Amplitudes at Infinity

We investigate the asymptotically large loop-momentum behavior of multi-loop amplitudes in maximally supersymmetric quantum field theories in four dimensions. We check residue-theorem identities among color-dressed leading singularities in $\mathcal{N}=4$ supersymmetric Yang-Mills theory to demonstrate the absence of poles at infinity of all MHV amplitudes through three loops. Considering the same test for $\mathcal{N}=8$ supergravity leads us to discover that this theory does support non-vanishing residues at infinity starting at two loops, and the degree of these poles grow arbitrarily with multiplicity. This causes a tension between simultaneously manifesting ultraviolet finiteness---which would be automatic in a representation obtained by color-kinematic duality---and gauge invariance---which would follow from unitarity-based methods.Comment: 4+1+1 pages; 15 figures; details provided in ancillary Mathematica file

Simulation of ventilation distribution and gas transport during oscillatory ventilation

High frequency oscillatory ventilation (HFOV) relies on low tidal volumes cycled at supraphysiologic rates, producing fundamentally different mechanisms for gas transport and exchange compared to conventional mechanical ventilation. Despite the appeal of using low tidal volumes to mitigate the risks of ventilator- induced lung injury (VILI), HFOV does not improve mortality in most clinical applications. One possible explanation for this is that HFOV distributes flows throughout the lung in a non-uniform and frequency-dependent manner, especially in the presence of mechanical heterogeneity. This thesis is a systematic investigation of the relationship between carbon dioxide elimination and frequency content during oscillatory ventilation, with emphasis on the frequency- dependent effects of mechanical heterogeneity and various gas transport mechanisms. A computational model consisting of an anatomically-structured airway network was used to simulate ventilation distribution and gas exchange in a canine lung. These simulations were validated against theoretical predictions and experimental data for eucapnic oscillatory ventilation. The model was also used to assess the impact of mechanical heterogeneity on ventilation distribution and gas transport. Simulations demonstrated a critical transition at the resonant frequency, above which the ventilation patterns became spatially clustered and frequency-dependent. Finally, the model demonstrated that pairs of oscillatory frequencies could yield eucapnic conditions with less potential for VILI compared to traditional single frequency HFOV. These results illustrate the importance of frequency selection in managing the distribution of ventilation and gas transport in the heterogeneous lung, and suggest that the frequency content in oscillatory waveforms may be optimized to achieve eucapnic gas exchange using less injurious ventilation.2017-10-27T00:00:00

Post-9/11 SF Films: Terrorism, Warfare, and Dystopia

The 9/11 event has had a profound impact on all forms of contemporary narratives. After 9/11, the Bush Administration waged The War on Terror as a way to bring about the imperialist pride that the United States once maintained before Vietnam and to restore what Tom Englehardt refers to as “victory culture.” The United States government and its military have utilized the media to construct a national purpose since 9/11: a purpose largely understood as a mission to combat and eradicate terrorism as well as to police third world nations. This thesis examines post-9/11 SF films, such as The Dark Knight (2008), Revenge of the Sith (2005) and The Avengers (2012), for their ability to examine these cultural issues without directly indicting the U.S. and its military. Post- 9/11 SF films express three distinct anxieties that are common to the American people and their nation: terrorism, warfare, and dystopia. In conjunction with these cultural anxieties, these films convey a loss of both national identity and individual identity through a lack of freedom, democracy, and symbolic physically flawed characters. While these films vary in subject and intent, SF films remain a lens through which to explore important contemporary issues and to express the hope for a better future

Tools of Horror: Servants in Gothic Novel

The servants within 18th- and 19th-century English literature play an undoubtedly vital role within everyday life. Elizabeth Langland highlights this point in her discussion of the middle class: “Running the middle-class household, which by definition included at least one servant, was an exercise in class management, a process both inscribed and revealed in the Victorian novel” (291). In Victorian England, especially, class and rank were everything. While during the Romantic period servants were common, rising concerns for their role in the household becomes more apparent during the Victorian Era. Gothic novelists take their concerns for these domestic issues and use the servants as easy targets to become scapegoats in the novel themselves. In both the The Castle of Otranto and Wuthering Heights, the fear of exploited power and class position leads the authors to use servants as ignorant tools in order to heighten the suspense and terror, thereby exhibiting the concerns for their role in society. Nelly Dean in Wuthering Heights, for instance, interferes with dealings between the inhabitants of Thrushcross Grange and Wuthering Heights so much that some critics see her as the “villain.” When she has a chance to stop Isabella from entering Wuthering Heights, she neglects her duty and instead follows her inside. Other servants, such as Joseph, increase the terror by releasing the dogs to attack Lockwood as he leaves Wuthering Heights. In The Castle of Otranto the servants, especially Bianca, enhance the terror by telling of the horrific sights they encounter, like the giant hand. While it is true that they manage daily household duties and often care for children, they also have the opportunity to abuse their power, which causes anxiety among the ruling classes. [Page 1

