The Unruh-DeWitt model and its joint interacting Hilbert space

Autor(en)

Erickson Tjoa, Finnian Gray

Abstrakt

In this work we make the connection between the Unruh-DeWitt (UDW) particle detector model applied to quantum field theory in curved spacetimes and the rigorous construction of the spin-boson (SB) model. With some modifications, we show that existing results about the existence of a SB ground state can be adapted to the UDW model. In the most relevant scenario involving massless scalar fields in (3+1)-dimensional globally hyperbolic spacetimes, where the UDW model describes a simplified model of light-matter interaction, we argue that common choices of the spacetime smearing functions regulate the ultraviolet behaviour of the model but can still exhibit infrared (IR) divergences. In particular, this implies the well-known expectation that the joint interacting Hilbert space of the model cannot be described by the tensor product of a two-dimensional complex Hilbert space and the Fock space of the vacuum representation. We discuss the conditions under which this problem does not arise and the relevance of the operator-algebraic approach for better understanding of particle detector models and their applications.Our work clarifies the connection between obstructions due to Haag’s theorem and IR bosons in the SB models, and paves the way for more rigorous study of entanglement and communication in the UDW framework involving multiple detectors.

Organisation(en)

Gravitationsphysik

Externe Organisation(en)

Max-Planck-Institut für Quantenoptik

Journal

Journal of Physics A: Mathematical and Theoretical

Band

57

Anzahl der Seiten

45

ISSN

1751-8113

DOI

https://doi.org/10.48550/arXiv.2402.05795

Publikationsdatum

08-2024

Peer-reviewed

Ja

ÖFOS 2012

103024 Quantenfeldtheorie, 103028 Relativitätstheorie, 103012 Hochenergiephysik

Schlagwörter

ASJC Scopus Sachgebiete

Statistical and Nonlinear Physics, Statistics and Probability, Modelling and Simulation, Mathematical Physics, Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4e956d35-47fe-462f-828a-01295f301e70