Dissertations / Theses: 'Strong brands'

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Knutsson, Andreas. "Strong Brands: Some Fundamentals and Benefits." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-32945.

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Das, Samar Kumar 1956. "A consumer-based theory of strong brands and its implications for brand equity and brand management." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288858.

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The power of brands like Coke, Levi's and Nike defies conventional understanding. How do such strong brands get created? What are the sources of their phenomenal strength? The traditional thinking reflected in the brand literature traces the sources of brand strength to the consumer's cognitive knowledge of brand's functional and image attributes, and other associations linked to the brand. I draw upon past research in marketing and social psychology to propose a user-centered view of brand strength. I suggest that loyal consumers actively create 'brandspaces' based on personal, social and cultural factors. These brand knowledge structures may be more insular since they are self generated and anchored in the personal and social self of the user. In Essay 1 of this dissertation, I take the user-centered approach to propose a method for mapping and measuring consumer-based brand equity. I developed a structural model for the sneakers product category with five consumer-based sources of brand equity ('functional attributes','brand image','appeal', 'self-brand relationship', and 'perceived popularity') as independent variables, and study their impact on a four indicator measure of brand equity. In Essay 2, I investigate the role of self-brand relationship schema in promoting insularity of strong brands. I hypothesize that strong brand users, who have high self-brand relationship, suppress or discount negative brand information, as compared to strong users who have low self-brand relationship. Experimental results confirm this central hypothesis. This study clearly shows the centrality of self-brand relationship in promoting brand insularity and brand strength.

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Stenman, Erika. "Strong Employer Brands and Employee Advocacy in Social Media : exploring the Employee Perspective." Thesis, Högskolan Kristianstad, Fakulteten för ekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-19682.

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Employer Branding activities in the competitive labour market are becoming increasingly interactive rather than being a top-down exercise. Limited resources together with new technology is playing a role in this development. Little, but some research exists on Employee Advocacy or the voluntary promotion and defence of a brand by its employees. While some researchers suggest that strong Employer Brands fosters Employee Advocacy, there seem to be little empirical support or comprehensive models incorporating the supportive factors. Earlier studies have been primarily quantitative in nature, focusing on the corporate perspective. This research adds a qualitative angle with focus on the Employee Perspective. The purpose with this thesis is to explore how employees in companies with strong Employer Brands practice Employee Advocacy in a Social Media context, Because of the subjectivist and abductive approach, the method was qualitative in form of interviews with employees of different companies in the service sector as primary data together with secondary data. The findings indicate that Employee Advocacy, although largely driven by employee commitment, in practice seem to be a rather temporary phenomenon. The dominating intrinsic motives for Employee Advocacy does not seem to translate in a Social Media Context, where nature of expression ultimately seem to depend more on external or situational factors. The limitations of this study are the small number of respondents made up of a convenience sample. The narrow theoretical base also limits the study to explore and broaden a phenomenon rather than developing an entirely new concept. The conceptual model could act as a basis for other studies with a combined qualitative/quantitative approach or as a basis for discussion in companies formulating their Employer Branding or Social Media strategies. The original value of the conducted study is a comprehensive model of shapers and some new empirical insights regarding complexities of the Employee Advocacy phenomenon.

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Kindblom, Louise. "UNGDOMAR OCH DERAS UPPFATTNINGAR AV MODEVARUMÄRKEN : En studie av varumärkena Gucci, H&M och Canada Goose bland gymnasieelever i Stockholm." Thesis, Uppsala University, Media and Communication, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9157.

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ABSTRACT

Title: Teenagers and their perception of fashion brands (Ungdomar och deras uppfattningar om modevarumärken)

Number of pages: 42

Author: Louise Kindblom

Tutor: Göran Svensson

Course: Media and communication studies C

Period: Autumn term 2007

University: Division of Media and Communication, Department of Information Science, Uppsala university

Purpose/Aim: To achieve a deeper level of knowledge and a better understanding of high school teenager`s perception of the three fashion brands Gucci. H&M and Canada Goose and too distinguish potential gender related differences in their perceptions.

Material/Method: A questionnaire about fashion brands delivered to three schools in the Stockholm area.

Main results: Teenagers perceptions of the three fashion brands Gucci, H&M and Canada Goose are more different than similar. This differences in teenagers perceptions are discernible in a comparison between the most usual and unusual associations that are related to each of the brands. Gucci is associated with success, wealth, excitement and uniqueness. H&M is for example seen as earth-bound and has in a comparison with the other brands reached the highest level of positive associations. Canada Goose is seen as dishonest, and has the highest level of negative associations. Gucci and H&M are the strongest brands. They are strong regarding different aspects. Canada Goose is the least strong fashion mark. There are differences in perceptions of gender but they are quite seldom very big even if there are exceptions from this rule. The differences are more subtle.

Keywords: fashion brands, teenagers, perceptions, strong brands, associations, image, Kellers pyramid

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Söderberg, Evelina, and Amanda Wissinger. "How a fashion company can create higher brand equity - the importance of using social media." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25907.

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Purpose - With the social media's emergence in recent times, the main purpose of this study is to generate knowledge about social media communication’s impact on consumer-based brand equity, in terms of firm-created and user-generated social media communication. In order to make this possible, knowledge about customer’s perception about a specific brand is required. Furthermore, we are interested in explaining issues concerning how fashion companies can efficiently use social media, and the study’s intention is also to present recommendations of how companies can use social media as a marketing communication tool. Theory and hypothesis – This chapter deals with theory about consumer-based brand equity, where the different components of the model are presented. Also theory about social media, different social media applications and a social media strategy are described. Finally, firm- created and user-generated social media communications impact on brand equity are discussed, which leads to the study’s hypotheses. Methodology – The study has a triangulation consisting of both a qualitative and a quantitative part and has essentially a deductive approach. The study interviewed one expert in the fashion industry and one expert in the area of social media. An interview with the analysed company’s marketing manager was also made. The quantitative study was made on 624 respondents, which were all members of the company’s customer club. 97 of these 624 respondents were investigated in order to observe the impact of firm-created and user- generated social media communication on brand equity. Empirical findings and results – The findings in the study indicate that firm-created social media communication positively impact brand equity, while user-generated did not show to be significant. In this study it was shown that the majority of the respondents use social media, especially Facebook, and the content that most valuable was access to discounts and promotions as well as information about the brand and its products. Conclusion - Our study confirms the importance for companies to use social media as a marketing tool and it should be in all managers’ interest to make use of this channel. Also the importance of having high brand equity is highlighted and how the customer’s perceptions about a brand can be used as guidelines in order to increase brand equity.

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Ericsson, Maria, and Jacqueline Pettersson. "Lojala kunder och paraplyvarumärkesstrategier." Thesis, Linköping University, Department of Management and Economics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2516.

