VictorJuiz/thesis huggingface dataset:
Local moment phases in quantum impurity problems

This thesis considers quantum impurity models that exhibit a quantum phase transition (QPT) between a Fermi liquid strong coupling (SC) phase, and a doubly-degenerate non-Fermi liquid local moment (LM) phase. We focus on what can be said from exact analytic arguments about the LM phase of these models, where the system is characterized by an SU(2) spin degree of freedom in the entire system.
Conventional perturbation theory about the non-interacting limit does not hold in the non-Fermi liquid LM phase. We circumvent this problem by reformulating the perturbation theory using a so-called `two self-energy' (TSE) description, where the two self-energies may be expressed as functional derivatives of the Luttinger-Ward functional.
One particular paradigmatic model that possesses a QPT between SC and LM phases is the pseudogap Anderson impurity model (PAIM). We use infinite-order perturbation theory in the interaction, U, to self-consistently deduce the exact low-energy forms of both the self-energies and propagators in each of the distinct phases of the model. We analyse the behaviour of the model approaching the QPT from each phase, focusing on the scaling of the zero-field single-particle dynamics using both analytical arguments and detailed numerical renormalization group (NRG) calculations.
We also apply two `conserving' approximations to the PAIM. First, second-order self-consistent perturbation theory and second, the fluctuation exchange approximation (FLEX). Within the FLEX approximation we develop a numerical algorithm capable of self-consistently and coherently describing the QPT coming from both distinct phases.
Finally, we consider a range of static spin susceptibilities that each probe the underlying QPT in response to coupling to a magnetic field.

Keywords: non-Fermi liquid
quantum phase transition
Fluctuation exchange approximation
diagrammatic many-body theory
magnetic field
local moment phase
Kondo physics
Luttinger
quantum impurity physics
Advisor: Logan, DE
Subject and person

The main aim of this thesis is to investigate the relations between the topics of self-reference and personal identity and to demonstrate that, and how, certain misconceived views concerning self-reference have influenced the interpretation of various 'thought-experiments' cited in recent discussions of personal identity.
The problem posed by personal identity, I argue, is not so much an ontological problem concerning the special nature of a particular kind of substances (i.e. persons), but consists rather in the fact that I (and all other persons) are tempted to take our identity to be governed by a criterion of identity different from the criterion governing the identity of all other kinds of concrete particulars (namely spatio-temporal continuity). I argue that this temptation stems from the possibility of adopting a first-person point of view towards personal identity.
This possibility is shown to be intimately connected with a person's ability to refer to himself-as-subject (i.e. without the application of any criteria of his identity). This particular kind of self-reference displays certain epistemic idiosyncracies which make us susceptible to certain systematic illusions with regard to the nature of persons and of personal identity over time. Following Kant, I call these misconceptions 'paralogistic illusions', and I try to show that,and how, various thought-experiments envisaging a person's putative 'body-change' draw their persuasive strength from these illusions. Kant's distinction between a purely 'logical' and an ontological, or substantial, understanding of the 'identity of the subject' is shown to be central to a dissolution of the illusion as well as to the solution of various philosophical conundrums concerning (particular kinds of) memory and imagination.
The view of persons and their identity that emerges from the discussion differs sharply from both a 'Simple View' and a 'Reductionist View' of personal identity. Persons, it will appear, are a functionally definable sub-class of animals, and - given the fulfilment of certain background-conditions ~ a person's numerical identity over time consists in the spatio-temporal continuity of his living body.
The concept of discipline

