Real time dynamics of gauge field theory with truncated Hamiltonian methods*

Truncated Hamiltonian methods (THM) have been studied as a powerful complement to lattice methods for the study of strongly coupled quantum field theory (QFT). THM have been used to compute spectra of the models, properties of bound states, symmetry breaking, (higher order) correlation functions, quantum chaos and particularly excel at real time evolution, a task difficult for Monte Carlo methods. They do not require a discretization of space-time and have been successfully applied to systems in 1 and 2 spatial dimensions.

Recently we have used THM to study real time dynamics of topologically nontrivial theories and gauge field theory in 1+1D. This has lead to an observation of a new nonequilibrium effect in strongly coupled QFT: quantum quenches, sudden changes of model parameters, in QFT with topological excitations lead to long range order in such theories, a phenomenon tightly connected to confinement.

In my talk, I will give an introduction to the THM methods, focus on the implementations for gauge theories, real time dynamics of the massive Schwinger model, and finally discuss the newly observed nonequilibrium emergence of long range order.