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Den övergripande problematiken vi identifierat är relationen mellan starka varumärkenoch kundlojalitet i företag med flera olika produktvarumärken. Syftet med denna uppsats är att förstå om och hur företag med paraplyvarumärkesstrategier kan skapa och bibehålla lojala kunder. Vi vill överföra det övergripande teoretiska resonemanget inom varumärkesstrategi och inom lojalitetsstrategi på företag med paraplyvarumärkesstrategier.

Varumärket Axfood är ett exempel på ett företag som har flera olika produktvarumärken (Hemköp, Willy:s, Willy:s hemma med flera). Vi har vid genomförandet av studien valt att använda oss av Axfood som studieobjekt. Vi har intervjuat medarbetare och kunder till Axfood för att samla in relevant data.

Vi anser att det går att skapa lojala kunder för företag med paraplyvarumärkesstrategier. Det som avgör om det är möjligt är om de olika produktvarumärkena står för samma grundläggande kärnvärden. Produkterna kan skilja sig åt vad gäller typ av produkt eller karaktär, men vissa grundläggande variabler måste vara lika för att det ska vara möjligt att skapa lojalitet.

The comprehensive problems we acknowledged are the relationship between strong brands and customer loyalty in corporations with umbrella brand strategies. The purpose of this thesis is to understand if and how corporations with umbrella brand strategies can create and retain loyal customers. Our intention is to apply the theoretical framework of brand strategy and loyalty strategies on corporations with umbrella brand.

Axfood is one example of a corporation which hold a number of product brands (Hemköp, Willy:s, Willy:s hemma et cetera). In this study we have chosen to use Axfood as an object of study and we have interviewed employees and customers to collect relevant data.

Our conclusions are that it is possible to create loyal customers in corporations with umbrella brands. The crucial aspects are that the product brands support the same fundamental values. The products can differ considering type of product or characteristics but some fundamental values has to be equal to make it possible to create loyal customers.

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Wiseman, Toby Augustus Julius. "Strong gravity on branes." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620574.

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Stiffler, Kory M. "A walk through superstring theory with an application to Yang-Mills theory: k-strings and D-branes as gauge/gravity dual objects." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/744.

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Superstring theory is one current, promising attempt at unifying gravity with the other three known forces: the electromagnetic force, and the weak and strong nuclear forces. Though this is still a work in progress, much effort has been put forth toward this goal. A set of specific tools which are used are gauge/gravity dualities. This thesis consists of a specific implementation of gauge/gravity dualities to describe k-strings of strongly coupled gauge theories as objects dual to Dpbranes embedded in confining supergravity backgrounds from low energy superstring field theory. Along with superstring theory, k-strings are also commonly investigated with lattice gauge theory and Hamiltonian methods. A k$string is a colorless combination of quark-anti-quark source pairs, between which a color flux tube develops. The two most notable terms of the k-string energy are, for large quark anti-quark separation L, the tension term, proportional to L, and the Coulombic 1/L correction, known as the Luscher term. This thesis provides an overview of superstring theories and how gauge/gravity dualities emerge from them. It shows in detail how these dualities can be used for the specific problem of calculating the k-string energy in 2+1 and 3+1 space-time dimensions as the energy of Dp-branes in the dual gravitational theory. A detailed review of k-string tension calculations is given where good agreement is found with lattice gauge theory and Hamiltonian methods. In reviewing the k-string tension, we also touch on how different representations of k-strings can be described with Dp-branes through gauge/gravity dualities. The main result of this thesis is how the Luscher term is found to emerge from the energy calculation of Dp-branes. In 2+1 space-time dimensions, we have Luscher term data to compare with from lattice gauge theory, where we find good agreement.

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JIN, YOUQI, and XIAOCHEN XU. "Developing a strong brand." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15581.

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Wulff, Linus. "Strings, boundary fermions and coincident D-branes." Doctoral thesis, Stockholm : Department of Physics, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6576.

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Brandt, Heidi Kay. "Stroke education packet: the inpatient environment." Thesis, Montana State University, 2010. http://etd.lib.montana.edu/etd/2010/brandt/BrandtH0810.pdf.

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Stroke is a disease process that affects more than 700,000 people per year. Many of those individuals enter the acute care setting with questions and concerns regarding the causes of stroke and implications of a stroke diagnosis. To answer those questions, national guidelines regarding stroke education have been created to help nurses present information to stroke patients and their families. In one acute care facility, there was a lack of an educational packet for nurses to use to teach this vital information. The purpose of this clinical project was to create an evidence-based stroke education packet for nurses at this facility to use to teach stroke patients and their families. Evidence was compiled from the literature, evidence-based guidelines, and multiple stroke-education packets, brochures, and patient education materials used by nurses at other health care facilities. The packet was created and presented to the institution as a usable tool to facilitate the delivery and documentation of stroke education to patients and their families.

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Henriksson, Linnea, and Eijk Sabina van. "Managing brand associations : The key to strong and successful brand equity." Thesis, Södertörns högskola, Institutionen för ekonomi och företagande, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-16944.

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Denna uppsats behandlar varumärkesassociationer samt dess påverkan på varumärkeskapital. Uppsatsen är genomförd som en fallstudie och undersöker hur det svenska telekommunikationsföretaget Tre tolkar konsumenters associationer till varumärket Tre. Detta jämförs sedan med de varumärkesassociationer som föreligger kring Tres varumärke på marknaden. Varumärkesassociationer formas primärt hos konsumenter och är således inte enbart en process som företag styr. Detta innebär dock inte att associationerna är opåverkbara från företagets sida. En central faktor som påverkar skapandet av varumärkesassociationer har i denna uppsats påvisats vara konsumenters kontakt med företaget, där framförallt den första kontakten tenderar att forma associationerna. Konsumenter behöver inte ha en personlig relation till varumärket för att forma sina associationer då word-of-mouth har visat sig ha en stor påverkan på skapandet och spridandet av varumärkesassociationer. Företags varumärkeskapital gynnas av många samt positivt betingade varumärkesassociationer. För det i uppsatsen studerade företaget tenderar dock en majoritet av de kartlagda associationerna att vara negativa, vilket i sin tur har tenderat att skada det totala varumärkeskapitalet. En annan intressant aspekt av detta är att många bärare av dessa negativa associationer inte själva har en personlig erfarenhet av företaget. Detta understryker kraften av word-of-mouth samtidigt som det betonar vikten av att som företag ha en välarbetad kundstrategi då den har en direkt påverkan på företagets varumärkeskapital. I många framträdande teorier beskrivs det att förmedling av varumärkesassociationer gynnas av att framhäva emotionella faktorer, då dessa sägs ha en djupare påverkan på människors värderingar än vad funktionella faktorer har. Vad uppsatsens empiri dock har kunnat påvisa är att detta är svårt i en teknikorienterad bransch då konsumenter värderar funktionella faktorer högre än emotionella. De funktionella faktorerna tenderar även att ha en stor betydelse för varumärkesassociationer. Uppsatsen presenterar avslutningsvis en nyskapad figur vilken sammanfattar strategiskt betydelsefulla områden som Tre fördelaktigt kan använda sig av för att skapa ett starkt varumärkeskapital.
In this paper brand associations are examined, along with its impact on brand equity. The thesis is completed as a case study and examines what the Swedish telecommunication company Tre believes are the markets associations of their brand. This is later compared with the consumers actual associations with the brand Tre. Brand associations are primarily formed by consumers and are thus not only a process of corporate governance. This does not mean that the associations are impossible to influence by the company. The result of this study has shown that a key factor influencing the creation of brand associations is consumers’ contact with the company, where especially the first contact tends to form associations. Consumers do not need to have a personal relationship with the brand to form their associations as word-of-mouth has been shown to have a major impact on the creation and distribution of brand associations. Brand equity grows stronger by many and positively charged brand associations. However, for the company Tre, the majority of the identified associations are seen as negative, which in turn tend to harm the overall brand equity. Another interesting aspect of this is that many carriers of these negative associations do not have a personal experience with the company. This underlines the power of word-of-mouth, while emphasizing the importance to have a well-made customer strategy as it has a direct impact on the company's brand equity. Mediation of brand associations is in many prominent theories described favored by highlighting emotional factors as they are said to have a deeper impact on human values than functional factors. This has, by this study´s empirical thesis, shown to be difficult in a technology-oriented industry where consumers value the functional factors higher than the emotional factors. The functional factors also tend to have a important influence on brand associations. The conclusion of this paper presents a new figure that summarizes strategically important areas for the company Tre to create stronger brand equity.

