Calogero-Sutherland eigenfunctions with mixed boundary conditions and conformal field theory correlators

TL;DR

This paper constructs eigenfunctions of the Calogero-Sutherland model with mixed boundary conditions, linking them to conformal field theory correlators and potential applications in statistical physics models.

Contribution

It introduces a novel class of eigenfunctions with mixed boundary conditions, connecting quantum integrable systems to boundary conformal field theory.

Findings

Explicit ground and excited states for mixed boundary conditions

Eigenfunctions correspond to boundary CFT correlation functions

Potential applications to O(n) loop model configurations

Abstract

We construct certain eigenfunctions of the Calogero-Sutherland hamiltonian for particles on a circle, with mixed boundary conditions. That is, the behavior of the eigenfunction, as neighbouring particles collide, depend on the pair of colliding particles. This behavior is generically a linear combination of two types of power laws, depending on the statistics of the particles involved. For fixed ratio of each type at each pair of neighboring particles, there is an eigenfunction, the ground state, with lowest energy, and there is a discrete set of eigenstates and eigenvalues, the excited states and the energies above this ground state. We find the ground state and special excited states along with their energies in a certain class of mixed boundary conditions, interpreted as having pairs of neighboring bosons and other particles being fermions. These particular eigenfunctions are characterised by the fact that they are in direct correspondence with correlation functions in boundary conformal field theory. We expect that they have applications to measures on certain configurations of curves in the statistical O(n) loop model. The derivation, although completely independent from results of conformal field theory, uses ideas from the "Coulomb gas" formulation.