Detectors, Reference Frames, and Time

by Alexander R. H. Smith

Overview

This thesis uses the tools of quantum information science to uncover fascinating new insights about the intersection of quantum theory and relativity. It is divided into three self-contained parts, the first of which employs detector models to investigate how the information content of quantum fields depends on spacetime curvature and global spacetime topology. The behavior of Unruh-DeWitt detectors on curved spacetimes are investigated, following which these detectors are used to probe the vacuum state of a scalar field in various topologies. This leads to a generalization of the entanglement harvesting prool involving detectors in arbitrary curved spacetimes admitting a Wightman function. The second part extends the theory of quantum reference frames to those associated with noncompact groups. Motivated by the pursuit of a relational relativistic quantum theory where the group of reference frames is the Poincaré group, the author then generalizes a communication prool between two parties lacking a common reference frame to the scenario where the group of transformations of their reference frame is a one-dimensional noncompact Lie group. Finally, the third part, inspired by theories of quantum gravity, generalizes the conditional probability interpretation of time, a proposed mechanism for time to emerge from a fundamentally timeless Universe. While the conditional probability interpretation of time is based upon conditioning a solution to the Wheeler-DeWitt equation on a subsystem of the universe that acts a clock, the author extends this approach to include an interaction between the system being used as a clock and a system whose evolution the clock is tracking.

Product Details

ISBN-13:	9783030109998
Publisher:	Springer International Publishing
Publication date:	07/05/2019
Series:	Springer Theses
Edition description:	1st ed. 2019
Pages:	167
Product dimensions:	6.10(w) x 9.25(h) x (d)

About the Author

Alexander Smith received his PhD from the University of Waterloo in 2017. He holds an NSERC Postdoctoral Fellowship, and a Junior Fellowship in the Society of Fellows, both at Dartmouth College.

Table of Contents

Chapter1. Introduction.- Part1: Detectors in Curved Spacetimes.- Chapter2. Quantum Field Theory on Curved Spacetimes.- Chapter3. The Unruh-DeWitt Detector and Entanglement Harvesting.- Chapter4. Unruh-DeWitt Detectors in Quotients of Minkowski Space.- Chapter5. Unruh-DeWitt Detectors in (2+1)-dimensional Black Hole Spacetimes.- Part2: Quantum Reference Frames.- Chapter6. Quantum reference frames associated with noncompact groups.- Chapter7. Communication without a shared reference frame.- Part3: Quantizing Time.- Chapter8. The conditional probability interpretation of time.