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Sigalov, Ilya. "D-branes and string field theory." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/39560.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.
Includes bibliographical references (p. 115-127).
In this thesis we study the D-brane physics in the context of Witten's cubic string field theory. We compute first few terms the low energy effective action for the non-abelian gauge field A, from Witten's action. We show that after the appropriate field redefinition which relates the string field theory variables to the worldsheet variables one obtains the correct Born-Infeld terms. We then compute the rolling tachyon solution in the context of string field theory. We show that after the appropriate field redefinition we obtain the rolling tachyon solution of Sen.
by Ilya Sigalov.
Ph.D.

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Ng, Selena Kim Leng. "Aspects of branes in string theory." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620652.

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Bevilaqua, Leandro Ibiapina. "\"Branas em supergravidade\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29032007-211600/.

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Este trabalho tem o objetivo de rever a obtenção das soluções do tipo brana em supergravidade e contém uma dedução detalhada das soluções extrema e negra. A fim de motivar algumas escolhas feitas ao longo do cálculo, o trabalho inclui uma breve revisão dos conceitos advindos da teoria de cordas e supersimetria. Esta revisão nos permitirá ainda relacionar as soluções da supergravidade com as branas da teoria de cordas e tecer considerações sobre o papel desta relação na dualidade entre teoria de calibre e gravitação.
This work intends to review the brane solutions of supergravity and contains a datailed deduction of the extremal and black solutions. In order to provide some motivations to the choices through the calculation, this work includes a brief review of some concepts from string theory and supersymmetry. This review will enable us to relate the supergravity solutions to string theory\'s branes and to make considerations about the role of this relationship in the duality between gauge and gravity theories.

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Li, Yunyu, and Chang Liu. "How Chinese SME perceive the strong brand as a crucial factor for establishing competitiveness?" Thesis, Linnéuniversitetet, Institutionen för marknadsföring (MF), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-56332.

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The globalization become a current tendency, and China as one of the biggest parts in the international market, plays the important role. Considering the SMEs in China occupy the main amount, Chinese SMEs are the key factors in Chinese economy. At the same time, they are also faced with fierce competition from global company that compared with other developed countries’ SMEs, Chinese SMEs are not competitive enough. One of the reasons is that their brands are lack of competitiveness. It is known to all, brand is a key strategic asset to long-term performance and it should be managed. Therefore this study is focused on how Chinese SMEs perceive brand as crucial factor for establishing competitiveness. This study is based on qualitative research, and case study research design is chosen. The semi-structured interview is conducted in the Chinese SME called CSC, and two managers and three employees were interviewed. In conclusion, it can be found that the CSC pays attention to the brand, but their brand still need to be improved to be more powerful, unique and positiveness then to reach the loyalty of consumers, and the media channels should be paid more attention

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O'Driscoll, D. C. "D-branes and orientifolds in string theory." Thesis, Swansea University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638350.

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We examine the interplay of supersymmetry and compactification on D-branes and orientifold planes using the framework of superstring theory. We explore issues pertinent to geometrical descriptions of these theories and dualities among them.

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da, Costa M. S. "Branes and black holes in string theory." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598237.

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The goal of this thesis is to address several issues in gravitational physics, in particular black hole physics, within a quantum mechanical framework. Of course this requires the existence of such a quantum mechanical theory of gravity. Superstring theory is a consistent perturbative theory of gravity. However, many aspects of the theory turn out to be non-perturbative and in this sense the theory is still under construction. The theory of strings contains a large variety of p-dimensional spatially extended objects, now called p-branes. These p-branes are dynamical objects embedded in space-time: they interact between each other, intersect each other and bound themselves together. In this thesis I shall study some of these p-brane configurations. I shall start by using supergravity which is a large distance (low energy) approximation to string theory, to construct many new p-brane configurations. The emphasis will be on the technics to construct the supergravity solutions describing these configurations and on the symmetries of the underlying theory that render their existence. I shall not attempt to give a complete classification of the p-brane configurations folklore nor shall I address issues related to the global structure of the corresponding gravitational geometry. In turn, the focus will be on the microscopic and quantum mechanical description of some of these p-brane configurations, namely the D-brane bound states. In particular, I shall study in detail a D-5 brane configuration with a constant magnetic field on its worldvolume. The gravitational counterpart is a five-dimensional black hole. The quantum mechanical description of this system will allow the calculation of the Bekenstein-Hawking entropy from counting microscopic states of the D-brane system. The scattering of a scalar particle off the black hole (and therefore Hawking radiation) are also studied. I end by making a proposal for an effective string description of black hole dynamics. In the process I shall use results in perturbative string theory, gauge theory and gravitational theory. In this sense, this thesis is rather interdisciplinary which is a remarkable characteristic acquired by superstring theory.

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Gutperle, Michael. "Dirichlet branes, Dirichlet instantons and string duality." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627362.

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Stefański, Bogdan. "String theory, dirichlet branes and K-theory." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621023.

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Monahan, Lisa. "Hate is a Strong Word: The Influence of Hate-Acknowledging Advertising on Brand Outcomes." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6908.

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Given a lack of tactics for addressing brand hate, most managers tend to ignore brand haters, and instead dedicate their resources towards consumers who like or love their brand. Similarly, relative to the volume of research on positive brand emotions, the academic literature exploring negative brand emotions is limited. Moreover, research indicates that compared to positive brand information, negative brand information is more diagnostic, and ultimately more damaging. In contrast to such findings and practices, this dissertation proposes a strategy whereby using advertising to openly acknowledge that a brand is hated (i.e. hate-acknowledging advertising) can be advantageous for corporate polarizing brands. The findings suggest that, compared to a traditional ad (i.e., an ad which only focuses on positive brand attributes or information), a hate-acknowledging produces higher levels of brand trust through the mediating influence of ad credibility. This research also demonstrates that hate-acknowledging advertising (vs. traditional advertising) has a stronger and more favorable influence on consumer intentions to engage in positive word of mouth, and that consumer brand emotions moderate this effect. Specifically, the favorable influence of hate-acknowledging on positive word of mouth intensifies with higher levels of consumer love towards a polarizing brand.

