VictorJuiz/thesis huggingface dataset:
Sidorenko's conjecture, graph norms, and pseudorandomness

This thesis is primarily concerned with correlation inequalities between the number of homomorphic copies of different graphs. In particular, many of the results relate to a beautiful conjecture of Sidorenko, which roughly states that the number of copies of a bipartite graph H in a graph G is asymptotically minimised when G is the Erdos Reyni random graph.
The first part of the thesis discusses recent approaches to attack Sidorenko's conjecture. We firstly prove that every graph that admits a special kind of tree decomposition satisfies the conjecture. The proof explicitly uses information theory, which also leads to a general tool for counting fixed graphs that are decomposable in analogous ways. A recursive approach to the conjecture, using Cartesian products of graphs, will also be discussed. We show that the class of graphs that satisfy the conjecture is closed under taking Cartesian products with either trees or even cycles.
The second part studies a conjecture of Kohayakawa, Nagle, Rodl, and Schacht, which states that we have a random-like lower count for any graph H in G whenever G is locally dense, i.e., a fixed edge density is guaranteed for every large enough vertex subset. This conjecture is closely related to Sidorenko's conjecture in the sense that it is true for every bipartite graph H that satisfies Sidorenko's conjecture. We prove a partial converse, stating that if H satisfies the Kohayakawa-Nagle-Rodl-Schacht conjecture, then replacing edges of H by internally disjoint paths of length two gives an instance of Sidorenko's conjecture. We also prove some new instances of the Kohayakawa-Nagle-Rodl-Schacht conjecture by adding extra ideas to the information theoretic approach previously discussed.

Advisor: Conlon, D
Multisensory processing in the ferret auditory cortex

Our perception of events depends on the integration of information derived from different sensory modalities. Functional imaging and electrophysiological studies have shown that multisensory interactions occur even at the level of primary sensory cortices; however their functional significance remains elusive. Therefore, to explore the relationship between multisensory interactions in early auditory cortical processing areas and behaviour, we recorded activity from the auditory cortex during the performance of different auditory-visual tasks.
Ferrets were trained by positive operant-conditioning to localise auditory, visual and spatiotemporally coincident auditory-visual stimuli throughout the frontal hemifield and to categorise temporally coincident auditory-visual stimuli according to their spatial congruency. Our results show that the integration of auditory and visual cues results in significantly more accurate and faster localisation responses and that spatial information can be used to merge different sensory stimuli and resolve conflicts between them. This confirmed the ferret as a good model to explore multisensory spatial processing.
In total, 509 single units were identified in the auditory cortex of five animals, of which 16% were influenced by visual stimulation. Our results show that modulation of activity in response to changes in auditory stimulus characteristics directly relates to task performance. For example, animals were more likely to correctly localise stimuli when activity increased in the contralateral cortex and decreased in the ipsilateral cortex. The effects of visual co-stimulation were subtle, mainly suppressive and not clearly correlated with performance on either task. A population decoding analysis showed that auditory cortical activity is, however, informative about the task context, since we were able to decode task type from trials that were otherwise equivalent in terms of the stimuli presented.
Our results support the existence of multisensory interactions in early auditory processing areas, but suggest that these areas function primarily as auditory feature detectors that operate in a task-dependent manner.

Advisor: King, A
Nodal, F
Versions of Hercules in England, c. 1545-1600

This thesis traces some 'versions' of the Graeco-Roman hero and god Hercules in English writing: in early Tudor texts such as Arthur Kelton's panegyrical dynastic poems (1545, 1546), topographical and historical writing such as Holinshed's Chronicles and William Camden’s Britannia (from 1586), and the works of Sir Philip Sidney, Edmund Spenser, and several of Shakespeare’s 1590s plays. It also discusses the representation of Hercules in classical texts key to Hercules' reception in English writing, and, where appropriate, their English translations: Seneca the Younger's Hercules furens, the pseudo-Senecan Hercules Oetaeus; Roman ‘new’ comedy, and classical 'geographical' writing, such as Strabo's Geography, and Pausanias’ Description of Greece.
The thesis outlines an early modern Hercules who was a multitude of figures. This is partly because the hero is the product of a historical process of accumulation of mythological materials which, taken together, pose serious moral, generic, and narrative problems. In response, early modern understandings of Hercules often fragment him into several different figures. The thesis shows that this Herculean multiplicity is a resource for early modern writers, and demonstrates the plurality of the Herculeses present in sixteenth century English writing and translations. It also takes an inclusive view of Herculean 'appearances', by acknowledging the variety of ways of 'doing' Hercules across a range of forms: as a rhetorical utterance inherited from the hercle of Roman comedy, as a semi- 'historical' figure operating in the same legendary and geographical spaces as figures from the so-called ‘British History’, and as both a character and a proverbial subject in English dramas and entertainments.
Hercules’ early modern plurality also enables the thesis also to engage with the broader questions of what mythological allusion in texts is, and the ways in which it takes place. The thesis identifies classical geographical writing as a significant resource for information about Hercules in the early modern period, as well as mythological stories more generally. It shows how topographical texts both classical and early modern present mythological stories as local phenomena sited in particular geographical spaces, and argues that place forms a significant component of allusion to and creation of mythological narratives in early modern texts. With the help of the terms topos and locus, which suggestively blur geographical, literary, and rhetorical ‘places’, ‘place’ as used in this thesis encompasses both the geographical settings in which many mythological narratives take place, and the way in which these settings are also sites and moments of literary and mythological accumulation in texts.