Discipline was an enduring concept in the works of John Milton (1608-1674), yet its meaning shifted over the course of his career: initially he held that it denoted ecclesiastical order, but gradually he turned to representing it as self-willed pious action. My thesis examines this transformation by analysing Milton’s complex engagement in two distinct periods: the 1640s and the 1660s-70s. In Of Reformation (1641), Milton echoed popular contemporary demands for a reformation of church discipline, but also asserted through radical literary experimentation that poetry could discipline the nation too (Chapter 1). Reflecting his dislike for intolerant Presbyterians in Parliament and the Westminster Assembly, the two versions of The Doctrine and Discipline of Divorce (1643 and 1644) reconsider discipline as a moral imperative for all men, rooted in domestic liberty (Chapter 2). Although written long after this period, the long poetry that Milton composed after the Restoration reveals his continued interrogation of the concept. The invocations of the term ‘discipline’ by Milton’s angels in Paradise Lost (1667) sought to encourage dissenting readers to faithfulness and co-operation (Chapter 3). Paradise Regained and Samson Agonistes (1671) advance the concept in the language of ‘piety,’ emphasising that ‘pious hearts’ are the precondition for godly action in opposition to contemporary Anglican ‘holy living’ (Chapter 4). In analysing Milton’s shifting concept of discipline, my thesis contributes to scholarship by showing his sensitivity to contemporary mainstream religious ideas, outlining the Christian—as opposed to republican or Stoic—notions of praxis that informed his ethics, and emphasising the disciplinary aspect of his doctrinal thought. Overall, it holds that in discipline, as word and concept, Milton expressed his faith in the capacity of writing to change its reader, morally and spiritually.

Keywords: Smectymnuus
Poetry
Paradise Lost
Paradise Regained
Piety
Rhetoric
ethics
Church
Colasterion
ecclesiology
The Doctrine and Discipline of Divorce
Augustine
Of Reformation
Milton
Discipline
Samson Agonistes
Advisor: Achinstein, S
The American civil war in twentieth-century Britain: political, military, intellectual and popular legacies

This thesis explores the continuous British interest in the American Civil War from the war’s end to the late twentieth century and the British utilisation of the conflict at home and in the Atlantic arena. Contributing to the limited, yet burgeoning literature on the subject, this study emphasises the independent agency of both the Civil War and its British interpreters. It thus rejects a simplistic depiction of British adoption of American culture and applies a more sophisticated methodology that accounts for the active, versatile and autonomous British use of complex foreign images. This enables a meaningful analysis of the Civil War’s place and role in modern British culture.
The thesis examines the British fascination with the conflict as reflected in four facets: politics, military thought, academe and popular culture. Additionally, it takes a transatlantic perspective and explores how Britons’ view of the United States has influenced their understanding of the Civil War. This study thus provides a first comprehensive and coherent overview as well as a nuanced picture of the American conflict as it travelled across the Atlantic from a historically distanced perspective.
The thesis reveals that the Civil War achieved unique prominence in British culture and that this British fascination with the war was part of a greater transatlantic encounter between an epic American affair and sophisticated British interpreters. Accordingly, the two main questions underpinning this study are ‘why were the British particularly interested in the Civil War?’ and, following directly on that path, ‘how did Britons use the war both at home and in the transatlantic sphere?’ Answering these questions further establishes the war’s prominence in British culture and explores the character of the British encounter with the conflict. In so doing, it contributes to our understanding of the Civil War’s global impact and casts another light on Anglo-American relations.

Keywords: Anglo-American relations
memory
American civil war
transatlantic cultural exchanges
Britain
Advisor: Goldman, L
Bayesian statistical models of shape and appearance for subcortical brain segmentation

