Discrete Quantum Integrability, Quantum Q-Systems, and Generalized Macdonald Operators

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This research project investigates questions at the intersection of mathematics and theoretical physics. The project is focused on questions that originate in statistical mechanics, which describes the average behavior of systems with large numbers of components. The algebraic study of these systems, and their symmetries, leads to new algebras, whose structure is in turn encoded combinatorially by collections of functions that arise as solutions to systems of equations. These new algebras, their generalizations, and the resulting combinatorics are the main topics to be studied. The research will be conducted in association with students at the graduate and undergraduate level, and will enhance our understanding of how these fields of study connect to each other. More precisely, the project concerns graded tensor products of cyclic current algebra modules, specifically Kirillov-Reshetikhin modules. The combinatorial framework is the quantum cluster algebra of the associated Q-systems, the solutions of which can be expressed in terms of plane tilings and non-intersecting path models. By investigating the discrete integrability of these systems, the investigators expect to produce conserved quantities, so far achieved only in type A. In turn, these should lead to difference equations for the graded characters of tensor product product, which generalize the difference Toda equations. Moreover, the solutions of these equations can be expressed as iterated action of difference creation operators, closely related to generalized Macdonald operators defined within the context of polynomial representations of double affine Hecke algebras. Relations to quantum affine and elliptic Hall algebras will also be investigated, as well as more combinatorial questions such as the existence of some (quantum) non-commutative counterpart to the Gessel-Viennot determinant for non-intersecting path enumeration. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.