Advisor: Burrow, C
Homogeneous sets in graphs and hypergraphs

A set of vertices in a graph or a hypergraph is called homogeneous if it is independent, that is it does not contain any edge, or if it is complete, that is it contains all possible pairs or subsets of it as edges. We investigate the properties of graphs and hypergraphs in two cases of imposed restrictions on the structure of their homogeneous sets.
First we study the asymptotic structure of random perfect graphs. We give a generation model which yields such graphs almost uniformly, with an additive error of e-Ω(n) in the total variation distance. We use this model to determine a number of properties of random perfect graphs, including the distribution of the stability and the clique number, the probability of containing a fixed induced subgraph, Hamiltonicity, clique-colourability, connectivity, edge colouring, and the limit of a uniformly drawn sequence of perfect graphs.
In the second part, we give a hypergraph parameter μ(H), called minor- matching number, with the property that hypergraphs H with bounded rank and minor-matching number contain a polynomially-bounded number of maximal independent sets. In the other direction, every hypergraph H contains at least 2μ(H) maximal independent sets. A number of hard hypergraph problems, including maximum-sized independent set, k-colouring and hypergraph homomorphism can be solved in polynomial time if a list with all maximal independent sets of the hypergraph is given as part of the input, and hence a family of instances with bounded minor-matching number of the input hypergraph form a new polynomial class for the problems above. The class can further be generalised by considering the maximum minor matching number of a bag in a tree decomposition as a new treewidth measure. We explain how to use this measure, defined as minor-matching treewidth, to solve hard problems and how to algorithmically construct a tree decomposition with approximate minimal width.

Advisor: Gottlob, G
McDiarmid, C
Elite female constructions of power and space in England, 1444-1541

This thesis takes an interdisciplinary approach to five residences that were commissioned and headed by noblewomen in England between the years 1444 and 1541. By focusing on the design, layout and use of domestic space, it explores how female authority was articulated through the material, spatial and social environment of the late medieval great household and its wider landscape.
The five noblewomen and sites considered in this study are as follows: Alice Chaucer, duchess of Suffolk (c.1404-75) and Ewelme Manor House (Oxfordshire); Margaret of Anjou, queen of England (1430-82) and Greenwich Palace (Kent); Margaret Beaufort, countess of Richmond and Derby (1443-1509) and Collyweston Palace (Northamptonshire); Katherine Courtenay, countess of Devon (1479-1527) and Tiverton Castle (Devon); and Margaret Pole, countess of Salisbury (1473-1541) and Warblington Castle (Hampshire). By taking a comparative approach to the principal houses of these five women, this thesis makes a new and significant contribution to scholarly discussions of gender, power and space in pre-modern England, which have until now neglected to consider the great household as a site of female authority.
Chapter one introduces the sites, and explores the geographical and social factors governing the women’s choices of those locations. Chapters two and three focus on the arrangement of outdoor and indoor space respectively, to consider whether there was a discernible gender difference in the ways in which male and female heads of household ordered space for the projection of their authority. Chapter four focuses on the representations of male and female bodies through large-scale visual media such as tapestries and wall paintings, and considers how their representation and placement within the domestic complex articulated female authority. The fifth and final chapter explores the women’s performances of their authority as household figureheads. Overall, the thesis argues that female displays of domestic authority relied on a complex interplay of masculine and feminine elements, thus challenging a prevailing notion that authoritative women in pre-modern England were merely honorary men or exceptional women, and revealing a far more nuanced reality.

