This paper surveys the status of scientific realism in relation to quantum physics, focusing on the problem of underdetermination.

Many attempts have been made to provide Quantum Field Theory with conceptually clear and mathematically rigorous foundations; remarkable examples are the Bohmian and the algebraic perspectives respectively. In this essay we introduce the dissipative approach to QFT, a new alternative formulation of the theory explaining the phenomena of particle creation and annihilation starting from nonequilibrium thermodynamics. It is shown that DQFT presents a rigorous mathematical structure, and a clear particle ontology, taking the best from the mentioned perspectives. Finally, after the (...) discussion of its principal implications and consequences, we compare it with the main Bohmian QFTs implementing a particle ontology. (shrink)

The general study of the ontology of quantum field theories (QFTs) concerns whether particles or fields are more fundamental. Both views are well-motivated, although each is subject to some serious criticism. Given that the current versions of the particle interpretation and the field interpretation are not satisfying, I propose a mixed ontology of particles and fields in the framework of QFT. I argue that the ontological question should focus on how to view particles and fields consistently in QFT, provided that (...) they are the natural candidates for the ontology of QFT. In particular, based on this reading, I adopt a functionalist reading of ontology and defend a mixed ontology of QFT. I address a paradigmatic case of the mixed ontology approach: a particle/field duality defined in terms of functional equivalence between particles and fields. Functionalism about ontology provides new insight into resolving the problem of unitarily inequivalent representations, which is one of the major interpretational issues of QFT. (shrink)

A number of arguments purport to show that quantum field theory cannot be given an interpretation in terms of localizable particles. We show, in light of such arguments, that the classical ħ→0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbar \rightarrow 0$$\end{document} limit can aid our understanding of the particle content of quantum field theories. In particular, we demonstrate that for the massive Klein–Gordon field, the classical limits of number operators can be understood to encode local information about particles (...) in the corresponding classical field theory. (shrink)

The extremely successful _Standard Model of Particle Physics_ allows one to define the so-called _Elementary Particles_. From another point of view, how can we think of them? What kind of a status can be attributed to Elementary Particles and their associated quantised fields? Beyond the unprecedented efficiency and reach of quantum field theories, the current paper attempts at understanding the nature of what these theories describe, the enigmatic reality of the quantum world.