High Energy Theory Seminar

Quantum field theories with a large number of fields offer a number of simplifications, and in some cases allow for computations at strong coupling. Two canonical examples are field theories where the fundamental fields are vectors, such as the O(N) vector model, and field theories where the fundamental fields are matrices, such as SU(N) gauge theories. We discuss a recently discovered new class of large N theories - in which the fundamental fields are neither vectors nor matrices, but tensors. In one dimension, these are part of the SYK family of models. These models enjoy the extraordinary property of having, at strong coupling, emergent conformal invariance as well as maximal chaos, while nevertheless being solvable. This unique combination allows one to construct tractable models of AdS/CFT duality and black holes, as well as of strongly correlated many body systems.In this talk, we solve the SYK model, computing all point correlation functions. The solution has remarkable simplicity and structure. We discuss the implications for our understanding of conformal field theory, of string theory in two dimensions, and of holography and the emergence of spacetime.