Ground States of Quantum Electrodynamics with Cutoffs

TL;DR

This paper proves the existence of a finite-multiplicity ground state in a quantum electrodynamics system with cutoffs, under specific localization and regularity conditions, for all coupling strengths.

Contribution

It establishes the existence and finiteness of the ground state in QED with cutoffs under certain conditions, extending previous results.

Findings

Ground state exists for all coupling constants.

Ground state multiplicity is finite.

Results apply under localization and regularity assumptions.

Abstract

In this paper, we investigate a system of quantum electrodynamics with cutoffs. The total Hamiltonian is defined on a tensor product of a fermion Fock space and a boson Fock. It is shown that, under spatially localized conditions and momentumregularity conditions, the total Hamiltonian has a ground state for all values of coupling constants. In particular, its multiplicity is finite.