Our motivation is to develop an automated technique for the segmentation of sub-cortical human brain structures from MR images. To this purpose, models of shape-and-appearance are constructed and fit to new image data. The statistical models are trained from 317 manually labelled T1-weighted MR images. Shape is modelled using a surface-based point distribution model (PDM) such that the shape space is constrained to the linear combination of the mean shape and eigenvectors of the vertex coordinates. In addition, to model intensity at the structural boundary, intensities are sampled along the surface normal from the underlying image. We propose a novel Bayesian appearance model whereby the relationship between shape and intensity are modelled via the conditional distribution of intensity given shape. Our fully probabilistic approach eliminates the need for arbitrary weightings between shape and intensity as well as for tuning parameters that specify the relative contribution between the use of shape constraints and intensity information. Leave-one-out cross-validation is used to validate the model and fitting for 17 structures.
The PDM for shape requires surface parameterizations of the volumetric, manual labels such that vertices retain a one-to-one correspondence across the training subjects. Surface parameterizations with correspondence are generated through the use of deformable models under constraints that embed the correspondence criterion within the deformation process. A novel force that favours equal-area triangles throughout the mesh is introduced. The force adds stability to the mesh such that minimal smoothing or within-surface motion is required.
The use of the PDM for segmentation across a series of subjects results in a set surfaces that retain point correspondence. The correspondence facilitates landmark-based shape analysis. Amongst other metrics, vertex-wise multivariate statistics and discriminant analysis are used to investigate local and global size and shape differences between groups. The model is fit, and shape analysis is applied to two clinical datasets.

Keywords: image processing
segmentation
MRI
statistical shape models
Advisor: Smith, SM
Jenkinson, M
The development of an in-situ UV ablation GC-irms technique for the analysis of oxygen isotopes in metamorphic minerals, and its application to polymetamorphic schists from Western Massachusetts, U.S.A

This thesis describes an attempt to develop a pioneering method for the analysis of oxygen isotopes in metamorphic rocks. This technique is then applied to a suite of metapelites from Massachusetts, U.S.A. with the aim of investigating metamorphic history.
The study of oxygen isotopes is a rapid and efficient way of deciphering the reaction history of a metamorphic rock, and they are particularly useful for quantifying the role of fluids during metamorphism. Technological advances have given the opportunity to develop a new laser fluorination facility capable of in-situ oxygen isotope analysis on the 100μm scale. The use of UV laser ablation coupled with helium carrier flow and isotope ratio mass spectrometry gives the potential for liberation, transfer and analysis of nanomoles of oxygen.
This analytical technique is developed herein, and applied to garnets from high alumina metapelites of the Hoosac Schist of Western Massachusetts. These large garnets contain concentric unconformity textures which are attributed to at least two metamorphic events. Core-rim zoning profiles from three Hoosac garnets has been accomplished.
Metamorphic modelling in the complex chemical system Na2O-CaO-MnO-K2O-FeO-MgO-Al2O3- SiO2-H2O has yielded P-T estimates for garnet cores of 520°C and 8.5 kbar, and rims at 590°C and 8-10kbar. Within this framework, a new approach enables calculation of oxygen isotope shifts with reaction progress in the presence of a non-equilibrium fluid. Fitted profiles from the Hoosac garnets imply prograde core growth during inflow of external low-δ18O fluid, and calculations suggest a minimum time integrated fluid flux for the first garnet growth event of the order of 0.2 cm3/cm2, some four to five orders of magnitude less than other New England studies.

Advisor: Waters, D
Young, E
Dave Waters and Ed Young
Development of advanced three-dimensional tumour models for anti-cancer drug testing

Animal testing is still the common method to test the efficacy of new drugs, but tissue engineered in vitro models are becoming more acceptable for replacing and reducing animal testing in anti-cancer drug screening by developing in vitro three-dimensional (3D) tumour models for anti-cancer drug testing. In this study, three-dimensional (3D) culture methods were developed to mimic the tumour microenvironment. 3D culturing is to seed, maintain and expand cultured cells in three-dimensional space, in contrast to the traditional two-dimensional (2D) method in which the cells attach to the bottom of culture containers as monolayers. To mimic the intercellular interplay for tumour study, cell co-culture was applied. In this thesis, perfusion culture showed a better homeostasis for 3D tumour model growth over 17 days, with a more controllable working platform and a more reliable response-dose correlation for data interpretation. In the Matrigel sandwich system, the co-culture of breast cancer cells and endothelial cells demonstrated the morphology featuring a vascular network and tumour structures, with the thickness of the three-dimensional structure around 100µm and tubule length 200-400 µm, and maintained for 10 days. The comparisons studies between Matrigel sandwich and other methods suggest that though not fully characterised, Matrigel is still a valuable scaffold choice for developing co-culture 3D tumour model. Finally, the combination of perfusion and co-culture showed the potential of applying this model in angiogenesis assay, with a drug response profile combining cell viability and morphology to mimic in vivo tumour physiology.

