11,330 research outputs found
The complex sine-Gordon model on a half line
No full textIn this thesis, we study the complex sine-Gordon model on a half line. The model in the bulk is an integrable (l+1) dimensional field theory which is U(1) gauge invariant and comprises a generalisation of the sine-Gordon theory. It accepts soliton and breather solutions. By introducing suitably selected boundary conditions we may consider the model on a half line. Through such conditions the model can be shown to remain integrable and various aspects of the boundary theory can be examined. The first chapter serves as a brief introduction to some basic concepts of integrability and soliton solutions. As an example of an integrable system with soliton solutions, the sine-Gordon model is presented both in the bulk and on a half line. These results will serve as a useful guide for the model at hand. The introduction finishes with a brief overview of the two methods that will be used on the fourth chapter in order to obtain the quantum spectrum of the boundary complex sine-Gordon model. In the second chapter the model is properly introduced along with a brief literature review. Different realisations of the model and their connexions are discussed. The vacuum of the theory is investigated. Soliton solutions are given and a discussion on the existence of breathers follows. Finally the collapse of breather solutions to single solitons is demonstrated and the chapter concludes with a different approach to the breather problem. In the third chapter, we construct the lowest conserved currents and through them we find suitable boundary conditions that allow for their conservation in the presence of a boundary. The boundary term is added to the Lagrangian and the vacuum is reexamined in the half line case. The reflection process of solitons from the boundary is studied and the time-delay is calculated. Finally we address the existence of boundary-bound states. In the fourth chapter we study the quantum complex sine-Gordon model. We begin with a brief overview of the theory in the bulk where the semi-classical spectrum and an exact S'-matrix are presented. Following that we use the stationary phase method to derive the semi-classical spectrum of boundary bound states. The bootstrap method is used as an alternative approach to obtain the same spectrum. The results are discussed and compared. The final chapter consists of a general discussion on open questions and problems of the model, and some proposals for further research
On the integrability of the sine-Gordon system
No full textThis thesis investigates the integrability of the sine-Gordon system of nonlinear partial differential equations when the dependent variables are subject to some very particular boundary conditions. In chapter 1 the sine-Gordon system is introduced and, with N ϵ Z, P, Q ϵ R, the sets of initial-boundary value problems A(_N) and B(_P,Q) are defined. In the set A(_N) at the spatial variable x is unbounded and the boundary conditions are fixed by initially choosing the topological charge N. This set of problems is the one usually associated with the sine-Gordon system. In the set B(_P,Q) the spatial coordinate is constrained to the semi-line (-oo,0) and there exists two boundary parameters P,Q ϵ R to be chosen a priori. It is the study of this second set of initial-boundary value problems for arbitrary P, Q which forms all the original work of this dissertation. The study presented here is primarily concerned with the development of three separate inverse scattering methods for solving these sets of initial-boundary value problems. The first of these is developed in chapter 3 and is applicable to a subset of the problems in A(_N). The method is the one usually associated with the sine-Gordon system and studies the asymptotics of the initial data as x → ±oo. It is included in this thesis for completeness and as background for the original material which follows. Next, in chapters 4 and 5, the inverse scattering methods appropriate to initial-boundary value problems in subsets of B(_P,O) and B(_P,Q#O) are constructed. In these cases it is important to realise that it is only possible to study the asymptotics of the initial data as x → -oo. Once these three methods have been formulated they are used to find soliton solutions and infinite sets of integrals of motion for these boundary value problems. When a boundary is present at x = 0 the interaction of the solitons with this boundary is studied. These topics are addressed in chapter 6. Finally in chapter 7 the question of the integrability of both sets of problems is addressed. By interpreting the various inverse scattering methods in terms of canonical coordinate transformations of phase space it is seen that the existence of such methods can be viewed as a constructive proof of the integrability of these boundary value problems
Left to right, Mr. Hulbert Smith, Scott McDonald, Gordon Smith, Mrs. W. D. Smith who looks on as Mr. Smith does the cooking honors, and Mr. Jack Llewellyn
No full text(Left to right) Mr. Hulbert Smith, Scott McDonald, Gordon Smith, Mrs. W. D. Smith who looks on as Mr. Smith does the cooking honors, and Mr. Jack Llewellyn. All the men and women are sitting around a campfire engaging in conversation as the dog sits in the middle.https://mavmatrix.uta.edu/specialcollections_startelegram1940s/4236/thumbnail.jp
Complex sine-Gordon theory: solitons, defects and boundaries
No full textThis thesis presents research into the properties and features of the complex sine- Gordon theory. The CSG theory is a dimensional integrable held theory that admits soliton solutions which carry a Noether charge due to the U(I) invariance of the theory. Integrable CSG defects and boundaries are constructed and interactions between solitons, defects and boundaries are analysed at the classical and quantum level. The introduction of defects into the theory is facilitated by a new Backlund transformation involving two parameters. Defect conditions, constructed so they maintain the integrability of the theory and found to be exactly the BT, are used to sew two CSG theories together. How solitons interact with the defect is investigated, in particular whether as in the SG theory solitons can be absorbed and emitted by the defect. The classical time-delay and phase-shift are calculated for soliton-defect and particle-defect scattering. Using the CSG defect to dress the Dirichlet boundary a new CSG boundary theory is produced. Its integrability is checked by the explicit construction of conserved charges. The various interactions between solitons and the boundary are analysed, compared and contrasted with the defect theory. Finally aspects of the quantum CSG boundary theory are examined, culminating in a conjecture for the quantum reflection matrix for a Q = -1-1 soliton reflecting from an unexcited boundary. Reflection and boundary bootstrap procedures are used to generate the general reflection matrix for any charged soliton reflecting from any excited boundar
