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Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 184-198).

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in ful lment of the requirements for the degree of Master of Science. June 29, 2017. / In this dissertation we explore the connection between entanglement and geometry. Recent work in the AdS/CFT correspondence has uncovered fascinating connections between quantum information and geometry, suggesting that entanglement in the CFT results in the emergence of spacetime in the bulk . We work in the 1/2 BPS sector of the duality between N = 4 super Yang Mills on R x S3 and IIB string theory on AdS5 S5. We aim to test this connection by calculating the Renyi entropies in the presence of 1/2 BPS operators heavy enough to deform the background geometry. This allows us to calculate the entanglement of these operators via the replica trick. The Ryu-Takayanagi formula relates this calculation to a minimal surface in the dual supergravity geometry, thus allowing us to observe how the boundary entanglement affects the bulk spacetime. We build a formula to calculate correlation functions of 1/2 BPS operators on the Riemann sheet that arises from the replica trick. This is a recursive formula based on group theory techniques. We demonstrate how the formula works for light operators and discuss how it can be generalised to include heavy operators by considering symmetric groups of higher order. / LG2018

Abstract not available

This thesis investigates the relationship between communication and place, and the informational environment it forms. The thesis takes as its object of analysis signage, and examines signage as an implaced medium of communication. / In this work communication, including its practices and technologies, is treated as a dynamic ritual formed by the marking, naming, connecting, and interpreting the environment in the process of wayfinding. Such an approach underscores the inherent duality of communication: its manifestations framed by transmission and ritual; its boundedness by both space and time; and its expression in both mobile and fixed (implaced) media. The thesis thus shifts the disciplinary discourse from the usual text- and language-based focus to a more comprehensive focus that encompasses architectural and infrastructural environments and the grounding action of physical presences. Through its focus on the navigational aspects of communication, and framing by such concepts as wayfinding and signposting, the thesis shows how we can reconfigure the notion of the visual to include the embodied, experiential, and implaced. This in turn can help us gain a new perspective on the changing nature of text, image, representation, information and reality. / The thesis argues that as the themes of orientation, navigation, and interface grow alongside the new communication technologies, they make it important to attend to the original mediating role of the built environment and the navigational dimensions of place. It is here, within our foundational spatial orientation and wayfinding, that we turn for the metaphors, conceptual structures, and grounding as we chart our ways through the emerging informational environments. / In examining signage as a system of interfaces used in negotiating informational environments, as way-markers in a process of wayfinding, the thesis demonstrates the ways in which the concepts of wayfinding and navigation have become consequential to communication scholarship. It proposes that fruitful cues for the theorising and understanding of emerging informational realms can be drawn from the communicative dimensions of the most familiar immersive environments and their related practices: the physical spaces and built environments that we inhabit and negotiate daily.

This thesis is concerned with an investigation of twistorial structures present in curved Lorentzian space-times. Chapter 1 introduces the basic definitions and some theorems that will be used later in the text. Chapter 2 investigates generalised connections that arise in twister theory. First the Cartan con-formal connection is studied, and some of the geometry underlying it is shown to be that used by Fefferman and Graham C133. Also a condition that a space-time is conformal to vacuum is given. Secondly the theory of the Chern connection associated to a C.R. manifold is developed in such a way as to make the calculation of the connection associated to a twistor C.R. manifold straight forward. A new proof of the Chern theorem of existence and uniqueness is given. The Chern connection of a twistor C.R. manifold is then calculated, and discussed. In particular S-dimensionai C.R. manifolds arising as twistor C.R. manifolds are characterised. Canonical structures peculiar to the twister case are discussed. Applications of C.R. manifold theory to algebraically special space-times are suggested. Chapter three analyses how various twistorial structures behave in linearised general relativity. First, deformations of the space of complex null geodesies corresponding to variations of the conformal structure of space-time are shown to be generated by hami1tonians. Those that correspond to variations in the metric satisfying the field equations are given, along with hamiltonians corresponding to different fields and field equations. Beneralisations to nonlinear equations are discussed. These ideas are applied to hypersurface twisters in linearised theory, using fiat hypersurfaces and Cech cohoeology. Expressions are obtained for the deformation of the complex structure of the spaces and their evolution. The results are generalised to non flat hypersurfaces using Dolbeault cohomolcgy. It is shown that certain canonically defined forms on the spin bundle are preferred Dolbeault representatives for derivatives of the twister cohomology classes corresponding to the linearised field. In chapter four I generalise the results of chapter three to curved space using the Chern connection. In particular twistorial formulations of the constraint equations are given, and a formula for the evolution that satisfies the the vacuum evolution equations is given in terms of an "infinity" twistor and a "time" twister. This is then discussed. In chapter five I make some comments on the interpretation of a three form on the spin bundle discovered by B.A.J. Sparling as the gravitational hami1tonian. I then use this to show that one can give an interpretation of Penrose's quasi-local angular momentum twistor in terms of the canonical formalism.

My thesis is a collection of non-fiction and fictional narratives focused on domestic space and its impact on father-daughter relationships and vice versa. In all of the narratives the notion of a house under renovation serves as a vehicle for the figurative tension between members of the family and family space. The narratives offer no internal markers to indicate whether they are fiction or non-fiction, which demonstrates my conviction that only factors external to the text---relation to fact or to imagination---can determine a narrative's status as fiction or non-fiction. / The required afterword to my narratives discusses the theoretical problem of the distinction between fiction and non-fiction as well as the living nature of material culture and space as reflections and mediators of father-daughter relationships.

Thesis (Ph.D.)--University of Tulsa, 1990. / Bibliography: leaves 223-229.

Thesis -- Departmental honors in English. / Short stories and an essay: The notion of home : an exploration of domestic setting in contemporary fiction. Bibliography: ℓ. 176-177.

Thesis (Ph. D.)--Oregon State University, 2000. / Typescript (photocopy). Includes bibliographical references (leaves 74-76). Also available on the World Wide Web.