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Witkowski, Lukas Thomas. "Sequestering of Kähler moduli in type IIB string theory." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6f5c8a99-26ca-401b-ad42-7bd3bf873f80.

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In this thesis we employ string perturbation theory in toroidal orbifold models to study aspects of supersymmetry breaking in type IIB string theory. First, we determine the dependence of physical Yukawa couplings on blow-up moduli in models with D3-branes at orbifold singularities. Blow-up moduli are scalar fields describing the size of small blow-up cycles in the compactification geometry. In models implementing moduli stabilisation these fields can acquire F-terms and break supersymmetry. We examine the moduli-dependence of physical Yukawa couplings at string tree-level by computing disk correlation functions involving a Yukawa interaction of visible sector fields and an arbitrary number of blow-up moduli. We perform the calculation for one blow-up insertion explicitly and find that the correlation function vanishes if the blow-up modulus is associated with a small cycle distant to the visible sector. For more than one blow-up insertion we show that all such correlation functions are exponentially suppressed by the compactification volume. We explain how these results are relevant to suppressing soft terms to scales parametrically below the gravitino mass. Further, we determine corrections to holomorphic Yukawa couplings on D3-branes at an orbifold singularity due to non-perturbative effects such as gaugino condensation on a stack of D7-branes. This can be done by calculating a one-loop threshold correction to the gauge coupling on the D7-branes. We show that, if present, the new contributions to Yukawa couplings are not aligned with the tree-level couplings. As the new Yukawa couplings contribute to soft A-terms they are sources of flavour-changing neutral currents. Last we discuss an effect unrelated to supersymmetry breaking. We show that orbifold models with D3-branes at orbifold singularities can exhibit kinetic mixing of different massless Abelian factors. For this to be possible, the relevant U(1) factors have to be associated with more than one orbifold singularity.

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Görlich, Lars. "N = 1 and non-supersymmetric open string theories in six and four space-time dimensions." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2003. http://dx.doi.org/10.18452/14978.

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Die vorliegende Arbeit beinhaltet ein einführendes Kapitel über Orbifold-Konstruktionen in dem neben rudimentären Grundlagen bereits speziellere Themen wie Diskrete Torsion und asymmetrische Orbifold-Gruppen behandelt werden. Als Beispiele für Orbifolde werden Kompaktifizierungen auf Tori sowie das asymmetrische T^4/Z(3)^L x Z(3)^R Orbifold behandelt. Danach wird eine allgemein gehaltene Einführung in Orientifolde gegeben, einschließlich des offenen String Sektors samt Chan-Paton Freiheitsgraden. Die darauf folgenden Kapitel 4-7 behandeln von mir durchgeführte Forschungsarbeiten. Kapitel 4 beschäftigt sich mit der Quantisierung des offenen Strings mit linearen Randbedingungen, wie sie bei Strings in elektro-magnetischen Feldern auftreten. Weiterhin wird die Quantisierung der Null- und Impuls-Moden des offenen Strings in Torus-Kompaktifizierungen durchgeführt. Außerdem wird für den Fall allgemeiner konstanter Hintergrund Neveu-Schwarz U(1)-Hintergrundfelder der Kommutator der Stringkoordinaten berechnet. Dieser stützt bisherige Resultate zur Nicht-Kommutativität von offenen Stringtheorien in Neveu-Schwarz Hintergründen. Kapitel 5 gibt, zusammen mit einigen neuen Erkenntnissen, Resultate von [1] über asymmetrische Orientifolde, insbesondere deren D-Branen Inhalt wieder. Kapitel 6 faßt die Veröffentlichung [2] zusammen, in der untersucht wurde, inwieweit sich phänomenolgisch interessante Modelle in Orientifolden von Torus-Kompaktifizierungen finden lassen. Insbesondere tragen die D9-Branen magnetische Flüsse, womit chirale Fermionen im Spektrum auftreten. Die Rechnungen werden größtenteils im gleichwertigen, T-dualen Bild ausgeführt. In diesem ist die Anzahl der chiralen Fermionen durch die topologische Schnittzahl der D-Branen gegeben. Existieren auf Torus-Kompaktifizierungen entweder nur nicht-chirale oder nicht-supersymmetrische Modelle, so lassen sich auf gewissen Orbifolden beide Eigenschaften miteinander vereinbaren. Kapitel 7 behandelt das "sigma Omega"-Orientifold auf einem T^6/Z(4) Orbifold. Als besonders interessantes Beispiel wird ein supersymmetrisches U(4) x U(2)^3_L x U(2)^3_R Modell vorgestellt, daß durch Einschalten geeigneter Hintergrundfelder in der effektiven Niederenergie-Wirkung auf ein Modell gebrochen wird, daß dem MSSM (minimalem supersymmetrischen Standard Modell) sehr ähnlich ist. Dieses Kapitel basiert auf unserer Publikation [3]. Ferner ist der Arbeit ein Anhang beigefügt, der einige der verwendeten Formeln sowie Beweise zu zwei Sätzen enthält, die im Text verwendet wurden.
This thesis contains an introductory chapter on orbifolds. Besides rudimentary basics we discuss more advanced topics like discrete torsion and asymmetric orbifold groups. As examples we investigate torus compactifications and an asymmetric T^4/Z(3)^L x Z(3)^R orbifold. The following chapter explains the foundations of orientifolds, including open strings with Chan-Paton degrees of freedom. Chapters 4-7 present own research. In chapter 4 we quantize open strings with linear boundary conditions, as they show up in electro-magnetic fields. We quantize the zero- and momentum-modes for toroidal compactifications, too. As an application we calculate the commutator of the coordinate fields in the case of general constant Neveu-Schwarz U(1)-field strengths. Thereby we confirm previous results on non-commutativity of open string theories in Neveu-Schwarz backgrounds. Chapter 5 reviews the results of a former publication [1] on asymmetric orientifolds, supplemented by some recent insights in connection with the preceeding chapter. Chapter 6 is a summary of [2]. In this publication we investigated to what extend one can build phenomenologically interesting models from toroidal orientifolds. By turning on magnetic fluxes on D9-branes we induce chiral fermions. Most calculations are performed in an (equivalent) T-dual picture. Here the number of chiral fermions is given by the topological intersection number of D-branes. In orientifolds of toroidal compactifications one obtains either non-chiral or non-supersymmetric orientifold solutions. However both properties can be reconciled in orientifolds that are obtained from specific supersymmetric orbifold compactifications. In chapter 7 we present the "sigma Omega"-Orientifold on a T^6/Z(4) orbifold. As a very attractive example we investigate a supersymmetric U(4) x U(2)^3_L x U(2)^3_R model that is broken to an MSSM-like model by switching on suitable background fields in the low energy effective action. This chapter is based on our publication [3]. The thesis is supplemented by an appendix with formulas applied in the text, as well as proofs to two theorems that were used as well.

