in the boundary correlators of flat spacetimes. Usually, for convenience, field theory correlators and S-matrix elements are computed in momentum space. However, for the purposes of a boundary description, we would like to be able to compute them directly in position space. We describe our progress towards making the position space computation tractable. We find that all correlators can be cast as if they were coming from the more symmetric conformal field theories, where computations can, and usually are, carried out in position space. Regardless of our motivations, this representation could be used as a new approach to computing observables for non-gravitational processes too, such as those regularly probed in various laboratories including colliders. As another aside, we are led to a new principle that organizes the usual momentum space Feynman diagrams and could aid in their computation.