Diffusions, quantum fields and groups of mappings

Meaning

10.1093/oso/9780198714057.003.0012 ◽

2017 ◽

Author(s):

Richard Healey

Keyword(s):

Quantum Theory ◽

Physical Object ◽

Quantum Fields ◽

Conceptual Content ◽

Classical Physics ◽

Physical Context

Novel quantum concepts acquire content not by representing new beables but through material-inferential relations between claims about them and other claims. Acceptance of quantum theory modifies other concepts in accordance with a pragmatist inferentialist account of how claims acquire content. Quantum theory itself introduces no new beables, but accepting it affects the content of claims about classical magnitudes and other beables unknown to classical physics: the content of a magnitude claim about a physical object is a function of its physical context in a way that eludes standard pragmatics but may be modeled by decoherence. Leggett’s proposed test of macro-realism illustrates this mutation of conceptual content. Quantum fields are not beables but assumables of a quantum theory we use to make claims about particles and non-quantum fields whose denotational content may also be certified by models of decoherence.

Download Full-text

A path integral formulation for particle detectors: the Unruh-DeWitt model as a line defect

Journal of High Energy Physics ◽

10.1007/jhep03(2021)076 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Ivan M. Burbano ◽

T. Rick Perche ◽

Bruno de S. L. Torres

Keyword(s):

Path Integral ◽

Degrees Of Freedom ◽

Wilson Line ◽

Transition Probability ◽

Relativistic Quantum ◽

Quantum Fields ◽

Line Defect ◽

Particle Detectors ◽

Nonlocal Operators ◽

Detector Model

Abstract Particle detectors are an ubiquitous tool for probing quantum fields in the context of relativistic quantum information (RQI). We formulate the Unruh-DeWitt (UDW) particle detector model in terms of the path integral formalism. The formulation is able to recover the results of the model in general globally hyperbolic spacetimes and for arbitrary detector trajectories. Integrating out the detector’s degrees of freedom yields a line defect that allows one to express the transition probability in terms of Feynman diagrams. Inspired by the light-matter interaction, we propose a gauge invariant detector model whose associated line defect is related to the derivative of a Wilson line. This is another instance where nonlocal operators in gauge theories can be interpreted as physical probes for quantum fields.

Download Full-text