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Lambert, N. D., I. Sachs, and Andreas Cap@esi ac at. "String Loop Corrections to Stable Non--BPS Branes." J. High Energy Phys. 02 (2001), paper 018, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi954.ps.

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Karch, Andreas. "Field Theory Dynamics from branes in String Theory." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 1998. http://dx.doi.org/10.18452/14371.

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Nach jahrelanger Suche hat sich bis heute Stringtheorie als einziger Kandidat einer konsistenten Quantentheorie der Gravitation herauskristallisiert. Um aus der Stringtheorie präzise Vorhersagen für unsere Niederenergiewelt zu gewinnen, ist es notwendig, das Vakuumproblem zu lösen, das heißt einen Mechanismus zu finden, der aufzeigt, in welchem Stringvakuum wir leben und warum die Natur dieses ausgewählt hat. Die Beantwortung dieser Frage benötigt nicht-perturbative Informationen.Diese wurden erst in jüngster Zeit zugänglich. Eine besondere Rolle in dieser Entwicklung spielten die sogenannten D-branes. Sie stellen mögliche nicht-perturbative Beiträge zu Stringamplituden dar. Die Identifizierung, daß D-branes einfach Objekte sind, auf denen Strings enden können, ermöglicht sie zu handhaben und zu zeigen, daß ihre Dynamik im wesentlichen durch Eichtheorien erfaßt wird. D-branes erlaubten, zahlreiche Dualit\ätssymmetrien zu etablieren, deren Haupta ussage zu sein scheint, daß alle 5 Stringtheorien sowie 11d Supergravitation nur verschiedene perturbative Limites einer fundamentalen 11d Theorie sind, T-Theorie. In dieser Arbeit habe ich mich mit einigen Anwendungen dieser Ideen beschäftigt. Die Tatsache, daß D-branes durch Super Yang-Mills Theorien beschrieben werden, erlaubt uns einen Stringhintergrund derart zu präparieren, daß wir nahezu jede Eichtheorie als relevante Niederenergiebeschreibung erhalten können. Eine besonders verbreitete Variante dieser Idee sind die sogenannten ``Hanany Witten setups'', in denen dieser Stringhintergrund nur aus flachen branes im flachen Raum besteht. Mit Hilfe dieser Technik habe ich verschiedene Dualitätssymmetrien in Feldtheorien auf Stringdualitäten zurückgeführt. Ferner ist es möglich, mit Hilfe der branes die Existenz nicht trivialer Fixpunkt Theorien in sechs Dimensionen zu beweisen und einige ihrer Eigenschaften zu analysieren. Einige dieser Fixpunkte beschreiben Phasenübergänge zwischen verschiedenen brane Hintergründen. Unter anderem läßt es sich auf diese Weise zeigen, daß es in 4 Dimensionen Übergänge zwischen chiralen und nicht chiralen Vacua gibt. Ferner wurde gezeigt, daß alle anderen Zugänge zu dem Problem, Eichtheorien in Stringtheorie einzubetten, im wesentlichen äquivalent zum HW Ansatz sind, in dem Sinn, daß die entsprechenden Stringhintergründe dual zueinander sind. Dadurch können neue Aspekte der String T-Dualität verstanden werden, so wie z.B. T-Dualitäat für brane Segmente und gebogene branes.Außerdem erlaubt uns diese Verbindung, die Phasenübergänge, die wir im HW Bild entdeckt haben, tatsächlich als Übergänge zwischen topologisch verschiedenen Stringkompaktifizierungen zu verst ehen.
In this thesis I discussed several applications of the connection of non-perturbative string theory and SYM theory. In Chapter 1 I reviewed the physics of D-branes as one example of a non-perturbative effect in string theory. Their dynamics is dominated by gauge theory. This fact can be used to engineer certain string backgrounds which yield interacting SYM theories as their low-energy description. In Chapter 2 I then introduced one of the approaches in detail, the HW setup. I gave a summary of the identification of the classical gauge theory, showed how quantum effects manifest themselves in the brane picture and how to solve them. This way of embedding gauge theories into string theories has several interesting applications. These were the topic of Chapter 3. First I discussed dualities in field theory and showed how they arise as a natural consequence of string duality. As a second application I used branes to prove the existence of non-trivial fixed point theories in 6 dimensions and to study their properties. Some of these fixed points describe phase transitions between two different brane configurations. From a 4d point of view these 6d transitions can induce a chiral non-chiral transition. In Chapter 4 I discussed the relation of the HW setup with the other approaches of embedding gauge theory into string theory, especially the branes as probes approach. The different ways of embedding gauge theories in string theory are shown to be actually T-dual as string backgrounds. For one this allowed us to explore several new aspects of T-duality, like T-duality for bended branes and branes endin g on branes. In addition this relation can be used to show that the transitions found in the brane picture can as well be understood as transitions between topologically distinct compactifications of string theory. Some open problems and directions for further research were mentioned in Chapter 5.

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Feng, Bo 1971. "D-branes, gauge theory and string field theory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8491.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.
Includes bibliographical references (p. 245-262).
In this thesis, we present several works done in last three years. They include three directions in the string theory. In the first direction, we use the brane setup to find mirror pairs of SO(n) and Sp(k) gauge groups for N = 4 three-dimensional gauge field theories. To reach this result, we analyze carefully the s-configuration and predict a nontrivial string dynamics, i.e., the splitting of branes on the orientifold planes. In the second direction, we develop the "inverse algorithm" and use it to get nontrivial world volume theories of D-branes probing more exotic singularities. In this process, we find the "toric duality" which relates different phases of D-brane probe theories. We realize later that the toric duality is an example of the more powerful Seiberg-duality so these different phases are related by the Seiberg duality. In the third direction, by using numerical calculation we get a strong evidence to support the second conjecture of Sen's three conjectures. We show that if the identity field is BRST exact state around the tachyon vacuum, the open string spectrum will decouple from the physics and leave only the closed string spectrum.
by Bo Feng.
Ph.D.