Cartesian closed categories of separable Scott domains
No full textWe classify all sub-cartesian closed categories of the category of separable Scott domains. The classification employs a notion of coherence degree determined by the possible inconsistency patterns of sets of finite elements of a domain. Using the classification, we determine all sub-cartesian closed categories of the category of separable Scott domains that contain a universal object. The separable Scott domain models of the λβ-calculus are then classified up to a retraction by their coherence degrees
Sherri Scott Interview
No full textSherri Scott (Class of 1999) was interviewed by Valeria Reynosa via the Zoom internet-based video conferencing software on March 19, 2021. Ms. Scott was born into a military family and lived in South Carolina, Spain, and California before her family relocated to Abilene, Texas when she was eleven years old. During her interview, she discusses her experiences growing up on various military bases and in Abilene. She talks about her love for literature, particularly the Texas author Larry McMurtry, and how the heroine of his book The Last Picture Show inspired her to attend SMU. While at SMU, she majored in Psychology with a minor in Journalism, and pledged to the Alpha Kappa Alpha sorority. She also wrote for the Daily Campus and the Rotunda yearbook. She discusses the impact the AKA sorority had on her time at SMU, with particular regard to their community service events and outreach to the Black community in Dallas. Ms. Scott also talks about the mentors she had while at SMU and the friendships she formed, which have lasted well beyond her graduation date. After graduating in 1999, Ms. Scott worked as an associate editor at D Magazine, a production assistant in Wilmington, North Carolina, and editor-in-chief for a QSR magazine. She then began a career in public relations and marketing. At the time of the interview, she worked as as the Senior Vice President of Marketing for Public Broadcast Atlanta
Supp_Table_1_Biobanks_and_the_Moral_Concerns_of_Donors_QHR – Supplemental material for Biobanks and the Moral Concerns of Donors: A Democratic Deliberation
No full textSupplemental material, Supp_Table_1_Biobanks_and_the_Moral_Concerns_of_Donors_QHR for Biobanks and the Moral Concerns of Donors: A Democratic Deliberation by Raymond G. De Vries, Kerry A. Ryan, Linda Gordon, Chris D. Krenz, Tom Tomlinson, Scott Jewell and Scott Y. H. Kim in Qualitative Health Research</p
Citizen participation in news
No full textThe process of producing news has changed significantly due to the advent of the Web, which has enabled the increasing involvement of citizens in news production. This trend has been given many names, including participatory journalism, produsage, and crowd-sourced journalism, but these terms are ambiguous and have been applied inconsistently, making comparison of news systems difficult. In particular, it is problematic to distinguish the levels of citizen involvement, and therefore the extent to which news production has genuinely been opened up. In this paper we perform an analysis of 32 online news systems, comparing them in terms of how much power they give to citizens at each stage of the news production process. Our analysis reveals a diverse landscape of news systems and shows that they defy simplistic categorisation, but it also provides the means to compare different approaches in a systematic and meaningful way. We combine this with four case studies of individual stories to explore the ways that news stories can move and evolve across this landscape. Our conclusions are that online news systems are complex and interdependent, and that most do not involve citizens to the extent that the terms used to describe them imply
Belonging and not belonging : understanding India in novels by Paul Scott, Ruth Prawer Jhabvala and V.S. Naipaul.
No full textPhDThis thesis is essentially about the "how" and "why" of the Indian
experience as documented in novels by Paul Scott, Ruth Prawer Jhabvala
and V S Naipaul. The study points to the difficulty of arriving at any
conclusive definition of the country and its people. I show that
differences in attitudes, responses or behaviour are both overt and
subtle, and depend upon whether the writer or the character identifies
with the situation or community with which he or she interacts. It is
the individual's sense of belonging or not belonging to his or her own
group - be this along racial, cultural or gender lines - that accounts
for the differing perspectives evident in these novels. The points-of-
view of the outsider and the insider can therefore be seen as
mutual comments upon the other.
Since the struggle between belonging and not belonging becomes acute
when the old meets the new, focus is centred on communities
experiencing change. These include the British in India, West-Indian
Indians and westernised Indians. Despite their differences, all three
communities share similar reasons for either an acceptance or
rejection of the 'Other'. The thesis argues that the need for
emotional stability compels allegiance to the traditional group, while
the desire for individuality encourages surrender to the new. The
former nurtures a sense of belonging while, it is argued, that the
latter is perceived as the hallmark of those who do not belong.
Tensions arise when both these needs demand to be met. What I show to
be ironic in this struggle between belonging and not belonging is that
those things which individuals overtly reject are often unexpressed
parts of their personal pysche. The barrier between "them" and "us" is
therefore very fragile
Much Ado About Nothing? The Surprising Persistence of Nascent Entrepreneurs Through Macroeconomic Crisis
No full textArticle first published online: 26 FEB 2015. Journal Edited By: D. Ray Bagby, Baylor UniversityWe hypothesize that a major macroeconomic crisis triggers four alternative responses among nascent entrepreneurs: disengagement, delay, compensation, and adaptation. We also suggest that commitment and ambition (or “high potential”) moderate these responses. Our most important finding is the relative absence of behavioral crisis responses. However, crises may make high-tech founders become more likely to disengage, whereas the opposite holds for founders far into the process. Our study sheds light on the mechanisms behind aggregate effects of crises on the number and type of start-ups in an economy, and can guide future research on the effect of crises on nascent entrepreneurship.Per Davidsson, Scott R. Gordo
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