Mathematical Physics

Classical work by Thurston in the theory of surfaces gives symplectic co-ordinate charts on Teichmüller space, associated to quadratic differentials. Motivated by wall crossing in 4d field theories Gaiotto, Moore and Neitzke defined a generalization of these; giving maps from the moduli of one dimensional local systems on a spectral curve to the moduli space of n-dimensional local systems on a non-compact Riemann surface. I will describe joint work with M. Ionita which extends this construction to arbitrary reductive algebraic groups G. Time permitting I will describe the interpretation of this construction in terms of the wild Riemann--Hilbert Correspondence in the closely related setting of Frobenius manifolds.

From a probabilistic perspective, 2D quantum gravity is the study of natural probability measures on the space of all possible geometries on a topological surface. One natural approach is to take scaling limits of discrete random surfaces. Another approach, known as Liouville quantum gravity (LQG), is via a direct description of the random metric under its conformal coordinate. In this talk, we review both approaches, featuring a joint work with N. Holden proving that uniformly sampled triangulations converge to the so called pure LQG under a certain discrete conformal embedding.

In this talk we describe a systematic way of producing stochastic solutions to the Yang-Baxter equation from a “base solution” that is not necessarily stochastic. This gives rise to a wide class of new families of stochastic (Markovian) vertex models with integrable weights. In various cases, these models are more amenable to algebraic analysis than are their non-stochastic counterparts, sometimes leading to new (and at times unexpected) refined asymptotic results for them. In other cases, these stochastic systems are amenable to probabilistic analysis, yielding results that seem less transparent to access algebraically and that can occasionally shed new light on the original (non-stochastic) model. This is partially based on joint work with Alexei Borodin and Alexey Bufetov.

Connections between representation categories of quantum groups and vertex operator algebras (VOAs) have been studied since the 1990s starting with the pioneering work of Kazhdan and Lusztig. Recently, connections have been found between unrolled quantum groups and certain families of VOAs. In this talk, I will introduce unrolled quantum groups and describe their connections to the Singlet, Triplet, and Bp vertex operator algebras.

Factorization algebras provide a flexible language for describing the observables of a perturbative QFT, as shown in joint work with Kevin Costello. In joint work with Eugene Rabinovich and Brian Williams, we extend those constructions to a manifold with boundary for a special class of theories that includes, as an example, a perturbative version of the correspondence between chiral U(1) currents on a Riemann surface and abelian Chern-Simons theory on a bulk 3-manifold. Given time, I'll sketch a systematic higher dimensional version for higher abelian CS theory on an oriented smooth manifold of dimension 4n+3 with boundary a complex manifold of complex dimension 2n+1. (This talk will be very informal.)