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Prezas, Nikolas 1973. "Aspects of branes and orbifolds in string theory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8486.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.
Includes bibliographical references (p. 245-268).
The main theme of this thesis is branes and orbifolds in string theory, with some digression towards other directions in the final chapters. After reviewing background material on D-branes and orbifolds, along with some mathematical fundamentals, I describe the following results. First, a classification of discrete torsion for a large class of orbifolds and a technique for extracting the matter content of D-brane probe gauge theories on orbifolds with discrete torsion. Subsequently, I discuss an algorithm, called stepwise projection, that illuminates the structure of the so-called exceptional quivers, and hints towards the brane realization of the associated gauge theories. Next, I present the computation of the partition function of the coset conformal field theory describing the two-dimensional black hole. This computation confirms earlier results concerning the spectrum of the black hole and it enable us to identify the physical Hilbert space. This theory appears in the exact string theory description of configurations of Neveu-Schwarz 5-branes and in the conformal field theory description of certain orbifolds in singular limits; thus, it is only a mild digression from the main theme of the thesis. This is not so, however, for the last topic discussed here. We will change gears completely and discuss our extension of Witten's construction of boundary string field theory to the superstring. As in the bosonic case, the main tool we use is the Batalin-Vilkovisky formalism. Our construction proves a recent conjecture regarding the spacetime action of the supersymmetric theory and a related conjecture concerning quantum field theories on two-dimensional spaces with boundaries.
by Nikolas Prezas.
Ph.D.

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Sehmbi, Gurdeep Singh. "Branes and geometry in string and M-theory." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/3900/.

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This thesis is based on two papers by the author and consists of two parts. We review the recent developments in the theory of multiple M2-branes and 3-algebras leading to multiple D2-brane theories. The inclusion of flux terms for the supersymmetric BLG and ABJM theories of closed M2-branes is discussed and then generalised to open M2-branes. Here the boundary condition is derived and different BPS configurations are examined where we find a mass deformed Basu-Harvey equation for the M2-M5 system. The Lorentzian 3-algebra is then employed for obtaining a theory of D2-branes in a flux background, we then obtain the new fuzzy funnel solution of the system of D2-D4 branes in a flux. Matrix theories and their compactifications as well as noncommutative geometry and noncommutative gauge theories are reviewed with a discussion of their generalisations to three dimensions to be used to describe the M-theory three form potential. A new feature of string theory is then obtained called the quantum Nambu geometry (QNG). It is found by considering the action for D1-strings in a RR flux background and we demonstrate that there is a large flux double scaling limit where the action is dominated by a Chern-Simons-Myers coupling term. A classical solution to this is the quantised spacetime known as the quantum Nambu geometry. Various matrix models are obtained from this action, these are the large flux dominated terms of the full actions for the corresponding matrix models. The QNG gives rise to an expansion of D1-strings to D4-branes in the IIA theory, so we obtain an action for the large flux terms for this action which is verified by a dimensional reduction of the PST action describing M5-branes. We make a generalisation of the D4-brane action to describe M5-branes using a duality. We are describing the 3-form self-dual field strength of a non-abelian generalisation of the PST action.

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Pawelczyk, Jacek, Soo-Jong Rey, and jacek pawelczyk@physik uni-muenchen de. "Ramond--Ramond Flux Stabilization of D--Branes." ESI preprints, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi955.ps.

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Mattsson, Sofie, and Karin Gustafsson. "Personal Branding : How to develop and sustain a strong personal brand." Thesis, Jönköping University, JIBS, Business Administration, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-291.

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Branding of people is a relatively new concept within the branding area. This concept has grown rapidly and its importance is increasing. Our purpose of this thesis is to describe how a strong personal brand is developed and how it is sustained. We also want to highlight what factors that determine who will succeed to develop a strong personal brand and who will not and if the associations that other people have of you can be determined by the brand owner.

We have chosen to do a qualitative method by conducting interviews with five wellknown Swedish persons that we argue have or are beginning to develop strong personal brands within different areas.

The frame of reference consists of some concepts on traditional branding and models within the personal branding area. We found that the existing literature within personal branding was not sufficient to fulfil our purpose and therefore we have created a research model. The empirical findings are applied to the research model in the analysis.

We argue that the base to develop a strong personal brand is to truly know who you are and what you stand for. When you have a clear understanding about who you are, it is important to be consistent in the messages that you communicate in order to avoid confusion among other people. To have a strong personal brand, you also need to be well-known among more people than just your family and friends.

Personal branding is to a large extent about how other people perceive you and we argue that you can to some extent affect this image by being consistent and clear about who you are and what you stand for. People cannot see your thoughts, only your actions.

All people have a personal brand but we believe that the process to develop your personal brand depends on what goals you have with it and what you want to accomplish. All people do not gain anything by having a strong personal brand but we believe that all people can use some parts of the concept in order to know who you are and what you stand for.

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Yang, Benjamin H. (Benjamin Hoh). "A Study of the Relationship Between Motive and Structure in Brahms's op. 51 String Quartets." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc332309/.

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In 1873, Brahms completed the two op. 51 quartets. These were not the first string quartets Brahms composed, hut they were the first that Brahms allowed to be published. He found the string quartet difficult; as he confided to his friend Alwin Cranz, he sketched out twenty string quartets before producing a pair he thought worthy of publishing. Questions arise: what aspect of the string quartet gave Brahms so much trouble, and what in the op. 51 quartets gave him the inclination to publish them for the first time in his career? The op. 51 quartets are essential to understanding the evolution of Brahms's compositional technique. Brahms had difficulty limiting his massive harmony and polyphony to four solo strings. This difficulty was compounded by his insistence on deriving even the accompaniment from the opening main motivic material. This study investigates the manner in which Brahms distributes the main motivic material to all four voices in these quartets, while at the same time highlighting each voice effectively in the dialogue.

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Dawson, Peter Dale. "Effective actions and charges of D-branes in curved space-time." Title page, abstract and contents only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phd2727.pdf.

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Bibliography: leaves 181-190. This thesis firstly investigates K-invariant and supersymmetric actions of D-branes in curved space-time. Following this, research into charges of D-branes in a group manifold are studied. In particular, the charge groups are determined for the symmetry preserving (or untwisted) D-branes on a compact, simple, connected, simply connected group manifold. The purpose of this research is to determine these charge groups in order that they can be compared to the charge groups predicted by twisted K-theory for D-branes in a group manifold, thus providing a future important check to the theorem that D-brane charges are determined by twisted K-theory, one of the most important recent ideas in string theory.

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Vanichchapongjaroen, Pichet. "Branes and applications in string theory and M-theory." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10552/.

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This thesis discusses branes in string theory and M-theory. In chapter 1, we present background materials. In chapters 2 and 3, we discuss an application of a D3/D7 model in the framework of gauge/gravity duality, which uses the results of a gravity theory calculation to obtain informations about the corresponding gauge theory. Gauge/gravity duality is usually studied in a non-compact space. This thesis, however, focuses on the duality in a compact space. In chapter 2, we study a strongly coupled gauge theory in a compact space. We find that a homogeneous ground state is unstable at a sufficiently large isospin chemical potential. We then construct a new ground state which corresponds to a scalar meson condensate charged under a global SO(4) symmetry. In chapter 3, we discuss an on-going work. We study a strongly-coupled gauge theory living in a compact space with a generic value of quark mass at zero temperature in the presence of an external magnetic field. We are investigating the phase diagram of the external magnetic field and quark mass. In chapter 4 and 5, we move to M-theory. In chapter 4, we construct a complete non-linear theory of a supersymmetric single M5-brane with a 3+3 splitting. The M5-brane lives in a general background of M-theory. The idea of our construction is to get equations of motion that agree with that obtained from the superembedding approach. In chapter 5, we consider a model which attempts to describe a theory on multiple M5-branes. Using this model, we construct self-dual string solutions which describes M2/M5 branes intersection. These solutions are supported by magnetic monopoles. For self-dual strings with large number of M2 and M5-branes, we obtain the required radius-distance relationship and energy.

