Giving Hamiltonian Truncation a Boost

TL;DR

This paper explores Hamiltonian truncation in boosted frames, demonstrating that finite momentum reduces volume dependence in the 2d Ising model, thus improving the accuracy of infinite volume observable calculations.

Contribution

It introduces a method to enhance Hamiltonian truncation accuracy by analyzing boosted frames, specifically in the 2d Ising model with thermal and magnetic deformations.

Findings

Finite momentum reduces volume dependence in spectra.

Time-dependent correlators become more volume-independent.

Improved determination of infinite volume observables.

Abstract

We study Hamiltonian truncation in boosted frames. We consider the thermal and magnetic field deformations of the 2d Ising model using TCSA at finite momentum. We find that even with moderate momenta, the spectrum and time-dependent correlation functions become significantly less dependent on the volume of the system. This allows for a more reliable determination of infinite volume observables.