In Spite of Pragmatics: The Pursuit of Both/And for Integrated Architectural Solutions

Architectural design studios that are tasked with the responsibility of addressing and demonstrating NAAB criteria for Integrated Architectural Solutions (IAS, formerly Comprehensive Design) can, by their very nature, become venues for promoting strict pragmatism. By its very definition pragmatism is primarily concerned with relating to matters of fact or practical affairs often to the exclusion of intellectual or artistic endeavors - thus setting up a preferential condition by which project proposals may be evaluated. Pursuits to such an end, although perhaps expressing a certain level of competency and technocratic ability, more often than not fall short of higher architectural aims. The challenge being that good/great design is difficult to define through a set of predetermined instructions, formalized processes, or applied systems. For example, utilizing a highly-sophisticated filtration and distribution system for capturing rainwater to be used in gray-water systems throughout a project does not automatically define the project as exceptional. On the contrary, the pursuit of the exceptional is one that is extremely difficult to define because it is often unspoken. For the Indian architect Balkrishna Doshi the architectural endeavor is: a search for the unknown which (is) not known, neither do I know how it will manifest. It begins somewhere, it ends somewhere, and in that process, I grow and the work grows. And we both grow together.1 Because of its elusiveness, the true value of a proposal is often only revealed at a much later time and in unexpected ways

Prescriptive Unitarity

We introduce a prescriptive approach to generalized unitarity, resulting in a strictly-diagonal basis of loop integrands with coefficients given by specifically-tailored residues in field theory. We illustrate the power of this strategy in the case of planar, maximally supersymmetric Yang-Mills theory (SYM), where we construct closed-form representations of all (n-point N^kMHV) scattering amplitudes through three loops. The prescriptive approach contrasts with the ordinary description of unitarity-based methods by avoiding any need for linear algebra to determine integrand coefficients. We describe this approach in general terms as it should have applications to many quantum field theories, including those without planarity, supersymmetry, or massless spectra defined in any number of dimensions

Wandering Imperialism: Nationalism, Hybridity, and Identity in the Matter of Britain

This dissertation examines how the cultural and political effects of colonial subjugation and conquest shape ideological constructions of nation and empire within the Matter of Britain. Combining the theories of ethno-symbolism and imperium studies, I challenge pre-existing notions of developing nationalism as a modern phenomenon. I argue that these Arthurian texts engage in identity exploration and construction by exploring England’s imperial relations with Scotland and Wales, and in doing so, lays the foundation for a new idealized “British” (rather than English) nationalism that unifies the various peoples of the British Isles. My work takes a broad view of Arthurian romance in addressing five major texts across the late fourteenth / early fifteenth centuries: Sir Gawain and the Green Knight, Awntyrs off Arthur, Sir Gawain and the Carle of Carlisle, the Alliterative Morte Arthure, and Malory’s Le Morte d’Arthur. I begin by examining how borderland spaces shape ethnic identity and collective cultural memory. The last part of my analysis considers how English ethnic identity is contingent on its connection to Rome as both a physical homeland and an idealized imperial space. I conclude by considering how imagined ethnic solidarity, whether in a medieval or modern context, ignores the realities of English as a culturally hybrid ethnicity

Building Bases of Loop Integrands

We describe a systematic approach to the construction of loop-integrand bases at arbitrary loop-order, sufficient for the representation of general quantum field theories. We provide a graph-theoretic definition of `power-counting' for multi-loop integrands beyond the planar limit, and show how this can be used to organize bases according to ultraviolet behavior. This allows amplitude integrands to be constructed iteratively. We illustrate these ideas with concrete applications. In particular, we describe complete integrand bases at two loops sufficient to represent arbitrary-multiplicity amplitudes in four (or fewer) dimensions in any massless quantum field theory with the ultraviolet behavior of the Standard Model or better. We also comment on possible extensions of our framework to arbitrary (including regulated) numbers of dimensions, and to theories with arbitrary mass spectra and charges. At three loops, we describe a basis sufficient to capture all `leading-(transcendental-)weight' contributions of any four-dimensional quantum theory; for maximally supersymmetric Yang-Mills theory, this basis should be sufficient to represent all scattering amplitude integrands in the theory---for generic helicities and arbitrary multiplicity.Comment: 76 pages, 6 tables, hundreds of figures. Ancillary file includes our results for three loop