Browsing Theses by Subject "quantum field theory"
Now showing items 119 of 19

Aspects of Quantum Field Theory in Enumerative Graph Theory
(University of Waterloo, 20221024)While a quantum field theorist has many uses for mathematics of all kinds, the relationship between quantum field theory and mathematics is far too fluid in the world of modern research to be described as the simple provision ... 
A Combinatorial Tale of Two Scattering Amplitudes: See Two Bijections
(University of Waterloo, 20220107)In this thesis, we take a journey through two different but not dissimilar stories with an underlying theme of combinatorics emerging from scattering amplitudes in quantum field theories. The first part tells the tale ... 
Correlation and Communication via a Quantum Field
(University of Waterloo, 20190715)We study the ability of qubit detectors to i) extract correlations from, and ii) transmit quantum information through, a quantum field. We start by perturbatively studying the harvesting of correlations from thermal and ... 
A Covariant Natural Ultraviolet Cutoff in Inflationary Cosmology
(University of Waterloo, 20130828)In the field of quantum gravity, it is widely expected that some form of a minimum length scale, or ultraviolet cutoff, exists in nature. Recently, a new natural ultraviolet cutoff that is fully covariant was proposed. In ... 
Defects and Boundaries in Quantum Field Theories
(University of Waterloo, 20210729)We discuss some aspects of defects and boundaries in quantum field theories (QFTs) and their applications in revealing nonperturbative aspects of QFTs in combination with other techniques, including integrability. ... 
Design and Implementation of an Entanglement Harvesting Experiment With Superconducting Flux Qubits
(University of Waterloo, 20220516)Recent studies in relativistic quantum information have predicted that it is possible to entangle two qubits tunably coupled to the same quantum field in its vacuum state, by allowing the qubits to couple to the field ... 
Entanglement in Noninertial Frames
(University of Waterloo, 20080919)This thesis considers entanglement, an important resource for quantum information processing tasks, while taking into account the theory of relativity. Not only is this a more complete description of quantum information, ... 
Exact results in QFT: Minimal Areas and Maximal Couplings
(University of Waterloo, 20160914)This thesis is devoted to a twopronged study of nonperturbative quantum field theory. In Part I we focus on the fourdimensional super conformal $\mathcal{N}=4$ Yang Mills theory. We compute smooth Wilson loops and ... 
Explorations in the Conformal Bootstrap
(University of Waterloo, 20170719)We investigate properties of various conformally invariant quantum systems, especially from the point of view of the conformal bootstrap. First, we study twist line defects in threedimensional conformal field theories. ... 
Information propagation and entanglement generation between two UnruhDeWitt detectors
(University of Waterloo, 20100723)The setup in which two quantum systems, Alice and Bob, communicate using bosonic field quanta can be viewed as a prototype for wireless quantum communication. In this thesis we focus on the most basic case, where Alice ... 
Measurements of quantum fields and the Unruh effect: a particle detector perspective
(University of Waterloo, 20211119)This thesis is devoted to the study of detector models in quantum field theory. A detector model aims to describe a hypothetical physical situation, realistic or not, in which a measurement is performed on a quantum field ... 
On Cohomological Algebras in Supersymmetric Quantum Field Theories
(University of Waterloo, 20190816)In this thesis we compute certain supersymmetric subsectors of the algebra of observables in some QFTs and demonstrate an application of such computation in checking an instance of Holographic duality. Computing the algebra ... 
On Enumerative Structures in Quantum Field Theory
(University of Waterloo, 20200713)This thesis addresses a number of enumerative problems that arise in the context of quantum field theory and in the process of renormalization. In particular, the enumeration of rooted connected chord diagrams is further ... 
On the Application of Bandlimitation and Sampling Theory to Quantum Field Theory
(University of Waterloo, 20201007)It is widely believed that combining the uncertainty principle with gravity will lead to an effective minimum length scale. A particular challenge is to specify this scale in a coordinateindependent manner so that covariance ... 
Quantum Indefinite Spacetime: Part II
(University of Waterloo, 20180910)We adopt an operational mode of thinking to study spacetime fluctuations and their impacts on questions of quantum gravity. Particular emphasis is put on studying causal structure fluctuations. The study is guided by the ... 
Scattering Equations and SMatrices
(University of Waterloo, 20150625)We introduce a new formulation for the treelevel Smatrix in theories of massless particles. Sitting at the core of this formulation are the scattering equations, which yield a map from the kinematics of a scattering ... 
Sequences of Trees and HigherOrder Renormalization Group Equations
(University of Waterloo, 20190827)In 1998, Connes and Kreimer introduced a combinatorial Hopf algebra HCK on the vector space of forests of rooted trees that precisely explains the phenomenon of renormalization in quantum field theory. This Hopf algebra ... 
Shape & cutoff in superconducting qubits, work fluctuations in correlation creation, & critical commentary
(University of Waterloo, 20190122)Part I We apply the UnruhDeWitt model for a qubit interacting with a quantum field to a superconducting qubit. We use the flexibility of this model, as compared to the spinboson model used widely in the literature, ... 
The UnruhDeWitt Detector Model: Modified Dispersion and Nonlinear Couplings
(University of Waterloo, 20210930)In this work, we employ the UnruhDeWitt (UDW) detector model to various ends. We present applications of this relativistic detector model to quantum optics, including decoherence in optical cavities and nonlinear quantum ...