Speaker
Description
We developed a variational approach to study a two-dimensional non-integrable quantum field theories through the lenses of integrable ones. We focus on the φ4 Landau- Ginzburg theory and compare it with the integrable Sinh-Gordon. We employ exact Vacuum Expectation Values and Form Factors of local operators of the Sinh-Gordon model for getting the best variational estimates of several quantities of the φ4 theory, such as the ground state energy on a finite volume or the physical mass as function of the coupling constant. We also apply Hamiltonian truncation methods at finite volume, studying the volume dependence of the variational method. At finite volume, the ground state energy, the mass and the elastic scattering matrix are studied numerically in the small-coupling regime.