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Reimers, D. T. "Superalgebras and brane actions." University of Western Australia. School of Physics, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0045.

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The Noether charge algebra of brane actions is typically modified by a topological anomalous term. The underlying cohomology of this anomalous term is investigated, and it is shown that the anomalous term possesses a gauge freedom. The result is that the anomalous term generates a parameterized family of topological charge algebras. When fermionic charges are taken to be nonvanishing, the known algebras underlying extended superspace formulations of the action appear in these families. This phenomena is investigated for minimal p-branes, Dp-branes and (p, q)-strings. The algebras resulting from the D-brane actions are shown to allow the construction of extended superspace actions without worldvolume gauge fields. It is shown that the actions are !-symmetric, and that the symmetry is generated by a right action. The global and local symmetry transformations of the Born-Infeld gauge field are thus shown to be described geometrically by left/right actions of the underlying extended supertranslation group. An equivalence class construction is proposed for the description of compact fermionic dimensions. In this construction, open strings in extended superspace translate to closed strings in compact superspace, and fermionic topological charges may be realized by closed strings. The differential underlying the descent construction for Noether charge algebras is shown to be naturally described as a dual of the de Rham differential. The ghost fields used in the construction are shown to be described geometrically as a vielbein with respect to this differential.

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Jia, Bei. "D-branes and K-homology." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/32039.

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In this thesis the close relationship between the topological $K$-homology group of the spacetime manifold $X$ of string theory and D-branes in string theory is examined. An element of the $K$-homology group is given by an equivalence class of $K$-cycles $[M,E,\phi]$, where $M$ is a closed spin$^c$ manifold, $E$ is a complex vector bundle over $M$, and $\phi: M\rightarrow X$ is a continuous map. It is proposed that a $K$-cycle $[M,E,\phi]$ represents a D-brane configuration wrapping the subspace $\phi(M)$. As a consequence, the $K$-homology element defined by $[M,E,\phi]$ represents a class of D-brane configurations that have the same physical charge. Furthermore, the $K$-cycle representation of D-branes resembles the modern way of characterizing fundamental strings, in which the strings are represented as two-dimensional surfaces with maps into the spacetime manifold. This classification of D-branes also suggests the possibility of physically interpreting D-branes wrapping singular subspaces of spacetime, enlarging the known types of singularities that string theory can cope with.
Master of Science

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Condeescu, Cezar. "Non-perturbative effects in string theory." Palaiseau, Ecole polytechnique, 2010. http://pastel.archives-ouvertes.fr/docs/00/56/57/62/PDF/Phd-thesis.pdf.

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On étudie les effets non-perturbatifs généré par des branes instantoniques Euclidiens en compactifications de la théorie des cordes de type I/II avec orientifolds et D-branes magnétisées. Le focus est sur les instantons qui peuvent générer des corrections au superpotentiel. Une condition nécessaire est que les instantons doivent enrouler des cycles rigides. On considère la compactification de la théorie de Type I (IIB) sur l'orientifold T^6/Z_2xZ_2 avec torsion discrète et D-branes magnétisées. Les instantons enroulant le même cycle que l'O-plane exotique (requis par la torsion discrète) ont la structure désiré de modes zéro pour générer des corrections au superpotentiel. On construit des modèles globales basée sur cet orientifold ou les instantons génère des termes linaires et de termes de masse dans le superpotentiel. En théorie des cordes on calcule un couplage physique duquel on doit extraire la partie olomorphique pour obtenir le superpotentiel non-perturbatif. Les facteurs non-olomorphiques sont absorbés dans le potentiel de Kähler et dans redéfinitions des champs chiraux et modules des cordes fermées. On a dérivé ces redéfinitions pour les compactifications toroïdales (avec orientifolds) de la théorie de Type I avec branes magnétisées et lignes Wilson. Finalement, on a considéré des modèles globales avec des termes linéaires. On a calculé explicitement le superpotentiel non-perturbatif pour les orientifolds toroïdales. On a montré comment faire la somme sur les contributions a un instanton. Les modèles analysées possédaient des vides non-perturbatifs supersymétriques ou le group de jauge était brisé et certains modules des cordes ouvertes étaient stabilisés
We study non-perturbative effects generated by Euclidean brane instantons in compactifications of Type I/II string theory with orientifolds and magnetized D-branes. The focus is on instantons which can generate corrections to the superpotential. A necessary condition is that the instantons have to wrap rigid cycles. We consider the compactification of Type I (IIB) on the T^6/Z_2xZ_2 orientifold with discrete torsion and magnetized branes. The instantons wrapping the same cycle as the exotic O-planes (required by the presence of discrete torsion) have the desired uncharged zero-mode structure in order to generate corrections to the superpotential. We build global models based on this orientifold where stringy instantons generate linear terms and mass terms in the superpotential. Typically, in string theory one computes a physical coupling from which one has to extract a holomorphic part in order to obtain the non-perturbative superpotential. Various non-holomorphic factors are absorbed into the Kähler potential and redefinitions of chiral fields and closed string moduli. We have derived these redefinitions in the context of toroidal (orientifold) compactifications of Type I with magnetized branes and continuous Wilson lines. Finally, we have considered global models with linear terms in the superpotential generated non-perturbatively. We have computed explicitly the non-perturbative superpotential for toroidal orientifolds. We show how to sum coherently over the various one-instanton contributions. The explicit models analyzed possessed a non-perturbative supersymmetric vacuum where the gauge group was broken and certain open-string moduli were stabilized

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Srivastava, Yogesh K. "Dynamics of black holes and black rings in string theory." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1181586688.

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Alim, Murad. "Mirror Symmetry, Toric Branes and Topological String Amplitudes as Polynomials." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-103416.

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Björnsson, Jonas. "Strings, Branes and Non-trivial Space-times." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1619.

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This thesis deals with different aspects of string and /p/-brane theories. One of the motivations for string theory is to unify the forces in nature and produce a quantum theory of gravity. /p/-branes and related objects arise in string theory and are related to a non-perturbative definition of the theory. The results of this thesis might help in understanding string theory better. The first part of the thesis introduces and discusses relevant topics for the second part of the thesis which consists of five papers.

In the three first papers we develop and treat a perturbative approach to relativistic /p/-branes around stretched geometries. The unperturbed theory is described by a string- or particle-like theory. The theory is solved, within perturbation theory, by constructing successive canonical transformations which map the theory to the unperturbed one order by order. The result is used to define a quantum theory which requires for consistency d = 25 + p dimensions for the bosonic /p/-branes and d = 11 for the supermembrane. This is one of the first quantum results for extended objects beyond string theory and is a confirmation of the expectation of an eleven-dimensional quantum membrane.