Keywords: colorectal cancer cells
endothelial cells
three-dimensional culture
co-culture tumour model
breast cancer cells
anti-cancer drug testing
perfusion
Advisor: Cui, Z
Ye, C
Physical and numerical modelling of grouted nails in clay

The research described in this thesis focussed on the bond resistance of grouted soil nails in clay. Physical modelling took the form of large scale element tests in the laboratory of drilled and grouted nails in a stiff clay. Nails were installed under different boundary stresses; testing was conducted at different constant rates of pull-out and also under sustained load conditions. Observed behaviour was compared with that predicted by measurements of interface shear resistance obtained in a conventional shear box. Numerical modelling was carried out in an attempt to improve understanding of the effects of installation processes on nail performance, and to investigate the trends in behaviour observed during laboratory tests. For this purpose, a one-dimensional finite element computer program was developed to include the effects of consolidation and the out-of-plane soil displacements associated with nail axial loading. The physical modelling showed that the loading rate has a significant effect on bond resistance. This has consequences for the interpretation of data from constant rate of displacement pull-out testing, the conventional method of verifying bond resistance in the field. It is suggested that this type of testing is inappropriate in low permeability soils, because capillary suctions develop which lead to increased bond resistance. Results from laboratory sustained load tests show that lower values of bond resistance are mobilised under the static load conditions more likely to exist in a real soil nailed structure. The numerical modelling confirms the behaviour observed during the laboratory tests, and shows that the mechanisms by which bond is mobilised are complex, depending critically on the dilation and consolidation characteristics of the soil. Nail installation procedures are modelled, and grout pressures are shown to strongly influence bond resistance. Interface tests show trends in behaviour similar to those observed during pull-out testing. However, difficulties exist in the qualitative use of interface test data to predict nail bond resistance.

Keywords: soil nailing
clay
Advisor: Burd, H
Milligan, G
The token-token identity-theory and recent theories of reference

This thesis investigates a specific kind of criticism of the token-token identity-theory. This criticism is based on recent theories of reference. In the Introduction I argue that more than Davidson's three premisses is needed to establish that mental events are identical to physical events. One needs to invoke principles about what constitutes event-identity.
In Part 1 I discuss event-identities. I lay down the constraints an adequate theory of event-identity must satisfy, and criticise the major theories in the literature. I suggest an alternative view, which I defend against some recent proposals. I end Part 1 by exploring a view which takes seriously the possibility of constitution-relations between events.
In Parts 2 and 3 I discuss whether the identity-theory can be defended. Part 2 discusses sensations, and I concentrate on S. Kripke's arguments against the identity-view. I distinguish two versions of Kripke's argument, one epistemic, and one metaphysical. The epistemic version of the argument presupposes Kripke's views on content, but fails by its own standards. The metaphysical version is shown to be weak and implausible.
Part 3 discusses cognitive events, and concentrates on de re beliefs. I produce an argument which apparently defeats the identity-view. I elaborate two main strategies in defence of the identity-theory. I argue that given a theory of de re beliefs or singular thoughts like G. Evans's, the theory of event-identities I have developed, and some plausible further premisses, the identity-theory seems to be defeated. A reasonable interpretation of this result is to view it as an argument for constitution-relations between mental and physical events. I return to the view I introduced in part 1, and conclude that the token-token identity-theory should probably be replaced by this constitution-view if theories of de re beliefs are accepted.
Quixotes, dreamers and imaginists

