Particle localization in field theory

Tales Rick Perche, José Polo-Gómez, Bruno de S. L. Torres +1 more

We present a fully relativistic model for localized probes in quantum field theory. Furthermore, we show that it is possible to obtain particle detector models from localized quantum field theories that interact with a free quantum field. In particular, a particle detector model is obtained when one traces out over inaccessible degrees of freedom of the localized field. This gives rise to a particle detector model, that is, a quantum degree of freedom that couples to a free field theory in an extended region of spacetime. Moreover, we show that the predictions of traditional particle detector models and fully relativistic localized fields completely coincide to leading order in perturbation theory.

Benjamin H. Feintzeig, J.T. Librande, Rory Soiffer

David Schroeren

In this paper, I provide a formal set of assumptions and give a natural criterion for a quantum field theory to admit particles. I construct a naïve approach to localization for a free bosonic quantum field theory and show how this localization scheme, as a consequence of the Reeh-Schlieder theorem, fails to satisfy this criterion. I then examine the Newton-Wigner concept of localization and show that it fails to obey strong microcausality and thus is subject to a more general version of the Reeh-Schlieder theorem. I review approaches to quantum field theoretic explanations of particle detection events and explain how particles can be regarded as emergent phenomena of a relativistic field theory. In particular, I show that effective localization of Hilbert space vectors is equivalent to an approximate locality of observable algebras.

G.F. Melloy

W. David Wick

In 2017, this author proposed, as a resolution of the Measurement Problem, that terms be added to Schrodinger's wavefunction equation, rendering it nonlinear. Said equation derived from a trick employed by S. Weinberg in 1989 which may be unfamiliar to most physicists, as well as uninterpretable in terms of local ("particle") interactions. Motivated by A. O. Barut's work on electrodynamics, here I analyze which kinds of nonlinear theories can be derived from Lagrangian field-theory by integrating out some fields. The issues of "What is a local interaction?" and "Might there be Micro- and Macro-fields?" arise. In the end, I will argue that my 2017 theory cannot be given a "particle" interpretation, nor be derived from a splitting into the two categories of fields.