The two last papers deal with a gauged WZNW-approach to strings moving on non-trivial space-times. The groups used in the formulation of these models are connected to Hermitian symmetric spaces of non-compact type. We have found that the GKO-construction does not yield a unitary spectrum. We will show that there exists, however, a different approach, the BRST approach, which gives unitarity under certain conditions. This is the first example of a difference between the GKO- and BRST construction. This is one of the first proofs of unitarity of a string theory in a non-trivial non-compact space-time. Furthermore, new critical string theories in dimensions less then 26 or 10 is found for the bosonic and supersymmetric string, respectively.

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Björnsson, Jonas. "Strings, branes and non-trivial spece-times /." Karlstad : Faculty of Technology and Science, Physics, Karlstads universitet, 2008. http://www.diva-portal.org/kau/abstract.xsql?dbid=1619.

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Krippendorf, Sven-Ludwig. "D-brane model building and moduli stabilisation in type IIB string theory." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609632.

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Berenstein, David Eliecer. "Dynamical aspects of D-branes and matrix theory /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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43

Mayes, Van Eric. "Phenomenology of heterotic and type II orientifold string models." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1597.

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44

Wilshin, Simon. "Identifiable branes and their realisation in toy models of string theory." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534180.

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45

Jusinskas, Renann Lipinski. "Supercordas e Aspectos da Correspondência AdS/CFT." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-14102010-151117/.

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Este é um trabalho de revisão. Os principais formalismos no desenvolvimento da teoria de cordas são introduzidos e discutidos: a corda bosônica e as supercordas no formalismo de Ramond-Neveu-Schwarz e no formalismo de Green-Schwarz. São introduzidas também as açôes efetivas no limite de baixas energias das D-branas (ação DBI) e das teorias de supergravidade (D=10,11). Por fim, são analisados alguns aspectos da correspondência AdS/CFT, enunciando a conjectura e introduzindo algumas das entradas do dicionário. Os apêndices contêm tópicos de grande relevância para o texto e podem ajudar a esclarecer vários raciocínios e passagens ao longo do mesmo.
This is a review work. The main formalisms on the development of string theory are introduced and discussed: the bosonic string and the superstrings formalisms of Ramond-Never-Schwarz and Green-Schwarz. The effective actions in the low energy limit of the D-branes (DBI action) and supergravity theories (D=10,11) are introduced as well. Finally, some aspects of the AdS/CFT correspondence are analised, enunciating the conjecture and introducing some entries of the dictionary. The appendices contains some topics that are highly relevant for the whole text and may help clarify several ideas and arguments through it.

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46

Luckock, H. C. "Strings, p-branes and Skyrmions in curved space." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384005.

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47

Lovis, Kenneth John. "Strings, branes, and gravity duals of gauge theories." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4128/.

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We study the correspondence between certain supersymmetric gauge theories and their dual supergravity descriptions. Using low-energy brane probes of the super-gravity geometries we find moduli spaces of vacua, as expected from considering the dual gauge theories. The metrics on these spaces can be put into a form consistent with field theory expectations. This provides a non-trivial check on the supergravity solutions, in addition to strong-coupling predictions for the gauge theories. In the case of N = 2 supersymmetric gauge theory, proposed supergravity duals have previously been shown, using brane probe techniques, to display the 'enhangon mechanism'. In particular, the supergravity geometries correctly reproduce the per-turbative behaviour of the gauge theory. We calculate exact non-perturbative results at low-energies using the method of Seiberg & Witten. These correctly reproduce the perturbative results in the supergravity limit, but also make predictions for when the supergravity approximation is not valid. Finally, we study the Penrose limit of a geometry that is dual to a known N= 1 superconformal gauge theory. The resulting spacetime is a new plane-wave solution with constant three-form fluxes. We quantize type IIB superstrings on this background using the Green-Schwarz formalism. We find the spectrum of string excitations and discover that it is particularly simple, due to the specific form of the plane-wave background. Using the gauge theory/gravity duality, we make predictions (beyond the supergravity approximation) for gauge theory quantities in the corresponding limit.

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48

Wurtz, Albrecht. "Conformal Field Theory and D-branes." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1346.

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The main topic of this doctoral thesis is D-branes in string theory, expressed in the language of conformal field theory. The purpose of string theory is to describe the elementary particles and the fundamental interactions of nature, including gravitation as a quantum theory. String theory has not yet reached the status to make falsifiable predictions, thus it is not certain that string theory has any direct relevance to physics. On the other hand, string theory related research has led to progress in mathematics.

We begin with a short introduction to conformal field theory and some of its applications to string theory. We also introduce vertex algebras and discuss their relevance to conformal field theory. Some classes of conformal field theories are introduced, and we discuss the relevant vertex algebras, as well as their interpretation in terms of string theory.

In string theory, a D-brane specifies where the endpoint of the string lives. Many aspects of string theory can be described in terms of a conformal field theory, which is a field theory that lives on a two-dimensional space. The conformal field theory counterpart of a D-brane is a boundary state, which in some cases has a natural interpretation as constraining the string end point. The main focus of this thesis is on the interpretation of boundary states in terms of D-branes in curved target spaces.

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49

Pasukonis, Jurgis. "BPS operators and brane geometries." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8614.

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In this thesis we explore the finite N spectrum of BPS operators in four-dimensional supersymmetric conformal field theories (CFT), which have dual AdS gravitational descriptions. In the first part we analyze the spectrum of chiral operators in the free limit of quiver gauge theories. We find explicit counting formulas at finite N for arbitrary quivers, construct an orthogonal basis in the free inner product, and derive the chiral ring structure constants. In order to deal with arbitrarily complicated quivers, we develop convenient diagrammatic techniques: the results are expressed by associating Young diagrams and Littlewood-Richardson coefficients to modifications of the original quiver. We develop the notion of a "quiver character", which is a generalization of the symmetric group character, obeying analogous orthogonality properties. In the second part we analyze how the BPS spectrum changes at weak coupling, focusing on the N = 4 supersymmetric Yang-Mills. We find a formal expression for the complete set of eighth-BPS operators at finite N, and use it to derive corrections to a near-BPS operator. In the third part of this thesis we move on to the strong coupling regime, where the dual gravitational description applies. The BPS spectrum on the gravity side includes D3-branes wrapping arbitrary holomorphic surfaces, a generalization of the spherical giant gravitons. Quantizing this moduli space gives a Hilbert space, which, via duality and nonrenormalization theorems, should map to the space of BPS operators derived in the weak coupling regime. We apply techniques from fuzzy geometry to study this correspondence between D3-brane geometries, quantum states, and BPS operators in field theory.

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50

Lee, Ming-Wen. "Brahms's string quartet in C minor, op. 51, no. 1 : context, analysis and interpretive approaches /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/11265.

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Dissertations / Theses on the topic 'Strong brands'

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