The following study is an examination of the deluded heroine in the novel between 1740 and 1820. Through close readings of fiction by Samuel Richardson, Charlotte Lennox, Frances Burney, Charlotte Smith, Ann Radcliffe and Jane Austen, and discussion of relevant works by other authors of the period, the reasons for the prevalence of this figure are considered. The thesis proposes that this choice of protagonist enabled the exploration of a number of the issues that most concerned contemporary novelists.
Principal amongst these was the question of identification between reader and literary protagonist. Throughout this period authors engaged in attempts to develop and control the audience's response. The desired end was the "improvement" of readers by the experience of the situations, mistakes and trials of the text's central characters. Increasingly though, the unpredictable and fluctuating nature of the readers' reactions was recognised. The result was a conflict between "text as instruction", the moral education that authors professed to offer, and "text as fiction", the attractions of story, adventure and imagination which were ostensibly valued only as they brought readers to works intended to improve them.
The connection of the latter to romance was a further source of tension. The establishment of the novel as a model for life was premised on claims to probability, but aspects of the texts remained which worked against mimetic representation. These oppositions explain the contemporary popularity of the quixotic narrative, since the quixote both enacted the "madness" of excessive imaginative involvement with literature and could also be shown learning to make a "correct" choice of genre for reading. The strategies that can be observed within the quixote novel have a wider application when they are considered alongside the patterns of imitation, influence and parody which characterise the fiction of the period. In order to examine these features, the thesis includes an analysis of two important literary dialogues: those between Richardson and Lennox, and between Radcliffe and Austen.
My focus on the heroine acknowledges the significance of gender in the period's fiction. Created by both female and male authors, such figures could be either exemplary models or quixotic warnings. They nevertheless share an experience of delusion followed by enlightenment constructed in order to benefit the "reading Misses" following their adventures. Unlike much recent criticism, however, my concern is more with the author as creative artist, text as literary process and reader as imaginative participant, than with historical or sociological contexts.
Diversity strategies for MIMO communication systems

This thesis proposes a joint spatial diversity scheme in MIMO systems in order to improve the transmission reliability of the wireless links, thereby to extend the transmission range and increase the information throughput. Cyclic delay diversity (CDD) and antenna selection are employed here for their low complexity, high flexibility, no spectrum efficiency reduction and high compatibility with many existing standards. A bit error performance bound for CDD system with orthogonal frequency division multiplexing and convolutional coding in multipath Rayleigh fading channel is generated, which renders a fundamental understanding of the mechanism of CDD and can be used instructively for CDD system design. A transmit cyclic delay diversity and receive antenna selection (TCDD/RAS) system is proposed here to achieve a performance gain with lower additional complexity and no data rate reduction compared with a transmit orthogonal space-time block coding (OSTBC) system, which is combined with the optimum receive antenna selection scheme. A hybrid system with both OSTBC and CDD in the transmitter and antenna selection in the receiver is also derived to avoid the high complexity requirement and data rate degradation of the OSTBC system as well as the performance loss of the CDD system. A receive antenna selection criterion for the TCDD/RAS system based on the previous performance analysis results is defined, however it demands high computational complexity. Therefore a much simpler and faster selection rule, named maximum minimum post-processing SNR criterion, is generated for the TCDD/RAS system in flat fading channels and another maximum group minimum post-processing SNR selection principle is developed in frequency selective channels. Both of these two selection rules achieve higher diversity gains with lower additional complexity compared with the traditional norm and capacity selection rules. Two relay systems embedded with the TCDD/RAS scheme are also constructed: the MIMO relay system and the cooperative relay system. The joint diversity scheme in the MIMO relay system obtains a higher diversity gain than in the cooperative relay system. Moreover, these two relay systems could be combined to a system with multiple cooperative relay nodes on which multiple antennas are deployed depending on the practical requirement in the future wireless communication systems.

Keywords: MGMP-SNR
OFDM
CDD
STBC
MIMO
MMP-SNR
Advisor: Edwards, D