Emergence of particles from bosonic quantum field theory

TL;DR

This paper explores how particles emerge from bosonic quantum field theories, highlighting the role of quantum and classical structures and comparing different theoretical approaches.

Contribution

It introduces two constructions of the one-particle subspace in bosonic quantum field theories, emphasizing the interplay between quantum and classical frameworks.

Findings

Two methods for constructing the one-particle subspace are presented.

The importance of quantum-mechanical and classical interplay is demonstrated.

Comments on the Newton-Wigner representation and related theories are provided.

Abstract

An examination is made of the way in which particles emerge from linear, bosonic, massive quantum field theories. Two different constructions of the one-particle subspace of such theories are given, both illustrating the importance of the interplay between the quantum-mechanical linear structure and the classical one. Some comments are made on the Newton-Wigner representation of one-particle states, and on the relationship between the approach of this paper and those of Segal, and of Haag and Ruelle.