The Schr\"odinger Representation and 3d Gauge Theories

TL;DR

This review explores the Hamiltonian Schr"odinger representation of 3D Yang-Mills theories, emphasizing gauge-invariant variables, nonperturbative calculations, and comparisons with lattice results, including string tension and vacuum entanglement.

Contribution

It develops a gauge-invariant Hamiltonian framework in 3D Yang-Mills theory and applies it to compute nonperturbative quantities, extending to supersymmetric and Chern-Simons variants.

Findings

Calculated string tension and Casimir energy consistent with lattice results

Developed gauge-invariant variables for Hamiltonian analysis

Discussed vacuum entanglement and string breaking effects

Abstract

In this review we consider the Hamiltonian analysis of Yang-Mills theory and some variants of it in three spacetime dimensions using the Schr\"odinger representation. This representation, although technically more involved than the usual covariant formulation, may be better suited for some nonperturbative issues. Specifically for the Yang-Mills theory, we explain how to set up the Hamiltonian formulation in terms of manifestly gauge-invariant variables and set up an expansion scheme for solving the Schr\"odinger equation. We review the calculation of the string tension, the Casimir energy and the propagator mass and compare with the results from lattice simulations. The computation of the first set of corrections to the string tension, string breaking effects, extensions to the Yang-Mills-Chern-Simons theory and to the supersymmetric cases are also discussed. We also comment on how entanglement for the vacuum state can be formulated in terms of the BFK gluing formula. The review concludes with a discussion of the status and prospects of this approach.