Keywords: Medieval
Architecture
Landscape
Domestic Space
Gender
Advisor: Forrest, I
Mileson, S
Explaining voter turnout inequality in post-communist Eastern Europe: income inequality, institutions, and the normalization of voting

This research examines the causes of turnout inequality in post-Communist Eastern Europe, particularly focusing on how macro-level contextual factors influence voter turnout across socioeconomic groups (by education, income, occupation class). I use repeated cross-sectional survey data covering twelve countries from the collapse of communism in 1989 to the late 2000s. I show that unlike in established democracies, turnout inequality cannot be simply explained by how easy it is to vote as determined by various institutions, such as voter registration rules and ballot complexity, and neither can turnout inequality be explained by disengagement among the losers in the economic transition. Instead turnout inequality is primarily determined by the interaction between the level political motivation of individual voters, which is the product of early life political socialization, and factors related to the transition process itself, such as the waning of the initial excitement with democratic elections. Income inequality appears to indirectly discourage educated and discerning voters by reinforcing the conditions, such as the dominance of clientelistic and paternalistic parties and corruption, which render electoral choices less meaningful.

Advisor: Evans, G
Between lines: close reading, quotation, and critical style from practical criticism to queer theory

Between Lines: Close Reading, Quotation, and Critical Style from Practical Criticism to Queer Theory offers a set of theorizations and heuristics with which to investigate the history of close reading in the Anglo-American university. Working from 1920s Cambridge to the American New Criticism, and from the arrival of deconstruction at Yale to the rise of queer theory, it argues that close reading is best understood as a changing but cohering institutional style of writing that runs through twentieth-century literary criticism. In readings of I. A. Richards, William Empson, Cleanth Brooks, Paul de Man, and Eve Kosofsky Sedgwick it documents unexpected contiguities between close reading, literary modernism, twentieth-century poetics, and autobiography by positing that quotation has a formal and compositional function in critical style. Ultimately, this thesis contributes to a growing body of scholarship on the history of reading by offering the first sustained history and theory of close reading to account for the practice as it predates and outlasts the New Criticism.

Advisor: Reynolds, M
Development of xenon level instrumentation for the LZ dark matter detector

Galactical and cosmological evidence show that a quarter of the energy budget of our universe is made of collisionless, non-relativistic, and non-baryonic dark matter. Its potential coupling to standard model particles, however, has not yet been understood. One of the leading candidates - Weakly Interacting Massive Particles (WIMP) - allows the production of a dark matter relic density as observed today and couples to standard model particles at or below the weak scale.
LUX-ZEPLIN (LZ) is a future tonne-scale two-phase xenon TPC aiming to detect WIMP recoils with xenon nuclei. The experiment will begin WIMP search data-taking in 2020 at the Sanford Underground Research Facility (SURF) in Lead, South Dakota and has a projected sensitivity of 3 × 10-48 cm2 or better in probing a 40 GeV/c2 WIMP. The main observables of particle interactions in LZ are the primary scintillation (S1) and secondary scintillation (S2). However, optimising and achieving a stable S2 signal in such a tonne-scale TPC is non-trivial. Effects from the structural design of the S2 production region (top-corner structure), TPC tilt, and the xenon circulation system requires precise monitoring of the liquid surface. Such monitoring is achieved by the capacitive liquid level sensors developed within this thesis. The sensors are strategically placed to ensure that nonuniformity of the S2 signal due to the effects can be understood and corrected.
In this thesis, the development of a monitoring system designed to optimise the quality of the S2 signal, based on the capacitive level sensors is discussed. A design of the electronics scheme based on a differential measurement allows femtofarad precision measurement of sensor’s capacitance at picofarad level, even in the presence of cable capacitance at nanofarad level. A systematic study of the response of such a sensor to LXe and the application of the precision level sensors to two-phase TPC was carried out. Findings of intrinsic influences from LXe artefacts and LXe dielectric constant variation with its saturated temperature are identified; the result on the application of the sensors contributes to the designs of LZ circulation and the top-corner region. The final LZ level sensors show an artefact-free liquid level measurement and a 12 μm precision in measuring liquid nitrogen level (projection for LXe: &Tilde; 9 μm) over a 20 mm measurement range.

