A light-front coupled cluster method

TL;DR

This paper introduces a novel nonperturbative approach for solving quantum field theories using a light-front coupled cluster method, which adapts many-body techniques to quantum field eigenproblems, reducing truncation issues.

Contribution

It develops a light-front coupled cluster method that reformulates the eigenvalue problem, offering a new computational framework for quantum field theories.

Findings

Derives effective eigenvalue equations in the valence sector.

Provides nonlinear integral equations for exponential operator functions.

Avoids some issues related to Fock-space truncation.

Abstract

A new method for the nonperturbative solution of quantum field theories is described. The method adapts the exponential-operator technique of the standard many-body coupled-cluster method to the Fock-space eigenvalue problem for light-front Hamiltonians. This leads to an effective eigenvalue problem in the valence Fock sector and a set of nonlinear integral equations for the functions that define the exponential operator. The approach avoids at least some of the difficulties associated with the Fock-space truncation usually used.