Erickson Tjoa - The Unruh-DeWitt model and its joint interacting Hilbert space

Abstract: In this work we make the connection between the Unruh-DeWitt particle detector model applied to quantum field theory in curved spacetimes and the rigorous construction of the spin-boson model. With some modifications, we show that existing results about the existence of a spin-boson ground state can be adapted to the Unruh-DeWitt model. In the physically relevant setting involving massless fields in (3+1)-dimensional spacetimes, we argue that common choices of the spacetime smearing functions regulate the ultraviolet behaviour of the model but can still exhibit infrared divergences. 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.
Talk page: researchsemina...
Paper: arxiv.org/abs/...
3C-QFS, 16 May 2024