Keywords: xenon tpc
dark matter
level sensor
Advisor: Kraus, H
A bifurcation analysis of models of liquid crystals

In this thesis we provide a deeper insight into the fundamental phase transition between isotropic and nematic states of liquid crystals. In particular, we focus on the problem of classifying all minimising states of the Onsager free-energy functional in three dimensions, a problem which has drawn a lot of attention since 1949. We study the bifurcation diagram of the Onsager free-energy functional for liquid crystals with orientation parameter on the sphere. In particular, we concentrate on the bifurcations from the isotropic solution for a general class of two-body interaction potentials including the Onsager kernel. Reformulating the problem as a non-linear eigenvalue problem for the kernel operator, we prove that spherical harmonics are the corresponding eigenfunctions and we present a direct relationship between the coefficients of the Taylor expansion of this class of interaction potentials and their eigenvalues. We find explicit expressions for all bifurcation points corresponding to bifurcations from the isotropic state of the Onsager free-energy functional equipped with the Onsager interaction potential. A substantial amount of our analysis is based on the use of spherical harmonics and a special algorithm for computing expansions of products of spherical harmonics in terms of spherical harmonics is presented. Using a Lyapunov-Schmidt reduction, we derive a bifurcation equation depending on five state variables. The dimension of this state space is further reduced to two dimensions by using the rotational symmetry of the problem and the invariant theory of groups. On the basis of these results, we show that the first bifurcation from the isotropic state of the Onsager interaction potential is a transcritical bifurcation and that the corresponding solution is uniaxial. In addition, we prove some global properties of the bifurcation diagram such as the fact that the trivial solution is the unique local minimiser if the bifurcation parameter is high, that it is not a local minimiser if the bifurcation parameter is small, the boundedness of all equilibria of the functional and that the bifurcation branches are either unbounded or that they meet another bifurcation branch.

Advisor: Ball, J
Query answering in distributed RDF databases

To simplify data integration and exchange, modern applications often represent their data using the Resource Description Framework (RDF). As the amount of the available data keeps increasing, many RDF datasets cannot be processed using centralised RDF stores. A common solution is to distribute RDF data in a cluster of shared-nothing servers, and to query the data using a distributed query algorithm. Existing approaches typically use a variant of the data exchange operator to shuffle partial query answers between servers and thus ensure that every query answer is produced. Decisions as to when and where to shuffle the data are usually made statically—that is, at query compile time. In this thesis, we argue that such approaches can miss opportunities for local computation and thus incur considerable overheads. Moreover, we present a novel distributed query evaluation algorithm for RDF based on dynamic data exchange, where all computation that can be done locally is guaranteed to be performed on a single server. Our approach can successfully process any query even if the memory available at each server is bounded, and we argue that this is critical in distributed systems where intermediate results can easily exceed the capacity of each server. We also present a new query planning approach that balances the cost of communication against the cost of local processing at each server, as well as a new approach to partitioning RDF data that aims to increase locality in each server. We have implemented our approach in the well-known RDFox data store, and our empirical evaluation suggests that our techniques can outperform the state of the art by orders of magnitude in terms of query evaluation times, network communication, and memory use.

Advisor: Horrocks, I
Motik, B
The dramatic role of astronomy in early modern drama

By examining five types of astronomical and celestial phenomena—comets, constellations, the zodiac, planets, and the music of the spheres—this thesis posits not only that early modern dramatists were influenced by established and emerging natural philosophy as habits of thought that manifested in their writing, but also that astronomical phenomena operate within the drama, performance, and in the theatre as elements for creating and developing a distinctly spatial dramaturgy. Using theories from the spatial turn, this thesis maps the positions, edges, disturbances, and motions of celestial properties within the imaginary and physical space of early modern drama and theatre. It argues that the case study plays examined within this thesis demonstrate a period-wide engagement, rather than an authorial-, company-, theatre-, or even genre-specific practice. Dramatists developed techniques using astronomical phenomena as dramatic methods that occasionally underscored early modern astronomical thought. However, in many cases constructed plots, characters, visual and sound effects, and movements transgressed astronomical expectations. Dramatists broke down constellations, inserted new stars in the heavens, created zodiacal females, launched pyrotechnical comets, moved planets unexpectedly across the stage, and played (and refrained from playing) celestial "music" for the audience. Recognising composite and often contradictory astronomical constructions within the drama, this thesis moves the critical discussion away from an intellectual history of natural philosophy and gravitates toward an active astronomical dramaturgy.

Keywords: early modern
zodiac
Shakespeare
almanac
armillary sphere
bodies
spatial turn
spatial theory
astronomy
drama
globe
constellations
planets
comets
space
celestial
Advisor: Smith, E